“Methane concentrations are not just increasing, they are increasing faster than ever,” said Rob Jackson, professor of Earth system science at Stanford University.
The study comes on the same day as a new UN report that says the world’s governments have failed to commit to sufficiently reduce carbon emissionsputting the world on track for a 2.5 degree Celsius (4.5 degree Fahrenheit) increase in global temperatures by the end of the century.
The analysis indicates that the level of emissions implied by new country commitments was slightly lower than a year ago, but would still lead to a full temperature increase beyond the target level set at the last climate summits. To avoid the most catastrophic consequences 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 severity of the threats we face and the short time we have left to avoid the devastating consequences of runaway climate change,” said Simon Stiell, Executive Secretary of the United Nations. Climate Change Secretariat. “We are still a long way from the scale and pace of required emissions reductions.”
Instead, according to the UN report, the world is heading towards a future of unbearable heat, escalating weather disasters, collapsing ecosystems and widespread famine and disease.
“It’s a grim, horrifying and incomprehensible picture,” Inger Andersen, executive director of the United Nations Environment Programme, said of the current trajectory of global warming. “This image is simply not an image that we can accept.”
The fastest way to affect the rate of global warming would be to reduce emissions of methane, the second largest contributor to climate change. Its warming impact is 80 times greater than that of carbon dioxide over a 20-year period. The WMO said the amount of methane in the atmosphere jumped 15 parts per billion in 2020 and 18 parts per billion in 2021.
Scientists are investigating whether unusually large increases in atmospheric methane levels in 2020 and 2021 are the result of “climate feedback” from natural sources such as tropical wetlands and rice paddies, or whether they are the result human-made natural gas. and industrial leaks. Or both.
Methane emitted by fossil sources contains more carbon-13 isotope than that produced by wetlands or livestock.
“The isotope data suggests that it is biological rather than fossil methane from gas leaks. It could come from agriculture,” Jackson said. He warned that “this could even be the start of a dangerous warming-induced acceleration of methane emissions from wetlands and other natural systems that have concerned us for decades.”
The WMO said that as the planet warms, organic matter breaks down faster. If organic matter decomposes in water – without oxygen – this leads to methane emissions. This process could feed on itself; if tropical wetlands become wetter and warmer, more emissions are possible.
“Will warming fuel warming in tropical wetlands? Jackson asked. “We do not know yet.”
Antoine Halff, chief analyst and co-founder of the company Kayrros, which does extensive analysis of satellite data, said “we see no increase” in methane generated from fossil sources. He said some countries, like Australia, have reduced emissions while others, like Algeria, have gotten worse.
Atmospheric levels of the other two main greenhouse gases – carbon dioxide and nitrous oxide – also reached record highs in 2021, according to the WMO study: “Rising levels of carbon dioxide carbon from 2020 to 2021 was higher than the average annual growth rate over the past decade.”
Carbon dioxide concentrations in 2021 were 415.7 parts per million (or ppm), methane at 1908 parts per billion (ppb), and nitrous oxide at 334.5 ppb. These values were respectively 149%, 262% and 124% of pre-industrial levels.
The report “underlined, once again, the enormous challenge – and the vital need – for urgent action to reduce greenhouse gas emissions and prevent global temperatures from rising even further in the future. “, said WMO Secretary-General Petteri Taalas.
Like others, Taalas urged the pursuit of low-cost techniques to capture short-lived methane, especially when it comes to natural gas. Due to its relatively short lifespan, “methane’s impact on the climate is reversible,” he said.
“The necessary changes are economically affordable and technically possible. Time is running out,” he said.
The WMO also highlighted the warming of the oceans and land as well as the atmosphere. “Of the total emissions from human activities during the period 2011-2020, approximately 48% accumulated in the atmosphere, 26% in the ocean and 29% on land,” the report said.
The WMO report comes 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 promoting the Global Methane Pledge, which has set itself the goal of achieve a 30% reduction in the atmosphere by 2030. They estimated that this could reduce the rise in temperatures that would otherwise occur by 0.2 degrees Celsius. So far, 122 countries have signed this pledge.
White House climate negotiator John F. Kerry said in the joint US-China statement released in Glasgow, China pledged to release “an ambitious plan” for this year’s climate summit. year which would aim to reduce its methane pollution. So far, however, that hasn’t happened and China has yet to issue a “nationally determined contribution” or NDC, in United Nations jargon.
“We look forward to an updated NDC 2030 from China that accelerates CO2 reductions and tackles all greenhouse gases,” Kerry 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.
Yet the United States is also among the vast majority of countries that have not updated their NDCs this year, something all countries promised to do at the end of the Glasgow summit a year ago.
Only 24 countries have submitted new pledges in the past 12 months – and few of the updated pledges represent a significant improvement on their past pledges, according to the UN report. Australia has made the most significant changes to its national climate target, which had not been previously updated since the signing of the Paris agreement in 2015.
In total, the combined 193 climate pledges made since Paris would increase emissions by 10.6% by 2030, compared to 2010 levels. This reflects a slight improvement on last year’s assessment, which revealed that countries were on track to increase their emissions by 13.7% by 2030, compared to 2010 levels, the United Nations said.
But nations must reduce their carbon emissions to around 45% of their 2010 levels to avoid warming beyond that. 1.5 degrees Celsius (2.7 degrees Fahrenheit) – a threshold at which scientists say humanity can avoid the most catastrophic effects of climate change.
Just under half of the countries also submitted long-term plans to reduce their emissions to zero. If these countries keep their promises, according to the UN report, global emissions by mid-century could be 64% lower than they are now. Scientists say these cuts could keep the temperature increase below 2 degrees Celsius (3.6 degrees Fahrenheit), bringing humanity one step closer to tolerable levels of warming.
“But it’s really not clear whether countries will actually succeed,” warned Joeri Rogelj, a climatologist at Imperial College London who specializes in the pathways of global warming.
There are huge gaps between nations’ short-term climate commitments and their long-term plans, he noted. For most countries, the emissions trajectories implied by their NDCs would make it nearly impossible to achieve a 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 robbed itself of a chance to make a slow and orderly transition to a safer and more sustainable future. Countries must constantly raise their ambitions, rather than making modest carbon reduction pledges that are updated every five years. No nation can rest easy until every country eliminates global warming emissions and restores the natural systems capable of removing carbon from the atmosphere, she said.
“We need to see more and faster,” she said. “Today you stretch and tomorrow you stretch and the day after tomorrow you stretch.”
Chris Mooney contributed to this report.