Co2 Levels In The Past

Co2 Levels In The Past
Co2 Levels In The Past Image link: https://en.wikipedia.org/wiki/Coccolithophore
C O N T E N T S:

KEY TOPICS

  • For a 2009 study, published in the journal Science, scientists analyzed shells in deep sea sediments to estimate past CO2 levels, and found that CO2 levels have not been as high as they are now for at least the past 10 to 15 million years, during the Miocene epoch.(More…)
  • The evidence is much firmer for the last 800,000 years, when ice cores show that CO2 concentrations stayed tight between 180 and 290 ppm, hovering at around 280 ppm for some 10,000 years before the industrial revolution hit. (There have been eight glacial cycles over these past 800,000 years, mostly driven by wobbles in the Earth?s orbit that run on 41,000 and 100,000 year timescales).(More…)
  • In 2013, CO2 levels surpassed 400 ppm for the first time, and just four years later, the Mauna Loa Observatory recorded its first-ever carbon dioxide reading above 410 ppm.(More…)
  • Making climate data accessible and user-friendly like this atmospheric CO2 levels graph is a campaign of the 2 Institute (2 Degrees Institute).(More…)

POSSIBLY USEFUL

  • The National Oceanic and Atmospheric Administration (NOAA) reported that carbon dioxide levels in 2016 broke records for the second year in a row with an increase of 3 parts per million (ppm).(More…)
  • Three years later, for the first time since scientists had begun to record them, carbon levels remained above 400 parts per million for an entire month.(More…)

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KEY TOPICS

For a 2009 study, published in the journal Science, scientists analyzed shells in deep sea sediments to estimate past CO2 levels, and found that CO2 levels have not been as high as they are now for at least the past 10 to 15 million years, during the Miocene epoch. [1] The study of past CO2 levels and past climates helps us undersand the condition in which human societies developed. [2] By drilling for ice cores and analyzing the air bubbles, scientists have found that, at no point during at least the past 800,000 years have atmospheric CO2 levels been as high as they are now. [1] CO2 levels are far higher now than they have been for anytime during the past 800,000 years. [1]

Aside from how quickly human-caused CO2 emissions have increased in the past two centuries – ending a slow, natural decline in CO2 levels that lasted hundreds of millions of years beforehand – there’s another somewhat scary factor to be aware of. [3] Reaction to Climate Depot?s 400ppm of CO2: “The Happy Green Planet, Why Has Global Warming Stopped?? “At the end of its distorted and deliberately alarmist article, Bloomberg cites Marc Morano, former spokesman for GOP Senator James Inhofe and the executive editor of Climate Depot, saying the earth has had much higher CO2 levels in the past, and “Americans should welcome the 400 parts-per-million threshold. [4]

Since atmospheric CO2 levels could plausibly double by midcentury, Cox?s results indicate that not only will temperatures soar past 1.5 C, but that they?ll quickly rise higher than Paris? upper limit of 2 degrees. [5]

As for climate states between 2.6 and 5.3 million years ago, during the Pliocene Epoch, atmospheric CO2 levels appear comparable to today, and models suggest that global temperatures were 3°C to 4°C warmer than pre-industrial climates (Yhang et al., 2014). [2] These records tell us about atmospheric CO2 levels and climate that go back befre the development of human civilization. [6] In our 800,000-year record, it took about 1,000 years for CO2 levels to increase by 35 ppm. [7] For the 800,000 years we have records of, average global CO2 levels fluctuated between about 170 ppm and 280 ppm. [7] Emissions from fossil-fuel consumption have remained at historically high levels since 2011, and according to Tans, these emissions are contributing to the dramatic spike in atmospheric CO2 levels, which, up until the industrial revolution in 1760, averaged about 280 ppm. [8] A 2011 study in the journal Paleoceanography found that atmospheric CO2 levels may have been comparable to today’s as recently as sometime between 2 and 4.6 million years ago, during the Pliocene epoch, which saw the arrival of Homo habilis, a possible ancestor of modern homo sapiens, and when herds of giant, elephant-like Mastadons roamed North America. [1] “It is for this reason that some climate scientists, like James Hansen, have argued that even current-day CO2 levels are too high. [1] One 2008 study found that for every degree Celsius the temperature rises because of CO2 levels, ozone pollution can be expected to kill an additional 22,000 people via respiratory illness, asthma, and emphysema. [7] Sea-level rise projections will only get bigger as CO2 levels will continue to climb. [7] In the entire history of human civilization, CO2 levels have never been this high. [1] Regardless of which estimate is correct, it is clear that CO2 levels are now higher than they have ever been in mankind’s history. [1] The average CO2 level doesn’t represent the air most of us breathe. [7]

For the first time in recorded history, the average monthly level of CO2 in the atmosphere exceeded 410 parts per million (ppm) in the month of April, according to observations made at the Mauna Loa Observatory in Hawaii. [7] Global temperature tracks very closely to atmospheric levels of CO2. [7] Cities tend to have far more CO2 than average — and those levels rise even higher indoors. [7]

Today, past and current readings show the continuing, relentless rise in the background level of CO 2 in the atmosphere. [6]

We know that atmospheric CO2 has ranged between 172 and 300 part per million (ppm) for the past 1 million years. [6] The new record is not a coincidence — humans have rapidly transformed the air we breathe by pumping CO2 into it over the past two centuries. [7]

Carbon dioxide levels today are higher than at any point in at least the past 800,000 years. [9] The level of solar output that affects Earth’s atmosphere – called total solar irradiance – has been growing the past hundreds of millions of years as the Sun has grown brighter, but Earth’s climate has kept stable, due to atmospheric CO2 gradually dropping over the same period. [3] There?s a lot of debate about both temperatures and CO2 levels from millions of years ago. [10] CO2 levels were around 280 parts per million prior to the Industrial Revolution in the late 1800s, when large amounts of greenhouse gases began to be released by burning fossil fuels. [11] When scientists (specifically, Ralph Keeling?s father) first started measuring atmospheric CO2 consistently in 1958, at the pristine Mauna Loa mountaintop observatory in Hawaii, the CO2 level stood at 316 parts per million (ppm), just a little higher than the pre-industrial level of 280 ppm. 400 was simply the next big, round number looming in our future. [10]

For the 800,000 years for which we have records, average global CO2 levels fluctuated between about 170 ppm and 280 ppm. [12] The last time CO2 levels were as high as today?s was about 3 million years ago. [10] This might have triggered a massive dip in CO2 levels and a glaciation 300 million years ago. [10]

By looking at what Earth?s climate was like in previous eras of high CO2 levels, scientists are getting a sobering picture of where we are headed. [10] There’s a debate among scientists about the last time CO2 levels were this high. [12] As humans kept digging up carbon out of the ground and burning it for fuel, CO2 levels sped faster and faster toward that target. [10] This story was updated on June 12 to include the newly released data on CO2 levels hitting a new record in May and to clarify the means through which higher levels of CO2 affect human health. [12] Predicting future CO2 levels in the atmosphere is complicated; even if we know what will happen to man-made emissions, which depends on international policies and technological developments, the planet?s network of natural sources and sinks is vast and interlinked. [10] While Mauna Loa has become the global standard for CO2 levels, measurements taken in other places have confirmed the Mauna Loa results. [10] These are the highest CO2 levels in the 800,000 years for which we have good data. [12] Projections of sea-level rise will also get more extreme as CO2 levels continue to climb. [12] At the current rate of growth in CO2, levels will hit 500 ppm within 50 years, putting us on track to reach temperature boosts of perhaps more than 3 degrees C (5.4 F) — a level that climate scientists say would cause bouts of extreme weather and sea level rise that would endanger global food supplies, cause disruptive mass migrations, and even destroy the Amazon rainforest through drought and fire. [10] For the first time in recorded history, the average monthly level of CO2 in the atmosphere exceeded 410 parts per million in April, according to observations at the Mauna Loa Observatory in Hawaii. [12] The last time the planet?s air was so rich in CO2 was millions of years ago, back before early predecessors to humans were likely wielding stone tools; the world was a few degrees hotter back then, and melted ice put sea levels tens of meters higher. [10]

If man-made emissions were to magically drop to zero tomorrow, the concentration of CO2 in the atmosphere would start to level out immediately — but it would probably take about a decade to detect this slowdown against the background of the natural carbon cycle, according to Keeling. [10] Higher levels of CO2 and the warming they cause also exacerbate ozone pollution. [12]

Bloomberg News features Climate Depot’s Morano: ‘The Earth has had many-times-higher levels of CO2 in the past. [4] The gradual rise in the sun?s warmth over the past half a billion years has been balanced by a long-term decline in CO 2 levels, says Foster, keeping the planet?s temperature in the habitable zone – with a little help from plants. [13] This is one of the conclusions of a study looking at how CO 2 levels in the atmosphere have changed over the past half billion years and comparing that with future scenarios. [13] The heavier line joining small squares represents the best estimate of past atmospheric CO 2 levels based on geochemical modeling and updated to have the effect of land plants on weathering introduced 380 to 350 million years ago. [14] Foster and his colleagues have compiled data from more than 100 different studies to produce the best estimate yet of how CO 2 levels changed in the past 420 million years. [13] On this page, we?ll go through these data and the levels and trends of CO 2 in the Earth?s past, what those levels were in Earth?s more recent past, and what CO 2 levels should (approximately) be today. [15]

These gases have caused the Earth’s temperature to rise over the past century to levels that cannot be explained by natural variability. [11] Thanks to bubbles of air trapped in Antarctic ice, we have a good picture of CO 2 levels over the past 800,000 years. [13]

CO2: Past, Present, & Future Time Scavengers meta name”description” content”One of the common themes in the previous pages is the carbon dioxide, CO2, in our atmosphere and oceans. [15] The record is not a coincidence — humans have rapidly transformed the air we breathe by pumping CO2 into it over the past two centuries. [12]

Global mean sea level has been rising at an average rate of 1.7 mm/year (plus or minus 0.5mm) over the past 100 years, which is significantly larger than the rate averaged over the last several thousand years. [16] The last time Earth experienced similar CO2 concentration rates was during the Pliocene era (three to five million years ago), when the sea level was up to 20m higher than now. [17]

This increase matched the record rise recorded in 2015, when CO2 levels officially passed 400 ppm, which climate scientists call the “point of no return.” [18] Canceling CMS likely has global ramifications, Kelly Sims Gallagher, director of Tufts University’s Center for International Environment and Resource Policy, pointed out, because the system monitors the Earth’s CO2 levels as nations that have signed on to the Paris climate agreement –from which Trump plans to withdraw –pursue policies to reduce greenhouse gas emissions. [19] “Based on the laws of physics, the effect on temperature of man?s contribution to atmospheric CO2 levels is minuscule and indiscernible from the natural variability caused in large part by changes in solar energy output.” [4] “Our new information from the deep Earth is independent of, and confirms existing data on, atmospheric CO2 levels as determined from fossils.” [20] While CO2 levels have passed 400 ppm in the Earth’s history, “it has been a long time. [19] Among other things, the analysis shows that while CO2 levels are much lower now than they have been at other, hotter points in Earth’s history, they’re rising incredibly quickly. [3]

Almost never has CO2 levels been as low as it has been in the Holocene (geologic epoch) – 280 (parts per million ppm) – that?s unheard of. [4] It has been a long time since the planet experienced such CO2 levels. [21] With CO2 levels and total solar irradiance both rising – collectively called climate forcing – the team thinks we’re headed into uncharted and potentially very dangerous climactic territory in the future. [3] “The higher CO2 levels have significant effects on the planet’s climate, and its flora and fauna,” he said. [20] The website Real Science celebrated rising CO2 levels, claiming in a May 11, 2013 article that ” Humans Thrive In Increasing CO2.” [4] And, a peer-reviewed study this year found that the present day carbon dioxide level of 400 ppm was exceeded without any human influence 12,750 years ago when CO2 may have reached up to 425 ppm. [4] The effectiveness of CO2 as a greenhouse gas becomes ever more marginal with greater concentration – ?The effectiveness of CO2 as a greenhouse gas diminishes logarithmically with increasing concentration and from the current level of ~390 ppmv, (parts per million by volume). [4] As a recent federal climate science report (coauthored by Hayhoe) noted, the 400 parts per million carbon dioxide level in the Pliocene “was sustained over long periods of time, whereas today the global CO2 concentration is increasing rapidly.” [19]

Levels rose 3 ppm to 405.1 ppm in 2016, putting CO2 at its highest levels in over 10,000 years. [18] Professor Dr. Doug L. Hoffman, mathematician, computer programmer and engineer, wrote on August 24, 2009 : “There have been ice ages when the levels of Co2 in Earth?s atmosphere have been many times higher than today?s.” [4] From 1000AD to 1800, over a period of relatively stable CO2 values that bounced around the 280ppm level, temperatures plummeted in the Little Ice Age (LIA) and then rebounded over a century later. [4]

The evidence is much firmer for the last 800,000 years, when ice cores show that CO2 concentrations stayed tight between 180 and 290 ppm, hovering at around 280 ppm for some 10,000 years before the industrial revolution hit. (There have been eight glacial cycles over these past 800,000 years, mostly driven by wobbles in the Earth?s orbit that run on 41,000 and 100,000 year timescales). [10] New Paper: Danish Physicist Dr. Henrik Svensmark?s Cosmic Jackpot: “Svensmark stands the currently popular CO2 story on its head?Climate and life control CO2, not the other way around? ‘Some geoscientists want to blame the drastic alternations of hot and icy conditions during the past 500 million years on increases and decreases in carbon dioxide, which they explain in intricate ways. [4] In the past, when the Earth?s climate rose, CO2 came out of the ocean, the soils, and the permafrost. [4]

Other analyses have shown CO2 loses any “warming? impact as the levels increase. [4] There were times in the past when the amount was higher, but it took millennia to reach those levels. [4]

In 2013, CO2 levels surpassed 400 ppm for the first time, and just four years later, the Mauna Loa Observatory recorded its first-ever carbon dioxide reading above 410 ppm. [5] Their findings are based on weekly observations of carbon dioxide at Hawaii’s Mauna Loa Observatory, where climate scientists have been measuring CO2 levels since 1958. [22] Global warming continues, and since the climate responds to rising CO2 levels on a delay of decades, there is more warming “in the pipeline,” no matter how quickly we cut fossil fuel emissions. [5] The last time CO2 levels were this high, global surface temperatures were 6 C higher, oceans were 100 feet higher, and modern humans didn?t exist. [5] Its first reading of atmospheric CO2 levels clocked in at 280 parts per million (ppm). [5] CO2 levels may not have doubled from pre-industrial levels yet, but they?re increasing at an alarming rate. [5]

Average concentrations of CO2 in the atmosphere are now at 403.3ppm (parts per million), up from 400ppm in 2015 and way above the less than 280ppm levels in the atmosphere before the industrial era. [23] The report warned that increasing levels of CO2 in the atmosphere “have the potential to initiate unprecedented changes in climate systems,” leading to “severe ecological and economic disruptions.” [23] While plant biologists have been studying how different trees and crops respond to increasing carbon dioxide levels, this study is one of the first to show that when plants change the way they function as CO2 rises or falls, it can have major impact, even to the point of extinction. [24] For instance, around 12,000 years ago, at the start of the Holocene, CO2 spiked to a higher level than now. [24] The current unprecedented rate of rising atmospheric CO2 raises concerns about melting ice sheets, rising sea level, major climate change, and biodiversity loss – all of which were evident more than 300 million years, the only other time in Earth’s history when high CO2 accompanied ice at the polar regions. [24]

It’s a banner week for the end of the world, because we’ve officially pushed atmospheric carbon levels past their dreaded 400 parts per million. [22] Global temperatures have already risen 0.8 degrees celsius since pre-industrial levels, and the past few years have provided grave indications that things are heating up. [5] A sustained effort by many geochemists and their allies managed to get numbers for the “climate sensitivity” in past eras, that is, the response of temperature to a rise in the CO 2 level. [25] By 2010, new studies had pinned down some truly disturbing numbers about eras in the distant past when CO 2 levels had been high — although no higher than we would reach by the late 21st century if emissions continued to rise without restriction. [25] By the 1980s, scientists turned up evidence suggesting that CO 2 levels had been elevated during the great warm eras of the past. [25] These scientists were interested chiefly in the possibility that a lower level of carbon dioxide gas might explain the ice ages of the distant past. [25] The Earth also gives us clues about the levels of greenhouse gases that existed in the past. [26]

Making climate data accessible and user-friendly like this atmospheric CO2 levels graph is a campaign of the 2 Institute (2 Degrees Institute). [27] This graph features atmospheric CO2 levels that combine measurements from as far back as 800,000 years up to the present day with an atmospheric temperature overlay option. [27] A new study suggests that if emissions are left unchecked we could be on track to return to those CO2 levels in the next few centuries, and with a little help from a brighter, hotter Sun, surface temperatures on Earth could soar to new heights. [28] The last time that CO2 levels were in the range near a thousand, was about 55 million years ago. [29] When the elder Keeling started at Mauna Loa, the CO2 level was at 315 ppm. [30] CO2 levels are updated daily with data directly from NOAA’s science lab on the slopes of Moana Loa volcano on the Big Island of Hawaii. [27] The ” Keeling curve,” showing the steady climb in CO2 levels caused primarily by burning fossil fuels, has become an icon of climate change. [30]

The above chart shows the relative changes in global average temperature, CO2 (carbon dioxide), and sea level over the last 420,000 years. [29] From 1917 to 2017 globally averaged CO2 (carbon dioxide) levels have increased by about 105 ppmv: from about 302 ppmv in 1917 (from analysis of ice cores bubbles) to the present 406.7 ppmv (from Mauna Loa direct measurements, through July, 2017). [31]

The current unprecedented rate of rising atmospheric CO2 raises concerns about melting ice sheets, rising sea level, major climate change, and biodiversity loss — all of which were evident more than 300 million years, the only other time in Earth?s history when high CO2 accompanied ice at the polar regions. [32] Raymo’s best guess at the moment, to be confirmed by further fieldwork and modeling, is that the last time Earth had 400 ppm of CO2 in its atmosphere, sea level was somewhere between 10 meters (33 feet) and 20 meters (66 feet) higher than today. [30]

Yet the two main drivers of climate–the level of CO2, and the parameters of Earth’s orbit, which determine how much sunlight falls where and at what season–were essentially the same as today. [30]

Atmospheric carbon dioxide levels, as measured in air, are higher today than at any time during the past 800,000 years. [33] The Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 800,000 years. [27] A new report from the American Meteorological Society shows that Earth?s atmosphere had the highest levels of carbon dioxide in the atmosphere in 2017 than it’s had in the past 800,000 years. [34] In 2017, Earth?s atmosphere had higher levels of the main greenhouses gases–carbon dioxide, methane and nitrous oxide–than it?s ever had in the past 800,000 years, according to a new report. [34]

While sea level and climate have changed in the past, it was LONG before our human civilization. [29]

POSSIBLY USEFUL

The National Oceanic and Atmospheric Administration (NOAA) reported that carbon dioxide levels in 2016 broke records for the second year in a row with an increase of 3 parts per million (ppm). [8] The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age 11,000-17,000 years ago. [9]

Evidence suggests that it has likely been millions of years since atmospheric CO2 and global temperatures were higher than they are today (Hönisch et al., 2009; Yhang et al., 2013; Zhang et al, 2014). [2] CO2.Earth spotlights Year 2100 projections for atmospheric CO2, atmospheric GHGs (CO2-equivilent), GHG emissions, and global temperature. [6]

Carbon dioxide is the most important long-lived global warming gas, and once it is emitted by burning fossil fuels such as coal and oil, a single CO2 molecule can remain in the atmosphere for hundreds of years. [1] The numbers show that the rate of CO2 in the atmosphere is now at 405.1 ppm, the highest it has been in more than 10,000 years. [8] The first time in human history that atmospheric CO2 exceeded 300 ppm was about the time the Titanic sank in the North Atlantic Ocean. [6] The last time there was this much carbon dioxide (CO2) in the Earth’s atmosphere, modern humans didn’t exist. [1]

Two decades ago, the international community agreed on an ultimate climate objective to stabilize the concentration of CO2 and other greenhouse gases in the atmosphere. [6]

The earth cycled through cold glacial and warm inter-glacial periods without atmospheric CO2 exceeding 300 ppm. [6] The International Panel on Climate Change uses 1750 as its pre-industrial baseline to show changes in atmospheric CO2, global temperature and other climate indicators in the post-industrial era after 1750. [6] Aside from the high-precision CO2 measurements that Charles David Keeling started at the South Pole in 1957 and the Mauna Loa Observatory in 1958, ice cores are the best source of atmospheric CO2 data for the prior 1 million years. [2] The data includes a composite for atmospheric CO2 data that spans 800,000 years. [2]

Atmospheric carbon dioxide concentrations in parts per million (ppm) for the past 800,000 years, based on EPICA (ice core) data. [9] Scientists are able to analyze the cores to learn about past changes in the concentration of atmospheric gases and the glacial-interglacial cycles for the past million years. [2] Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. [2] The past decade has been the hottest ever recorded since global temperature records began 150 years ago. [35] As we learn about the past, the facts of warmer climates so long ago has less immediate relevance for our species that emerged just 200,000 years ago. [2] The study of past climates before human influence became signficant helps us understand how different parts of the earth system change over short and very long time scales. [6] While there have been past periods in Earth’s history when temperatures were warmer than they are now, the rate of change that is currently taking place is faster than most of the climate shifts that have occurred in the past, and therefore it will likely be more difficult to adapt to. [1] Over the past decade, however, the growth rate has been closer to 2.3 ppm per year. [9] Based on air bubbles trapped in mile-thick ice cores (and other paleoclimate evidence), we know that during the ice age cycles of the past million years or so, carbon dioxide never exceeded 300 ppm. [9] Natural increases in carbon dioxide concentrations have periodically warmed Earth?s temperature during ice age cycles over the past million years or more. [9]

Use the CO 2 data and graphs to explore changes in the past, from a thousand to a million years before present. [2]

CO 2.Earth uses the most current data from the atmosphere to show the planetary trend for Earth’s backgrond CO 2 level. [6] If fossil-fuel burning continues at a business-as-usual rate, such that humanity exhausts the reserves over the next few centuries, CO 2 will continue to rise to levels of order of 1500 ppm. [35] In 2013, CO 2 levels surpassed 400 ppm for the first time in recorded history. [35] Lower levels occured between 1550 and 1800 A.D. These ice cores show major growth in atmospheric CO 2 levels in the industrial period except 1935-1945 A.D. when levels stabilized or decreased slightly. [2] The records extend into recent decades for which instrument measurements of atmospheric CO 2 levels occured. [2]

The atmosphere would then not return to pre-industrial levels even tens of thousands of years into the future. [35] In recent years, we’ve pushed those gas levels into uncharted territory. [7]

The last time the atmospheric CO 2 amounts were this high was more than 3 million years ago, when temperature was 2-3C (3.6-5.4F) higher than during the pre-industrial era, and sea level was 15-25 meters (50-80 feet) higher than today. [9] Sea levels are increasing today in response to the warming climate, as ice sheets melt and seas expand due to rising temperatures. [1]

The peaks and valleys in carbon dioxide levels track the coming and going of ice ages (low carbon dioxide) and warmer interglacials (higher levels). [9]

“The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last Ice Age,” Tans said in a press release. [8] As we near the record for the highest CO2 concentration in human history — 400 parts per million — climate scientists worry about where we were then, and where we’re rapidly headed now. [1] Earth’s atmospheric CO2 concentration first crept above 400 parts per million in 2013. [7]

The human health effects from CO2 increases are just one part of the bigger story here. [7] Global CO2 emissions reached a record high of 35.6 billion tonnes in 2012, up 2.6 percent from 2011. [1] Now, the crossover to concentrations that stay above 400 ppm CO2 is nearly complete. [6] President Obama’s EPA ruled in 2009 that CO2 was a pollutant that needed to be regulated under the Clean Air Act, though the Trump administration is re-evaluating that decision. [7] Keeling is the son of Charles David Keeling, who began the CO2 observations at Mauna Loa in 1958 and for whom the iconic ” Keeling Curve ” is named. [1] With global CO2 emissions continuing on an upward trajectory that is likely to put CO2 concentrations above 450 ppm or higher, it is extremely unlikely that the steadily rising shape of the Keeling Curve is going to change anytime soon. [1]

Multiple records are integrated with observations of the contemporary earth sysem to reconstruct past atmospheres and climates. [2] Ice core records provide a high-resolution proxy record of past atmospheres and climates. [2] To understand past climates, ice cores provide a high-resolution record of key climate variables that span the period in which homo sapiens appeared and human civilization developed. [2]

Studying ice cores and other proxy data tells us a lot about how the slow and fast earth system have adjusted to changes in the past. [6]

Of significance to the composition of past atmospheres, Bärbel Hönisch and other scientists (2009) analyzed a sediment core taken from the bottom of the Atlantic ocean west of Sierra Leone. [2] Areas with accumulating snow turn to ice with air bubbles that preserve samples of the atmosphere from world atmospheres of the past. [2]

It has less relevance for the stable conditions in which civilization developed over the past 12,000 years. [2]

We have a pretty good idea of what Earth’s atmosphere has looked like for the past 800,000 years. [7]

Video: Global sea level rise is accelerating incrementally over time rather than increasing at a steady rate. [35] Scientists are projecting up to 3 feet or more of global sea level rise by 2100, which would put some coastal cities in peril. [1] Our scientists publish and our journalists report on climate science, energy, sea level rise. [1] So sea level was considerably higher — around 100 feet higher — than it is today,” said Pennsylvania State University climate scientist Michael Mann, in an email conversation. [1] Staff members are authorities in communicating climate and weather links, sea level rise, climate. [1] To sum it up, levels this high throw the whole balance of the climate cycle into chaos, making it more difficult to predict climate changes and causing sea level rise, severe tropical storms, drought and flooding. [8] It might have happened during the Pliocene era, between 2 and 4.6 million years ago, when sea levels were at least 60 to 80 feet higher than today. [7] Video: total sea level change between 1992 and 2014, based on data collected from the TOPEX/Poseidon, Jason-1 and Jason-2 satellites. [35]

Atmospheric CO2 concentrations over the Last Glacial Termination. [2] The Keeling Curve, showing CO2 concentrations increasing to near 400 ppm in 2013. [1]

Atmospheric concentrations of CO2 are now above 400 parts per million year-round globally, and last year surpassed 400 ppm at the South Pole. [10] As ofDecember 2008, the concentration of CO2 in Earth?s atmosphere was about 386 parts per million (ppm), with a steady recent growth rate of about 2 ppm per year. [16]

Their compilation suggests that the concentration of CO 2 in the atmosphere never rose above 3000 parts per million during this time period, whereas some earlier studies have suggested levels were as high as 5000 ppm at times. [13] Earth’s carbon dioxide levels continue to soar, at highest point in 800,000 years Carbon dioxide — the gas scientists say is most responsible for global warming — reached its highest level in recorded history last month, at 410 parts per million. [11] Pre-industrial levels of carbon dioxide (prior to the start of the Industrial Revolution) were about 280 parts per million by volume (ppmv), and current levels are greater than 380 ppmv and increasing at a rate of 1.9 ppm yr-1 since 2000. [16] Prior to the onset of the Industrial Revolution, carbon dioxide levels had fluctuated over the millennia but had never exceeded 300 parts per million. [11]

The industrial activities that our modern civilization depends upon have raised atmospheric concentrations of carbon dioxide and methane to higher levels than at any point during the last 650,000 years. [16] Atmospheric CO 2 levels (blue line) and temperature (red line) from year 1,000 to 1978. [15] In very general terms, long-term reconstructions of atmospheric CO 2 levels going back in time show that 500 million years ago atmospheric CO 2 was some 20 times higher than present values. [14] The last time CO 2 levels were this high was the mid-Pliocene warm period — about three million years ago. [36] The last time carbon dioxide levels reached 400 ppm was 3-5 million years ago, in the mid-Pliocene era. [37] Since of the Earth’s atmosphere is out-of-balance with the conditions expected from simple chemical equilibrium, it is very hard to say what precisely sets the level of the carbon dioxide content in the air throughout geologic time. [14] The black arrow shows the huge amount of genera that originated during this time in Earth’s history when atmospheric CO 2 levels were high. [15] For most of human evolution, CO 2 levels hovered around 278 ppm, helping to maintain the global climate in a relatively stable state conducive to agriculture and the growth of human populations. [36] The non-profit Global Carbon Project estimates that the planet?s current trajectory of emissions is on track to meet the national commitments made as part of the Paris Agreement up to 2030, but not to meet the long-term goal of stabilizing the climate system below 2 degrees C above pre-industrial levels. [10] Global temperatures have risen in parallel, with 2016 standing as the hottest year since records started in 1880: 2016 was about 1.1 degrees C (2 F) warmer than pre-industrial levels. [10] Levels of carbon dioxide go up and down each year, reaching their highest levels in May and then going back down in the fall as plants absorb the gas. [11] Some of clearest evidence that global climate change is indeed occuring today and is being caused by human activity comes from carbon dioxide levels in the atmosphere. [16] For environmental scientists and advocates grappling with the invisible, intangible threat of rising carbon dioxide levels in the atmosphere, this symbolic target has served as a clear red line into a danger zone of climate change. [10] We are pumping carbon dioxide into the atmosphere so fast that it could soar to its highest level for at least 50 million years by the middle of this century. [13] A United Nations agency says the amount of carbon dioxide in the atmosphere shot up to its highest level in 800,000 years. [11] Initially, the amount of CO 2 in the atmosphere would continue to rise for a number of reasons, but would then level off and begin to decrease. [15] By looking at future CO 2 emission scenarios, they say the level will soon reach its highest for at least 50 million years – at around 600 ppm. [13] In the IPCC?s most pessimistic scenario, where the population booms, technology stagnates, and emissions keep rising, the atmosphere gets to a startling 2,000 ppm by about 2250. (All the IPCC scenarios presume that mankind?s impact on the atmosphere levels out by 2300.) [10] If you completely ignore the questions of what society might do to curb emissions, and what the planet might do to suck them up, and just look purely mathematically at where the Keeling Curve is going, levels cross 500 ppm around 2050. [10] Human CO 2 emissions from sources such as coal, oil, cement and deforestation reached a record in 2016, and the El Niño weather pattern gave CO 2 levels a further boost, the WMO said. [37] Throughout its history, the Earth has experienced very high levels of CO 2 ; these are called greenhouse times. [15] What?s not in doubt is that when CO 2 levels were higher than in pre-industrial times, the planet was much warmer and had no ice at the poles. [13] The same chart as above, with a focus on the high atmospheric CO 2 levels in the Ordovician and Silurian and Mesozoic. [15] We?ll also talk briefly about the CO 2 levels our Earth may experience in the near future. [15] Vertical bars represent independent estimates of CO 2 level based on the study of ancient soils. [14]

Scientists know prehistoric levels from tiny air bubbles found in ancient Antarctic ice cores, and they can derive even older data from fossils and chemicals trapped in sediment. [37] Carbon dioxide levels are much higher than they would naturally be if we were not burning so much fossil fuel (like oil, gas and coal). [16]

Concentrations of atmospheric CO2 soared in recent decades as industrialized nations continued to pour carbon dioxide into the atmosphere and emissions in developing nations rose steeply. [10] These graphs from the Intergovernmental Panel on Climate Change show projected concentrations of CO2 and projected temperature increases under different emissions scenarios, extending to the year 2500. [10] The global concentration of CO2 in our atmosphere today far exceeds the natural range over the last 650,000 years of 180 to 300 ppmv. [16] Current atmospheric concentrations of CO2 are about 30% higher than they were about 150 years ago at the dawn of the industrial revolution. [16] Last year marked the first time in several million years that atmospheric concentrations of CO2 passed 400 parts per million. [10] Thanks to earth-shaking, slow-moving forces like plate tectonics, mountain building, and rock weathering — which absorb CO2 — atmospheric concentration of CO2 generally declined by about 13 ppm per million years, with a few major wobbles. [10] The last time the planet had a concentration of 300 to 400 ppm of CO2 in the atmosphere was during the mid-Pliocene, 3 million years ago — recently enough for the planet to be not radically different than it is today. [10] “Reaching 400 ppm is a stark reminder that the world is still not on a track to limit CO2 emissions and therefore climate impacts,” said Annmarie Eldering, deputy project scientist for NASA?s Orbiting Carbon Observatory-2 satellite mission at the Jet Propulsion Laboratory. [10] The start of Keeling?s effort was well timed: the 1950s was also when man-made emissions really began to take off, going from about 5 billion tons of CO2 per year in 1950 to more than 35 billion tons per year today. [10] The amount of human-produced CO2 emissions absorbed by plants varies from as little as 30% to as much as 80% from year to year. [16]

Natural sources of CO2, from forest fires to soil and plant respiration and decomposition, are much bigger than that — about 30 times larger than what mankind produces each year. [10] One of the strongest pieces of evidence for human-induced climate change is the consistent rise in carbon dioxide (CO2) in modern times, as measured at the Mauna Loa Observatory in Hawaii, where CO2 has been observed since 1958. [16] CO2 is it is one of the major drivers of long-term atmosphere and ocean changes on our Earth through time and is often mentioned when discussing climate change. [15] “If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted? CO2 will need to be reduced? to at most 350 ppm,” Columbia University climate guru James Hansen has said. [10]

“Globally averaged concentrations of CO2 reached 403.3 parts per million (ppm) in 2016, up from 400.00 ppm in 2015 because of a combination of human activities and a strong El Ni event,” according to The Greenhouse Gas Bulletin, the UN weather agency?s annual flagship report. [17] “Without rapid cuts in CO2 and other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement,” World Meteorological Organisation chief Petteri Taalas said in a statement. [17] Real emissions plotted against the IPCC?s projections of CO2 emissions and temperature increases through 2100. [10]

During the end-Triassic extinction 200 million years ago, for example, CO2 values jumped from about 1,300 ppm to 3,500 ppm thanks to massive volcanic eruptions in what is now the central Atlantic. [10] In May 2013, at the time of the usual annual maximum of CO2, the air briefly tipped over the 400 ppm mark for the first time in several million years. [10] In the big picture, 400 ppm is a low-to-middling concentration of CO2 for the planet Earth. [10] That was eventually followed by a period of massive volcanic activity as the supercontinent ripped apart, spewing out enough CO2 to more than double its concentration in the air. [10]

People don?t always produce more CO2 from one year to the next. [16] Ralph Keeling and his late father Charles David Keeling have kept carbon dioxide (CO2) measurements at the Mauna Loa Observatory in Hawaii since 1958. [11] Atmospheric CO2 as measured from the Mauna Loa Observatory. [15] Rising to 3,400 meters (11,155 feet) in the middle of the ocean, Mauna Loa samples an air mass that has already been well mixed from the inputs and outputs of CO2 far below and far away. [10] In the Northern Hemisphere (where the Mauna Loa observatory is based, and also where most of the planet?s landmass and land-based plants sit), the air in spring is filled with the CO2 released by soil microbes in the thawing snow, and by autumn the CO2 has been vacuumed up by a burst of summer plant life; hence the annual high in May and low in September. [10]

The accumulation of CO2 in the atmosphere continues to rise, as shown in the graph to the right. [16] If we keep adding huge amounts of CO2 into the atmosphere, our surface oceans will become more acidic, leading to increased extinctions of animals. [15] Over the long term, just over half of the CO2 we add to the atmosphere remains there for as long as a century or more. [16]

The parameter RCO 2 is defined as the ratio of the mass of CO 2 in the atmosphere at some time in the past to that at present (with a pre-industrial value of 300 parts per million). [14] Within the past 57 years alone, the amount of CO 2 in the atmosphere has risen by 100 ppm, the same amount that differentiates a glacial from an interglacial period in the previous 800,000 years of Earth’s history. [15] S cientists have several methods of how we determine the amount of CO 2 that was in Earth?s oceans and atmosphere at different times in the geologic past. [15] History of Atmospheric CO 2 through geological time (past 550 million years: from Berner, Science, 1997). [14] This is after the study by Royer et al. (2004), who compiled several different atmospheric CO 2 measurements from different proxies and plotted them against geologic time to uncover the general trend of CO 2 in the past. [15] The first part of this statement is correct: CO 2, at times, was much higher than today in the geologic past. [15]

The increase of 3.3 ppm is considerably higher than both the 2.3 ppm rise of the previous 12 months and the average annual increase over the past decade of 2.08ppm. [17] While natural variations have altered the climate significantly in the past, it is very unlikely that the changes in climate observed since the mid-20th century can be explained by natural processes alone. [16]

CO2 measured here is in parts per million (ppm), which is similar to ppmv. [15] The human-health effects of CO2 increases are just one part of the bigger story here. [12]

CO2 doesn’t directly harm human health at these concentrations. [12] This is the benchmark against which scientists usually note the unprecedented modern rise of CO2. [10] Frighteningly, this modern rise of CO2 is also accelerating at an unusual rate. [10] For these reasons, President Barack Obama’s EPA ruled in 2009 that CO2 was a pollutant that needed to be regulated under the Clean Air Act. [12]

Ocean circulation is becoming more sluggish from melting ice, and the oceans are in danger of becoming increasingly stratified, which could lead to decreased oxygen levels in our oceans. [15] “During that period, global mean surface temperatures were 2-3°C warmer than today, ice sheets in Greenland and West Antarctica melted and even parts of East Antarctica’s ice retreated, causing the sea level to rise 10-20 m higher than that today,” the WMO bulletin said. [37] Humans all over the world are feeling the effects of the huge increase in CO 2, which is causing stronger storms, droughts, sea level rises, and the spread of tropical animals like mosquitoes that carry diseases (e.g., the Zika virus ). [15] The climate cooled as the planet acquired mountain ranges (like the Himalayas) and as sea level dropped. [14] It might have been during the Pliocene era, 2 million to 4.6 million years ago, when sea levels were 60 to 80 feet higher than today. [12] Back then, temperatures were 2 degrees C to 3 degrees C (3.6 to 5.4 F) above pre-industrial temperatures (though more than 10 degrees C hotter in the Arctic ), and sea levels were at least 15-25 meters higher. [10]

Over the past 800,000 years, atmospheric CO 2 has oscillated between 280 and 180 ppmv. [15] Over the past 800,000 years, CO 2 has remained largely between 280 and 180 ppmv CO 2, a change of only 100 ppmv CO 2. [15]

This amount is highest in at least the past 800,000 years, according to the Scripps Institute of Oceanography. [11]

The excess produced by mankind?s thirst for energy is what makes the CO2 concentration in the air go up and up. [10]

As the Trump administration charges forward with its war on science by canceling a ” crucial ” carbon monitoring system at NASA, scientists and climate experts are sounding alarms over atmospheric concentrations of carbon dioxide (CO2) that just surpassed a ” troubling ” threshold for the first time in human history. [19] “This means that, although carbon dioxide concentrations were high hundreds of millions of years ago, the net warming effect of CO2 and sunlight was less.” [3]

Concentrations of carbon dioxide in the atmosphere persisted at levels above 400 parts per million for the first time in recorded history, signposting a “point of no return”. [38] By analyzing the chemistry of bubbles of ancient air trapped in Antarctic ice, scientists have been able to determine the composition of Earth’s atmosphere going back as far as 800,000 years, and they have developed a good understanding of how carbon dioxide levels have varied in the atmosphere since that time. [39]

Carbon dioxide levels rose more than 2 parts per million (ppm) for the second year in a row, according to the National Oceanic and Atmospheric Administration. [18] The level of carbon dioxide, a trace essential gas in the atmosphere that humans exhale from our mouths, has come very close to reaching the “symbolic” 400 parts per million (ppm) threshold in the atmosphere. [4] “During the Middle Miocene (the time period approximately 14 to 20 million years ago), carbon dioxide levels were sustained at about 400 parts per million, which is about where we are today,” Tripati said. [39] “A slightly shocking finding,” Tripati said, “is that the only time in the last 20 million years that we find evidence for carbon dioxide levels similar to the modern level of 387 parts per million was 15 to 20 million years ago, when the planet was dramatically different.” [39]

Levels of carbon dioxide have varied only between 180 and 300 parts per million over the last 800,000 years — until recent decades, said Tripati, who is also a member of UCLA’s Institute of Geophysics and Planetary Physics. [39] Prior to the Industrial Revolution of the late 19th and early 20th centuries, the carbon dioxide level was about 280 parts per million, Tripati said. [39] Some projections show carbon dioxide levels rising as high as 600 or even 900 parts per million in the next century if no action is taken to reduce carbon dioxide, Tripati said. [39] Until now, the scientific community believed that carbon dioxide levels were as high as 2000 parts per million during the Eocene era. [40] “We have shown that this dramatic rise in sea level is associated with an increase in carbon dioxide levels of about 100 parts per million, a huge change,” Tripati said. [39] Peer-reviewed studies have documented that there have been temperatures similar to the present day on Earth when carbon dioxide was up to twenty times higher than today?s levels. [4] You would have to go back at least 15 million years to find carbon dioxide levels on Earth as high as they are today, a UCLA scientist and colleagues report Oct. 8 in the online edition of the journal Science. [39] The 400 ppm level, known as the “carbon threshold,” was long used by scientists as a warning that once we passed this mark, the climate cycle would be thrown into turmoil. [18] Despite the man-made global warming fear movement?s clarion call of alarm, many scientists are dismissing the 400ppm level of carbon dioxide as a non-event. [4] It is global warming that triggers higher levels of carbon dioxide in the atmosphere, not the other way round?A large number of critical documents submitted at the 1995 U.N. conference in Madrid vanished without a trace. [4]

This chart shows carbon dioxide levels for different times in Earth?s history. [39] “We report evidence for a very close coupling between carbon dioxide levels and climate. [39] It has been known that modern-day levels of carbon dioxide are unprecedented over the last 800,000 years, but the finding that modern levels have not been reached in the last 15 million years is new. [39] There has been little agreement before this study on how to reconstruct carbon dioxide levels prior to 800,000 years ago. [39] Such levels may have been reached on Earth 50 million years ago or earlier, said Tripati, who is working to push her data back much farther than 20 million years and to study the last 20 million years in detail. [39] In the last 20 million years, key features of the climate record include the sudden appearance of ice on Antarctica about 14 million years ago and a rise in sea level of approximately 75 to 120 feet. [39] In the mid-Pliocene warm period more than 3 million years ago, they were also around 400 parts per million–but Earth’s sea level is known to have been 66 feet or more higher, and the planet was still warmer than now. [19]

Scientists say that marine proxy records “ place constraints ” on determining past atmospheric carbon dioxide levels—in other words, they give us an approximate range, but we can’t measure it down to one or two parts per million. [21] Thanks largely to our burning of fossil fuels, the average carbon dioxide concentration of the Earth’s atmosphere surged past 400 parts per million in March. [21]

CO 2 concentration in the atmosphere has never fallen below about 180 ppm for at least the past 650,000 years. [41] “The rate of increase of atmospheric CO 2 over the past 70 years is nearly 100 times larger than that at the end of the last ice age,” the authors of the report explained in a statement. [38] “The cessation of observed global warming for the past decade or so has shown how exaggerated NASA’s and most other computer predictions of human-caused warming have been–and how little correlation warming has with concentrations of atmospheric carbon dioxide. [4]

It is not simply, the sun or CO2 when looking at global temperatures, it is the Sun, volcanoes, tilt of the Earth?s axis, water vapor, methane, clouds, ocean cycles, plate tectonics, albedo, atmospheric dust, Atmospheric Circulation, cosmic rays, particulates like Carbon Soot, forests and land use, etc. Climate change is governed by hundreds of factors, or variables, not just CO2. [4] No Correlation Between Global Sea Ice Area And CO2: “Since Earth passed Hansen?s tipping point of 350 ppm CO2, there has been no trend in global sea ice area. [4] Scientists also note that geologically speaking, the Earth is currently in a “CO2 famine” and that the geologic record reveals that ice ages have occurred when CO2 was at 2000 ppm to as high as 8000ppm. [4] Scientists have known for some time that a large amount of volcanic activity results in more CO2 than is present on Earth today, but with previous methods, it had been tricky to come up with a reliable estimate. [20] JunkScience.com: NOAA Debunks 400 ppm CO2 Panic: Last time CO2 at 400 ppm Earth was “much warmer than today? and sea-level was 10-20 meters higher: “So it doesn?t sound like CO2 is too has much to do with temperature or sea-level. [4]

Concentration of CO2 stood at 280 parts per million (ppm) in the atmosphere during the pre-industrialisation era, but this rose to above 400 ppm in 2016. [3] If that the atmosphere was “saturated” with CO2 at 400 ppm, then global warming alarmism would be over. [4] The claim by global warming activists and scientists that CO2 is the global temperature “control knob” has been challenged in the peer-reviewed literature and the Earth?s geologic history. [4] Scientists point out that there are literally hundreds of factors that govern Earth?s climate and temperature – not just CO2. [4] Top Swedish Climate Scientist Dr. Lennart Bengtsson, formerly of the UN IPCC, declared CO2″s “heating effect is logarithmic: the higher the concentration is, the smaller the effect of a further increase.” [4] “However, because the Sun was dimmer back then, the net climate forcing 200 million years ago was lower than we would experience in such a high CO2 future,” Foster explains in a press release. [3] Advocates of this approach are working on atmospheric CO2 estimates going back hundreds of millions of years, but the technique is still very new and the estimates feature a fairly large range of uncertainty. (The early results suggest that the Earth may have experienced 400 ppm or higher of CO2 as recently as two million years ago.) [21] “The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last Ice Age.” [18] “For the first time, we have quantified in this study the link between plate tectonics and volcanic CO2 emissions — a major step forward in understanding and predicting the behavior of the Earth, and its consequences.” [20] The scientists then inserted this number into a comprehensive, commonly used paleoclimate model, to calculate how all the volcanic CO2 emissions at the time would have added up. [20] “CO2 emissions make absolutely no difference one way or another?.Every scientist knows this, but it doesn?t pay to say so?Global warming, as a political vehicle, keeps Europeans in the driver?s seat and developing nations walking barefoot.” [4] UK Professor Emeritus of Biogeography Philip Stott of the University of London explains the crux of the entire global warming debate and rebuts the notion that CO2 is the main climate driver. [4] Global warming activists “are busy claiming that 400 PPM CO2 will destroy the human race. [4] CO2 increases of 80ppm to 100ppm are normal : “While CO2 has increased by 85 ppm from when measurements began in 1958 and are estimated to have risen by 120 ppm since 1750, we should also realize that increases of 80 ppm to 100 pm occurred during the last 3 glaciations without humans burning fossil fuels. [4] While the planet’s concentrations of carbon dioxide fluctuated between roughly 200 ppm and 280 ppm for hundreds of thousands of centuries, as the NASA chart below details, CO2 concentrations have soared since the start industrial revolution–and, without urgent global efforts to significantly alter human activities that produce greenhouse gas emissions, show no sign of letting up. [19]

The aim has been to demonstrate how variations in plate tectonics have led to variations in CO2 emissions from volcanoes 250 million years ago. [20] Van der Meer’s team used a cutting-edge imaging technique called seismic tomography to reconstruct 250 million years of volcanic CO2 emissions. [20]

It has rarely been cooler.” ( LINK ) ” claims that temperature increases solely because more CO2 in the atmosphere traps the sun?s heat. [4] Renowned climatologists have declared that a doubling or even tripling of CO2 would not have major impacts on the Earth?s climate or temperature. [4] Update : In 2014, Giegengack told Climate Depot : ” The Earth has experience d very few periods when CO2 was lower than it is today.” [4] New York times reporter Justin Gillis compared trace amounts of CO2 to “a tiny bit of arsenic or cobra venom” and warned that rising CO2 means “the fate of the earth hangs in the balance.” [4] Plimer, who authored the skeptical book Heaven and Earth, added, “On all time scales, there is no correlation between temps and CO2. [4] JunkScience.com: Stupidest 400 ppm CO2 headline — “World Hits Dreaded CO2 Saturation Level? — No, the 24-hour average at Mauna Loa was measured at 400 ppm for the first time. [4] The foraminifera, unfortunately, can’t tell us exactly when the atmosphere last hit 400 ppm of CO2. [21]

Many skeptical scientists point out that temperature leads CO2 in the ice core data. [4] “More than 700 scientists from 400 institutions in 40 countries have contributed peer-reviewed papers providing evidence that the Medieval Warm Period was real, global, & warmer than the present? – when CO2 was presumably lower. [4]

As temperature rises, CO2 rises, and vice versa,” Giegengack explained. [4] Today as temperatures rise, excess CO2 is instead going into those and other reservoirs. [4] Meteorologist Tom Wysmuller: “The Recent Temperature and CO2 Disconnect? Even going back ten centuries, there have been total disconnects between temperature and the CO2 impact, or lack thereof. [4] It?s easier to say temperature drives CO2,” he added. ( LINK ) “The driving mechanism is exactly the opposite of what Al Gore claims, both in his film and in that book. [4]

“Many people don?t realize that over geological time, we?re really in a CO2 famine now. [4] This process, called subduction,led to volcanism at the surface, with rocks constantly melting and emitting CO2 into the atmosphere. [20] Princeton?s Dr. Happer, who has authored 200 peer-reviewed scientific papers, explained in Senate testimony in 2009 that the Earth is currently in a “CO2 “famine. ? Happer explained to Congress: “Warming and increased CO2 will be good for mankind?’CO2 is not a pollutant and it is not a poison and we should not corrupt the English language by depriving ‘pollutant’ and ‘poison’ of their original meaning,” Happer added. [4] Ivy League geologist Dr. Robert Giegengack, former chair of Department of Earth and Environmental Science at the University of Pennsylvania, spoke out in 2007 against fears of rising CO2 impacts promoted by Gore and others. [4] “We are now producing more CO2 than all volcanoes on Earth,” van der Meer added. [20]

In this study, we compiled all the available published data from several different types of proxy to produce a continuous record of ancient CO2 levels.” [3] Humanitarian orgs should work hard to help mankind to increase the CO2 concentration? ‘CO2 is the key compound that plants need to grow – and, indirectly, that every organism needs to get the food at the end. [4]

“We cannot directly measure CO2 concentrations from millions of years ago,” says geochemist Gavin Foster from the University of Southampton in the UK. [3] During our 200,000-or-so years on this planet, CO2 concentrations have largely stayed below 300 ppm, as ice cores prove. [21] As I have measured many times, simply walking out of a Princeton lecture hall to the open air, can change the CO2 concentration from 1200 ppm in the hall to 450 ppm outside. [4] The CO2 concentrations in a corn field can change from under 300 ppm or less at noon to 600 ppm or more at midnight, depending on wind conditions. [4]

Climatologist Dr. Patrick Michaels and Chip Knappenberger declared 400 ppm of CO2 was cause for “celebration.” [4] Climate change is governed by hundreds of factors, or variables, not just CO2. [4]

“Air trapped in bubbles in polar ice cores constitutes an archive for the reconstruction of the global carbon cycle and the relation between greenhouse gases and climate in the past. [4] Since the ice has piled up over time in places like Greenland and Antarctica, scientists can drill into it to learn about the atmospheres of the past. [21] Scientists studying ice cores from Antarctica now know that the big jump in CO 2 in the atmosphere of the past century is extraordinary: in the past 800,000 years, atmospheric CO 2 has never risen this much, this fast. [41] Today, the atmosphere contains more CO 2 than at any time in at least the past 800,000 years. [41]

Despite the unprecedentedly sharp rise, that’s still significantly lower than the concentration got during Earth’s past ‘greenhouse’ periods – where it has risen as high as 3,000 ppm. [3] “We found no past time period when the drivers of climate, or climate forcing, was as high as it will be in the future if we burn all the readily available fossil fuel,” Foster explains in The Conversation. [3]

Measurements taken in 51 different countries revealed that 2016?s increase was 50 percent higher than the average of the past 10 years. [38] “Fossil fuel energy supplies about 80% of the world?s energy production–a value which has been pretty much constant for the past 40 years. [4]

“The challenge is to reconstruct what the past carbon dioxide concentration is and to utilize these geochemistry proxies the best we can essentially, how can we best interpret these records using geological archives,” said Cui. [40] Past changes in temperature do not appear to have been caused by changes in CO 2. [41] “The geologic past can provide a useful insight into our understanding of current and future environmental change,” said Cui. [40]

Since the Industrial Revolution, the carbon dioxide level has been rising and is likely to soar unless action is taken to reverse the trend, Tripati said. [39] “Certain “feedback loops? naturally control the levels of greenhouse gases in the atmosphere. [4] The overall direction of the graph is clear: CO 2 levels are increasing. [41] Former Vice President Al Gore declared the 400 ppm level “A sad milestone. [4]

“This record is the first evidence that carbon dioxide may be linked with environmental changes, such as changes in the terrestrial ecosystem, distribution of ice, sea level and monsoon intensity.” [39] A study published in 2015 found that if humanity turned its back on renewable energy and proceeded to burn through all the remaining fossil fuel resources on Earth, Antarctica would effectively melt, causing sea levels to rise by up to 60 metres. [3] Back then, the temperature was 3C (5.4F) warmer and sea level was up to 20 meters (66 feet) higher. [38] “The rate of spreading plates dictates the height of mountains, the amount and location of ores, sea level and the magnetic field of the planet,” he said. [20]

Greenhouse operators change CO2 concentrations from ambient, say 400 ppm, to 2000 ppm in 15 minutes — with absolutely no ill effects to the plants. [4] Humanitarian orgs should work hard to help mankind to increase the CO2 concentration,” Motl wrote. [4] During eras of low CO2 concentration, leaves contained high numbers of pores, called stomata, to improve gas exchange with the environment. [21]

Three years later, for the first time since scientists had begun to record them, carbon levels remained above 400 parts per million for an entire month. [22] Carbon levels usually reach an annual low point near the end of September, Scripps notes, but this year, those numbers are hovering around 401 parts per million. [22] Atmospheric carbon levels are probably stuck at 400 parts per million, scientists say. [22] Atmospheric CO 2 levels rose 40 percent between 1750 and 2011. (In 2013, atmospheric CO 2 levels surpassed 400 million parts per million for the first time in human history.) [42] According to data from the National Oceanic and Atmospheric Administration, in the 650,000 years leading up the industrial revolution, carbon dioxide levels remained below 280 parts per million (ppm). [43] The added gas was not much compared with the volume of CO 2 already in the atmosphere the CO 2 released from the burning of coal in the year 1896 would raise the level by scarcely a thousandth part. [25] Level of CO 2 in the atmosphere, 1958-2013 The curve has been climbing exponentially, much faster now than in the 1960s; despite some attempts to slow down emissions, the quantity of gas added to the atmosphere is doubling every 30-35 years. [25]

Over hundreds of millions of years, a doubled level of the gas had always gone along with a temperature rise of three degrees, give or take a degree. [25] As the gas level rose, temperature would rise with a time lag although only a few decades, not centuries, for the rates of change were now enormously faster than the orbital shifts that brought ice ages. [25] The most well-known of these studies, published in Nature, argued that if the emissions rate was not reduced, the atmospheric concentration of CFCs would likely increase 10 to 30 times the present level, with serious implications for the integrity of the ozone layer. [43] In 1938, G.S. Callendar argued that the level of carbon dioxide was climbing and raising global temperature, but most scientists found his arguments implausible. [25] It has also been altered to reflect that most scientists say the carbon levels at 400 parts per million are a “milestone,” not a “tipping point.” [22] The CO 2 levels in their record got as low as 180 parts per million in the cold periods and reached 280 in the warm periods, never higher. [25] In 1896 Arrhenius completed a laborious numerical computation which suggested that cutting the amount of CO 2 in the atmosphere by half could lower the temperature in Europe some 4-5C (roughly 7-9F) that is, to an ice age level. [25]

He figured that if industry continued to burn fuel at the current (1896) rate, it would take perhaps three thousand years for the CO 2 level to rise so high. [25] Billions of years ago the oceans would have been permanently frozen, if not for high CO 2 levels. [25] There would eventually be so much CO 2 in the ocean surface waters that the oceans would not be able to absorb additional gas as rapidly as at present. (45) Keeling kept refining and improving his measurements of the CO 2 level in the atmosphere to extract more information. [25] How, they wondered, is the gas stored and released as it cycles through the Earth’s reservoirs of sea water and minerals, and also through living matter like forests? Chamberlin was emphatic that the level of CO 2 in the atmosphere did not necessarily stay the same over the long term. [25] Why focus on that rare gas rather than water vapor, which was far more abundant? Because the level of water vapor in the atmosphere fluctuated daily, whereas the level of CO 2 was set over a geological timescale by emissions from volcanoes. [25] Even with a steady level of human emissions CO 2 would continue to accumulate rapidly in the atmosphere. [25]

The concentration of carbon dioxide in the atmosphere surged in 2016 to its highest level in 800,000 years, according to a report released Monday by the United Nation’s World Meteorological Organization (WMO). [23] The team’s deep-time reconstruction reveals previously unknown fluctuations of atmospheric carbon dioxide at levels projected for the 21st century and highlights the potential impact the loss of tropical forests can have on climate. [24] There were many ways temperature or other climate features could influence the carbon dioxide level one way or another. [25] “Most of our estimates for future carbon dioxide levels and climate do not fully take into consideration the various feedbacks involving forests, so current projections likely underestimate the magnitude of carbon dioxide flux to the atmosphere.” [24] Like Tyndall, Arrhenius largely rejected the idea that manmade emissions would grow fast enough to translate to higher atmospheric carbon dioxide levels. [43] The Clean Air Act created National Ambient Air Quality Standards, which were the first set of federal regulations restricting carbon dioxide emission levels. [43] It turned out that the 21st-century level of emissions was so massive that it was transforming the entire global carbon system into a new state. [25] Drill, baby, drill: The opening of Texas and Persian Gulf oil fields inaugurates an era of cheap energy, with global crude oil production levels going up nearly every year since. [43] In 1960, with only two full years of Antarctic data in hand, Keeling reported that this baseline level had risen. [25]

Unpredictable, so we should not change the current state which is a small CO2 increase per year, if we do change – by reducing CO2 output – it will have a chaotic result (like 2000 parts a million CO2 or 50). [24] Unless the international community makes massive strides towards the Paris Agreement goals, atmospheric CO2 could rise to 560 ppm by 2050 double the concentration in 1958, and a sign of much more global warming to come. [5] Using tighter constraints based on historical observations of warming, they conclude that doubling atmospheric CO2 would push temperatures between 2.2-3.4 C higher, with a 2% chance that ECS exceeds 4 C and a 3% chance that ECS is lower than 1.5 C. The extremes (both good and bad) of global warming thus appear less likely. [5] It can help predict how much warming will come from increases in atmospheric CO2, even before the climate settles into equilibrium. [5] The WMO said that part of the reason for the rapid rise was the El Nino climate event, which triggered droughts inhibiting the ability of plants to absorb as much CO2 as usual. [23] “Without rapid cuts in CO2 and other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement,” said World Meteorological Organization chief Petteri Taalas, according to a report from The Guardian. [44] This concept simplifies Earth?s actual climate CO2 won?t double instantly and it often takes decades or centuries for the climate to return to equilibrium but ECS is critical for gauging the planet?s response to fossil fuel emissions. [5]

They can’t spot quick spikes in CO2, say over 80 years, and the further back you go, the less sensitive it becomes. [24] How does carbon dioxide compare to other climate drivers? Carbon dioxide (CO2), more than any other climate driver, has contributed the most to climate change between 1750 and 2011. [42] This time, experts believe we’re stuck here for good, due to the cyclical effects of Mauna Loa’s CO2 curve. [22] Nasa: Ice-Core data adjusted for global mean; NOAA ESRL DATA: monthly mean CO2. [43] CO2 spikes above 400 ppm near the start of every interglacial. [24] The planet’s oceans are constantly absorbing excess CO2, causing their pH to decrease, literally acidifying the water. [22]

Some scientists took up the old argument that fertilization of plant life by additional CO 2, together with uptake by the oceans, would keep the level of gas from rising too sharply. [25] Through all these discoveries and controversies, Keeling and his colleagues had kept on quietly monitoring and analyzing the ongoing changes in atmospheric CO 2 levels. [25] With painstaking series of measurements in the pristine air of Antarctica and high atop the Mauna Loa volcano in Hawaii, he nailed down precisely a stable baseline level of CO 2 in the atmosphere. [25] In a milestone 1977 U.S. National Academy of Sciences report, Keeling and a colleague had reported that the decline of the level of CO 2 in the atmosphere would take centuries. [25] In the early 1960s, C.D. Keeling measured the level of carbon dioxide in the atmosphere: it was rising fast. [25] Burn, baby, burn: The industrial revolution spurs unprecedented levels of agricultural and industrial production, initiating the relentless release of carbon dioxide into the atmosphere. [43] They found that the gas plays a crucial role in climate change, so that the rising level could gravely affect our future. (This essay covers only developments relating directly to carbon dioxide, with a separate essay for Other Greenhouse Gases. [25] No model that could simulate the Earth’s climate — and some of the simulations had become very good indeed — failed to show warming if its greenhouse gas level was raised. [25] Or, more ominously, how a change in the gas level initiated by humanity might be amplified through a temperature feedback loop. The ancient ice ages were the reverse of our current situation, where humanity was initiating the change by adding greenhouse gases. [25] Several kinds of chemical studies of ancient rocks and soils helped pin down how the level of the gas had swung widely over geological ages, and the temperature too. [25]

The last time there was a major El Ni event, in 1998, levels only rose by 2.7 ppm. [44] Environmental factors only tell a part of the story; human activity, too, is causing these levels to rise. [44] Studies of plant species that had changed little since the rise of the dinosaurs (magnolia for one) showed that if you exposed them to a higher level of CO 2, the structure of their leaves changed. [25] The level of CO 2 acted as a regulator of water vapor, and ultimately determined the planet?s long-term equilibrium temperature. (Again, for fuller discussion follow the link at right.) [25] The new understanding was incorporated in the IPCC’s 2014 report, which warned, “Surface temperatures will remain approximately constant at elevated levels for many centuries after a complete cessation of anthropogenic CO 2 emissions.” [25]

All countries who adopt the agreement are bound to prevent global average temperatures from rising beyond 1.5C above pre-industrial levels. [22] It’s unlikely that we’ll meet the target of restricting global warming to a 2 degree C rise above pre-industrial levels; it could even reach 3 degrees C. [44] The crucial fact was that a slight warming would cause the level of greenhouse gases to rise slightly. [25] Canadian physicist Gilbert Plass warns that the warming caused by increased carbon dioxide levels will likely result in negative consequences for the planet. [43] President Obama unveils the final version of the Clean Power Plan, which aims to reduce U.S. carbon dioxide emissions by 32.0% from 2005 levels by 2030. [43] British engineer Guy Callendar links rising carbon dioxide levels to observable climate change. [43] The Paris Agreement –an international convention dedicated to fighting climate change and its effects–has laid out some firm goals directly tied to carbon levels. [22] In December, 196 countries come together at the Paris Climate Change Conference to sign the Paris Agreement, which pledges to limit rising temperatures “well below 2 degrees Celsius above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees Celsius.” [43] This gave a prediction that the concentration in the air would level off after a few centuries, with an increase of no more than 40%. [25] Meanwhile the level of CO 2 in the air kept rising, indeed faster than anyone had expected. [25] Once meteorologists understood that ocean uptake was slow, they found it possible that CO 2 levels had been rising, just as Callendar insisted. (35) Yet it was only a possibility, for the measurements were all dubious. [25]

By 1979 the ever more powerful computers had confirmed that it was impossible to construct a model that could mimick the current climate and that did not warm up a few degrees if the level of the gas was doubled. [25] That was just when greenhouse gas levels reached a level high enough to be important. [25] The President?s Science Advisory Committee publishes a study that warns of the dangers of rising carbon dioxide levels. [43] The National Academy of Sciences (NAS) releases a report on the dangers of rising carbon dioxide levels. [43] Members of Congress are shown a film produced by the fossil fuel industry, which demonstrates that increased carbon dioxide levels will be beneficial for the planet. [43] The report, entitled “Restoring the Quality of Our Environment,” warns that increased atmospheric concentrations of carbon dioxide could result in the melting of the Antarctic ice cap, rising sea levels, warming of ocean waters, and increased acidity of fresh waters. [43] The last time Earth experienced both ice sheets and carbon dioxide levels within the range predicted for this century was a period of major sea level rise, melting ice sheets and upheaval of tropical forests. [24] The resulting report from the DOE and JASON entitled “The Long Term Impact of Atmospheric Carbon Dioxide on Climate,” concluded that increased carbon dioxide levels could lead to food scarcity and rising sea levels, seriously threatening the global population. [43] By 2100, climate models predict global temperatures will be on average 4C warmer and sea levels will be 0.7m higher under “business as usual” conditions. [5] Scientists theorize that even if we prevent global average temperatures from rising above 2C, earlier sea level changes could be irreversible. [22]

Group after group cut samples from cores of ice in hopes of measuring the level. [25] Current levels have not been matched in over three million years. [44] Going beyond this qualitative result, Plass calculated that doubling the level would bring a 3-4C rise. [25] Strikingly, while the report details the possible consequences of burning fossil fuels, it does not recommend reducing emission levels. [43] Although the United States signs on, a Bush policy advisor wrote, “there is nothing in any of the language which constitutes a commitment to any specific level of emissions at any time.” [43] Congress rejects President Clinton?s proposed energy tax, opting to tax gasoline instead, which does little to reduce emission levels. [43]

Last year’s increase was 50% greater than the average yearly increase over the past decade, despite the fact that human-driven emissions of carbon dioxide have remained consistent for the few years. [23] Over the past million years, atmospheric carbon dioxide has been generally low and fluctuated predictably within a window of 200 to 300 ppm. [24] Similarly to how oceans have served as the primary carbon sink in the recent past, tropical forests 300 million years ago stored massive amounts of carbon dioxide during these ancient glacial periods. [24] Scientists can compare the amount of carbon dioxide in the atmosphere today with the amount of carbon dioxide trapped in ancient ice cores, which show that the atmosphere had less carbon dioxide in the past. [26]

The rise can be attributed in part to the recent El Ni event, but the figures from the past several years reveal that this isn’t the only factor. [44] He concluded that over the past hundred years the concentration of the gas had increased by about 10%. [25] Despite this minor discrepancy, both agencies agree that the 2017 data make the past four years the hottest period in their 138-year archives. [5] The graphs included in this timeline serve to show how the Earth has changed over the past 200 years. [43] The past 70 years have been good for corn production in the midwestern United States, with yields increasing fivefold since the 1940s. [24] With this in mind, we?ve created a climate change timeline highlighting the evolution of science, the intrusion of denial, and the sluggishness of policy over the past 200 years. [43]

Breecker et al. (2010) offer new evidence on fossil soil chemistry showing that “past greenhouse climates were accompanied by concentrations similar to those projected for A.D. 2100”. [25] The annual increase over the past decade has been just 2.08 ppm. [44] An expert on steam technology, Callendar apparently took up meteorology as a hobby to fill his spare time. (14) Many people, looking at weather stories from the past, had been saying that a warming trend was underway. [25] In 1955, the chemist Hans Suess reported an analysis of wood from trees grown over the past century, finding that the newer the wood, the higher its ratio of plain carbon to carbon-14. [25] When it comes to climate change, repeating the past is a luxury we can?t afford. [43]

Top: Detail of atmospheric CO2 concentration (ppm) between 800,000 years ago – 2017. [42] Bottom: Atmospheric CO2 concentration over the last 65 million years in parts per million (ppm). [42]

The forth IPCC report states that the “warming of the climate system is unequivocal,” and will very likely carry negative consequences for the planet, including: food scarcity, water stress, sea level rise, flooding, loss of biodiversity, drought, and increased intensity of extreme weather. [43] We added that thermal expansion is another cause of sea level rise, and corrected the implication that ocean acidification was a cause of coral bleaching. [22] By 2100, approximately 13 million people in the U.S. are projected to lose their homes due to rising sea levels. [22] The sea level was rising while mountain glaciers, the Greenland and Antarctic ice sheets, and Arctic sea ice melted back, all at accelerating rates. [25] In the near future, humans, among other species, will be catastrophically affected by sea level changes. [22] INTERACTIVE MAP: Explore the hundreds of U.S. coastal communities that will face chronic inundation and possible retreat as sea levels rise. [42] The Earth had been virtually a different planet, with tropical forests near the poles and sea levels a hundred meters higher. [25] The “distress of nations in perplexity because of the roaring of the sea and the waves” of Luke 21:25 describes climate change well, with rising sea levels and weather extremes, although he may be referring to tsunamis, or both. [24]

RANKED SELECTED SOURCES(44 source documents arranged by frequency of occurrence in the above report)

1. (56) CO2 Nears 400 ppm – Relax! It?s Not Global Warming “End Times? But Only A “Big Yawn? Climate Depot Special Report | Climate Depot

2. (46) The Carbon Dioxide Greenhouse Effect

3. (38) How the World Passed a Carbon Threshold and Why It Matters – Yale E360

4. (23) 200 years of climate science and policy

5. (20) The Last Time CO2 Was This High, Humans Didnt Exist | Climate Central

6. (20) CO2: Past, Present, & Future Time Scavengers

7. (18) Earth’s CO2 Home Page

8. (16) Last time carbon dioxide levels were this high: 15 million years ago, scientists report | UCLA

9. (15) CO2 levels are at their highest in 800,000 years | World Economic Forum

10. (14) Down To Earth Climate Change – Resources

11. (14) Goodbye World: We?ve Passed the Carbon Tipping Point For Good – Motherboard

12. (13) What the ancient CO2 record may mean for future climate change

13. (13) As CO2 Levels Rise, Scientists Question Best- and Worst-Case Scenarios of Climate Change – Future of Life Institute

14. (12) Carbon dioxide in atmosphere exceeds 410 ppm, threatens human health – Business Insider

15. (12) If CO2 Emissions Keep Up, Earth Is Headed Back to The Triassic Period – Or Worse

16. (12) CO2 Past, Present, Future

17. (10) Dinosaur Era Had 5 Times Todays CO2

18. (8) Global warming: Carbon dioxide levels continue to soar

19. (8) CO2 set to hit levels not seen in 50 million years by 2050 | New Scientist

20. (8) When’s the Last Time Our CO2 Levels Were This High? – Pacific Standard

21. (8) Climate Change: Atmospheric Carbon Dioxide | NOAA Climate.gov

22. (7) Climate and CO2 in the Atmosphere

23. (7) Carbon Dioxide Levels on Earth Haven’t Been This High in Three Million Years – Futurism

24. (6) As CO2 Levels Soar Past Troubling 410 ppm Threshold, Trump Kills NASA Carbon Monitoring Program

25. (6) Graphic: The relentless rise of carbon dioxide – Climate Change: Vital Signs of the Planet

26. (5) Carbon dioxide levels hit ‘point of no return’

27. (5) Global Carbon Dioxide Levels Increase Yet Again | Time

28. (5) The Ups and Downs of CO2

29. (5) Why does CO2 get most of the attention when there are so many other heat-trapping gases? | Union of Concerned Scientists

30. (5) Scientists Sound the Alarm: CO2 Levels Race Past Point of No Return

31. (4) Global atmospheric CO2 levels hit record high | Environment | The Guardian

32. (4) CO2 Levels: Current & Historic Atmospheric Carbon Dioxide / Global Temperature Graph & Widget

33. (4) Climate Milestone: Earths CO2 Level Nears 400 ppm

34. (4) Carbon Dioxide Levels Grew at Record Pace in 2016 – Scientific American

35. (4) Atmospheric CO2 Levels Are Now The Highest In 800,000 Years | IFLScience

36. (3) Chart of 420,000 year history: temperature, CO2, sea level – John Englander – Sea Level Rise Expert

37. (3) What Can Carbon Dioxide Levels 50 Million Years Ago Tell Us About Climate Change Today? | CleanTechnica

38. (2) The Proof Is in the Atmosphere | A Student’s Guide to Global Climate Change | US EPA

39. (2) Report: Atmospheric CO2 levels hit all-time high in 2017

40. (2) Carbon dioxide levels race past troubling milestone | National Oceanic and Atmospheric Administration

41. (1) 23rd century CO2 levels could surpass the age of the dinosaurs

42. (1) How have levels of carbon dioxide in the atmosphere changed in the past 100 years? – Quora

43. (1) What the Ancient CO2 Record May Mean for Future Climate Change | UC Davis

44. (1) Figure 14: 800,000 Years of Temperature and Carbon Dioxide Records Climate Change at the National Academies of Sciences, Engineering, and Medicine