“Methane concentrations are not only increasing, they are increasing faster than ever,” said Rob Jackson, a professor of Earth system sciences at Stanford University.
The study comes as a new UN report says the world’s governments have not committed to reducing carbon emissions enough, putting the world on track for a 2.5°C (4.5°F) increase in global temperatures by the end of the year. . century
Emissions from the new commitments are slightly lower than a year ago, the analysis said, but would still lead to an overall increase in temperatures beyond the target level set at the latest climate summits. To avoid the most catastrophic consequences of climate change, humanity must limit warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels, scientists say.
“Government decisions and actions must reflect the level of urgency, the severity of the threats we face, and the short time we have to avoid the devastating consequences of runaway climate change,” said UN Executive Secretary Simon Steele. Secretariat of Climate Change We are still not close to the scale and speed of reducing greenhouse gas emissions needed.
Instead, the UN report shows that the world is headed for a future of sweltering heat, increasing weather disasters, ecosystem collapse and widespread hunger and disease.
Inger Andersen, executive director of the United Nations Environment Programme, said of the current global warming trajectory: “It is a grim, terrifying and incomprehensible picture. “This picture is not just an image that we can accept.”
The fastest way to affect the rate of global warming is to reduce methane emissions, the second largest driver of climate change. Its warming effect is 80 times greater than that of carbon dioxide over a 20-year period. Methane levels in the atmosphere increased by 15 parts per billion in 2020 and 18 parts per billion in 2021, the WMO said.
Scientists are investigating whether unusually large increases in atmospheric methane levels in 2020 and 2021 are due to “climate feedback” from nature-based sources such as tropical wetlands and rice paddies, or whether the increases are the result of man-made natural gas. and industrial spills or both.
Methane emitted from fossil sources has more carbon-13 isotope than that produced from wetlands or cows.
“Isotopic data suggest that the methane is biological rather than fossil methane from the gas leak. Jackson said it could be from agriculture. “It could even be the start of a dangerous warming-driven acceleration in methane emissions from wetlands and other natural systems that we’ve worried about for decades,” he warned.
As the planet warms, organic matter breaks down faster, the WMO said. If organic matter decomposes in water – without oxygen – it results in methane emissions. This process can feed on itself. If tropical wetlands become wetter and warmer, more greenhouse gas emissions are possible.
“Does warming feed warming in tropical wetlands?” Jackson asked. “We don’t know yet.”
“We’re not seeing any increase” in methane produced by fossil sources, said Antoine Halff, senior analyst and co-founder of Kayrros, which conducts extensive analysis of satellite data. Some countries, such as Australia, have reduced emissions while others, such as Algeria, have worsened, he said.
According to the WMO study, atmospheric levels of two other major greenhouse gases – carbon dioxide and nitrogen oxide – also peaked in 2021: “The increase in carbon dioxide levels from 2020 to 2021 is greater than the average annual growth rate over the past. was. decade.”
Carbon dioxide concentrations in 2021 were 415.7 parts per million (or ppm), methane at 1,908 parts per billion (ppb), and nitrogen oxides at 334.5 ppb. These values show 149%, 262% and 124% of the pre-industrial levels, respectively.
WMO Secretary-General Petri Talas said the report once again underscored the enormous challenge – and the critical need – for urgent action to reduce greenhouse gas emissions and prevent further increases in global temperatures in the future.
Like others, Taalas wants to pursue low-cost techniques for short-term methane capture, especially when it comes to natural gas. Because of its relatively short lifespan, methane’s “impact on climate is reversible,” he said.
The required changes are economically viable and technically feasible. Time is running out.”
The WMO also noted the warming of the oceans and land as well as the atmosphere. It is stated in this report: Of the total emissions caused by human activities during the period of 2011-2020, about 48% were accumulated in the atmosphere, 26% in the ocean and 29% on land.
The WMO report was released shortly before the COP27 climate conference in Egypt next month. Last year, ahead of the climate conference in Glasgow, Scotland, the United States and the European Union took the lead in a global methane pledge aimed at achieving a 30 percent reduction in the atmosphere by 2030. It is estimated that it could reduce 0.2 degrees Celsius of the temperature increase that would otherwise occur. So far, 122 countries have signed up for this commitment.
John F. Kerry, the White House climate negotiator, said that in a joint U.S.-China statement issued in Glasgow, China pledged to release “an ambitious plan” for this year’s climate summit to reduce its methane pollution. he does. However, so far this has not happened and China has yet to issue an updated “Nationally Determined Contribution” or NDC in UN parlance.
“We look forward to an updated 2030 NDC from China that accelerates CO2 reductions and addresses all greenhouse gases,” Carey said.
“To keep this goal alive, national governments must strengthen their climate action plans now and implement them over the next eight years,” he said.
However, the United States is also among the vast majority of countries that have not updated their NDCs this year, which all countries promised to do at the end of the Glasgow meeting a year ago.
The UN report shows that only 24 countries have made new pledges in the past 12 months – and few of the updated pledges represent a meaningful improvement over their past pledges. Australia made the most significant changes to its national climate target, which has not been updated since the signing of the Paris Agreement in 2015.
A postcard from the future of our climate
Taken together, the total of 193 climate commitments made since Paris would increase greenhouse gas emissions by 10.6 percent by 2030 compared to 2010 levels. The UN said this represented a slight improvement from last year’s assessment, which showed countries were on track to increase emissions by 13.7 percent by 2030 compared to 2010 levels.
But countries must cut their carbon output to about 45 percent of their 2010 levels to avoid warming of more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) — the threshold at which scientists say humanity can avoid the most catastrophic effects of climate change. and prevent air
Less than half of the countries have presented long-term plans to reduce their greenhouse gas emissions to zero. A UN report shows that if these countries keep their promises, global emissions of greenhouse gases could be 64% lower by mid-century than they are now. Scientists say this reduction could keep temperature increases below 2 degrees Celsius (3.6 degrees Fahrenheit), bringing humanity somewhat closer to tolerable levels of warming.
“But it’s not really clear whether countries will actually do it,” warned Jory Rogel, a climate scientist at Imperial College London who specializes in global warming trajectories.
He pointed out that there are many differences between countries’ short-term climate commitments and their long-term plans. For many countries, the emission trajectories outlined by their NDCs make it nearly impossible to achieve the net zero goal by mid-century.
Andersen said the UN’s findings underscore a simple, disturbing fact: By waiting too long to act on climate change, humanity has denied itself the opportunity to make a smooth and orderly transition to a safer, more sustainable future. Countries need to continually raise their ambitions, rather than making diminutive carbon reduction commitments that are updated every five years. No country can rest easy, he said, until every country eliminates planet-warming greenhouse gas emissions and restores natural systems that can pull carbon out of the atmosphere.
“We need to see more and faster,” he said. “Today you stretch and tomorrow you stretch and the day after that you stretch.”
Chris Mooney contributed to this report.
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