An eloquent graph, with a line descending rapidly. It shows, according to those who share it, the concentration of CO2 in the earth's atmosphere. The graph is used to argue that over the last 140 million years, CO2 levels would have been steadily declining. As we will see in detail, it is not true that “over the last 140 million years, CO2 levels have constantly declined”, on the contrary, the concentration of CO2 in the atmosphere has never been this high over the past 800,000 years.
For those in a hurry:
- A graph is published showing that the concentration of carbon dioxide in the atmosphere is the lowest in the last 140 million years.
- This graph would have been found in the study “Berner, 2001”.
- The study doesn't actually show this graph.
- 140 million years ago, the concentration of CO2 was much higher than today.
- But the current concentration is the highest in the last 800,000 years.
- It is therefore not true that “over the last 140 million years, CO2 levels have been constantly decreasing”.
- The content came from an NGO known for climate disinformation and closely linked to the oil industry.
Analyzes
Let's see a screenshot of one of the messages being checked. The description reads:
140 MILLION YEAR TREND OF DANGEROUS CO2 DECREASE
Over the past 140 million years, CO2 levels have fallen precipitously and steadily to within about 30 ppm of the 150 ppm “death line” below which plants cannot survive. Short-term data from ice cores and long-term data going back 140 million years (Berner 2001) show an alarming downward trend toward CO2 deficiency. The release of carbon dioxide from the use of fossil fuels has allowed humanity to increase concentrations of this beneficial molecule and perhaps avoid a full-blown CO2-related climate apocalypse. From the CO2 Coalition
What is the CO2 Coalition
As noted several times in the post, the content was initially broadcast by the channels of CO2 Coalition. The CO2 Coalition is an NGO established in 2015 “with the aim of educating thought leaders, policy makers and the public about the significant contribution carbon dioxide makes to our lives and the economy”, as indicated on the organization's website. The CEO of the CO2 Coalition is William O'Keefe. Man, as reconstructed by Desmogwas the head of a similar organization that was later transformed into the current one in 2015, but most importantly he is the former executive vice president and chief financial officer of the American Petroleum Institute, the leading American professional organization in the field petrochemicals and chemical engineering. , where he held these positions from 1974 to 1999.
Climate disinformation from the CO2 Coalition
The CO2 Coalition is known for publishing misleading information about climate and climate change. In 2017, it was among the organizations that signed a letter sent to former US President Donald Trump to congratulate him following the then White House leader's decision to withdraw the United States from the Accord. Paris. In the “learning” section of the NGO’s website, we discover that according to the CO2 Coalition, “real science shows that there is no climate emergency and that there are no financial risks or other climate-related problems caused by fossil fuels and CO2.
What are greenhouse gases used for?
Carbon dioxide CO2, along with methane (CH4) and nitrous oxide (N2O), are greenhouse gases and contribute to the greenhouse effect on Earth. When the sun's rays heat the earth, it radiates heat back into the atmosphere, while the greenhouse gases mentioned above trap the heat and keep the earth warm. Mainly due to the fact that today's human activities burn fossil fuels, more greenhouse gases are released into the atmosphere, making the greenhouse “blanket” thicker and the earth even more hot, causing melting ice and the climate changes we are already experiencing. life. In general, the greenhouse effect is necessary for life on earth, but the excessive thickness of the greenhouse gas layer causes climate change.
The graphic is not in the studio
It is incorrect to claim that the graph is taken from “Berner 2001”, given that by consulting the study (Geocarb III: A revised model of atmospheric CO2 during the Phanerozoic) you see that in reality the graph is not there. That said, it is true to argue that hundreds of millions of years ago, the concentration of carbon dioxide in the atmosphere was much higher than today. In January 2024, according to data provided by NASA, the concentration of CO2 was 423 parts per million, compared to the pre-industrial era, when the concentration of CO2 was just below 280 parts per million. Now that we have the right context, let's see why it isn't true that “CO2 levels have been steadily declining over the past 140 million years.”
It is not true that “over the last 140 million years, CO2 levels have steadily declined”
The maximum concentration probably occurred – there are no measurements from the time but only reconstructions – during the Cambrian period, hundreds of millions of years ago at 6,000 ppm, as l 'explains RA Eggleton, in A brief introduction to climate change. Since then, levels have fluctuated until they fell to values similar to current ones around 300 million years ago, again according to Berner, 2001. They reached a new peak, almost 10 times current concentrations, then began to decline steadily. again about 140 million years ago. Since then, they have started to increase again, mainly due to human activities. In fact, as NASA reports, current concentrations are the highest in the last 800,000 years. It is therefore not true that “over the last 140 million years, CO2 levels have steadily declined”.
Conclusions
A graph is published showing that the concentration of carbon dioxide in the atmosphere is the lowest in the last 140 million years. This graph would have been found in the study “Berner, 2001”. In reality, the study doesn't show the graph. 140 million years ago, the concentration of CO2 was much higher than today. But the current concentration is the highest in the last 800,000 years. It is therefore not true that “over the last 140 million years, CO2 levels have been constantly decreasing”. The content came from an NGO known for climate disinformation and closely linked to the oil industry.
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