“Methane concentrations are not only increasing, they are increasing faster than ever before,” said Rob Jackson, a professor of Earth system science at Stanford University.
The study comes on the same day as a new UN report which says the world’s governments have not committed to reducing carbon emissions enough to lead to a 2010 target. By the end of the year, global temperatures will rise by 2.5 degrees Celsius (4.5 degrees Fahrenheit). century.
The analysis said the emission levels under the new commitments by countries were slightly lower than a year ago, but would still lead to a full increase in temperatures above the target level set at the last climate summits. To avoid the most catastrophic effects of climate change, scientists say humanity must limit warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels.
“Government decisions and actions must reflect the level of urgency, the seriousness of the threats we face and the short time we have to avoid the devastating effects of runaway climate change,” said UN Executive Secretary Simon Stiell. Climate Change Secretariat. “We are still nowhere near the scale and pace of emissions reductions needed.”
Instead, the UN report found that the world is headed for unbearable heat, increasing weather disasters, collapsing ecosystems and widespread hunger and disease.
“It’s a bleak, terrifying, incomprehensible picture,” Inger Andersen, executive director of the UN Environment Program, said of the current path of global warming. “That picture is just not one we can accept.”
The fastest way to affect the rate of global warming would be to reduce emissions of methane, the second largest driver of climate change. It has 80 times the warming effect of carbon dioxide over 20 years. The WMO said the amount of methane in the atmosphere increased by 15 parts per billion in 2020 and by 18 parts per billion in 2021.
Scientists are investigating whether an unusually large increase in methane levels in the atmosphere in 2020 and 2021 is the result of “climate change” from natural sources such as tropical wetlands and rice paddies, or is the result of man-made natural gas. and industrial runoff. Or both.
Methane emitted by fossil sources has more of the isotope carbon-13 than that produced from wetlands or cattle.
“The isotope data shows that it is biological rather than fossil methane from a gas leak. It could be from agriculture,” Jackson said. He warned that “it could even be the beginning of dangerous warming-induced releases of methane from wetlands and other natural systems that we’ve been worried about for decades.”
As the planet warms, organic matter breaks down faster, the WMO said. If organic matter decomposes in water, without oxygen, methane is released. This process could feed on itself; if tropical wetlands become wetter and warmer, there could be more emissions.
“Will warming drive warming in tropical wetlands?” Jackson asked. “We don’t know yet.”
Antoine Halff, chief analyst and co-founder of Kayrros, a company that performs detailed analysis of satellite data, said “we don’t see any increase in methane” from fossil sources. He said some countries, such as Australia, have reduced emissions, while others, such as Algeria, have seen it worsen.
Atmospheric levels of the other two main greenhouse gases, carbon dioxide and nitrous oxide, also reached record highs in 2021, the WMO study said: “The increase in carbon dioxide between 2020 and 2021 was higher than the average annual growth rate during the recent period. decade.”
Carbon dioxide concentration in 2021 was 415.7 ppm (or ppm), methane 1908 ppm, and nitrous oxide 334.5 ppb. These values were 149, 262, and 124 percent of pre-industrial levels, respectively.
The report “re-emphasizes the enormous challenge – and the vital need – to take urgent action to reduce greenhouse gas emissions and prevent future global temperature increases,” said WMO Secretary-General Petteri Taal.
Like others, Taal called for low-cost methods to capture short-lived methane, especially when it comes to natural gas. Because of methane’s relatively short lifetime, “the impact on climate is reversible,” he said.
“The necessary changes are economically available and technically feasible. Time is running out,” he said.
The WMO also noted the warming of the oceans and land and the atmosphere. “About 48 percent of all human emissions in 2011-2020 accumulated in the atmosphere, 26 percent. – in the ocean and 29 percent. – on land,” the report states.
The WMO report comes just ahead of next month’s COP27 climate conference in Egypt. Last year, in preparation for the climate conference in Glasgow, Scotland, the United States and the European Union took the initiative to promote the Global Methane Pledge, which set a target of 2030. reduce the atmosphere by 30 percent. It is estimated that this could shave 0.2 degrees Celsius off the temperature rise that would otherwise occur. To date, 122 countries have signed this pledge.
White House climate negotiator John F. Kerry said that in a joint U.S.-China declaration in Glasgow, China promised to release an “ambitious plan” for this year’s climate summit to reduce methane emissions. But so far that hasn’t happened, and China still hasn’t provided its latest “nationally determined contribution,” or NDC, in United Nations parlance.
“We are looking forward to the updated 2030 An NDC from China that will accelerate CO2 reductions and eliminate all greenhouse gases,” Kerry said.
“To keep this goal alive, national governments need to strengthen their climate action plans now and implement them over the next eight years,” he said.
But the United States is also among the majority of countries that have not updated their NDCs this year, something all countries promised to do when the Glasgow summit ended a year ago.
The UN report said only 24 countries had made new pledges in the past 12 months, and only a handful of renewed pledges represented a significant improvement over previous pledges. Australia has made the most significant changes to its national climate target, which has not previously been updated since the Paris Agreement was signed in 2015.
Postcards from our climate future
A total of 193 climate change commitments made since Paris until 2030. will increase by 10.6 percent compared to 2010. This represents a slight improvement on last year’s assessment, which found that countries would have intends to increase emissions by 13.7 percent compared to 2010. level, the United Nations reported.
However, countries must reduce their carbon emissions to around 45 percent by 2010. level to avoid warming of more than 1.5 degrees Celsius (2.7 degrees Fahrenheit), the threshold that scientists say can prevent humanity from experiencing the most catastrophic effects of climate change.
Just under half of the countries have also submitted long-term plans to reduce their emissions to zero. If these countries follow through on their pledges, the UN report found that global emissions could be 64 percent lower by mid-century than they are now. Scientists say these cuts could keep temperatures below 2 degrees Celsius (3.6 degrees Fahrenheit), bringing humanity closer to a tolerable level of warming.
“But it’s not really clear that countries will actually do that,” warned Joeri Rogelj, a climate scientist at Imperial College London who specializes in global warming pathways.
He noted that there are huge discrepancies between countries’ short-term climate change commitments and their long-term plans. For most countries, the emission trajectories projected by their NDCs make it almost impossible to reach the net zero goal by mid-century.
The UN findings underscore a simple, sobering fact, Andersen said: By waiting so long to act on climate change, humanity has given up the opportunity to move slowly and orderly toward a safer, more sustainable future. Instead of making modest carbon reduction commitments that are renewed every five years, countries need to continually raise their ambitions. No nation can be at peace until every country eliminates planet-warming pollutants and restores natural systems capable of removing carbon dioxide from the atmosphere, she said.
“We need to see more and faster,” she said. “You stretch today, you stretch tomorrow, and the day after that.”
Chris Mooney contributed to this report.
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