“Methane concentrations are not only rising, they’re rising faster than ever,” said Rob Jackson, a professor of Earth system science at Stanford University.
The study comes on the same day as a new UN report that says world governments have not committed to reducing carbon emissions needed, leading to a 2.5 degree Celsius (4.5 degree Fahrenheit) rise in global temperatures. century
While the level of emissions implied by countries’ new commitments is slightly lower than a year ago, the analysis said it would result in an outright temperature increase beyond the target levels set at the most recent climate summits. To avoid the most devastating consequences of climate change, scientists say, humanity must limit warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial times.
“Government decisions and actions must reflect the urgency, the gravity of the threats we face, and the short amount of time left to avoid the catastrophic effects of climate change,” said UN Executive Secretary Simon Steele. Climate Change Secretariat. “We’re still nowhere near the scale and pace of emissions reductions that are needed.”
Instead, the UN report found, the world is barreling toward a future of unbearable heat, increasing climate disasters, crumbling ecosystems, and widespread hunger and disease.
“It’s a bleak, terrifying, incomprehensible picture,” Inger Andersen, executive director of the UN Environment Programme, said of the world’s current warming trajectory. “That picture is not one we can accept.”
The fastest way to affect the pace of global warming is to reduce methane emissions, the second largest contributor to climate change. It causes 80 times more warming than carbon dioxide over a 20-year period. Atmospheric methane levels have increased by 15 parts per billion in 2020 and 18 parts per billion in 2021, the WMO said.
Scientists are studying whether the unusual increase in atmospheric methane levels in 2020 and 2021 is the result of “climate feedback” from nature-based sources such as tropical wetlands and rice paddies or human-made natural gas emissions. and industrial spills. or both.
Methane emitted by fossil sources has more of the carbon-13 isotope than that produced by wetlands or livestock.
“The isotope data suggest that the fossil methane from the gas leak is more organic than that from agriculture,” Jackson said. “This could be the beginning of a dangerous warming-induced acceleration that we’ve been worried about for decades in methane emissions from wetlands and other natural systems,” Jackson said.
As the planet warms, organic matter is breaking down faster, the WMO said. Without oxygen – when organic matter decomposes in water – this leads to methane emissions. This process will feed on itself; If tropical wetlands become wetter and warmer, more emissions are possible.
“Does warm food heat up in tropical wetlands?” Jackson asked. “We don’t know yet.”
Antoine Hoff, chief analyst and co-founder of Kairos, a firm that conducts extensive analysis of satellite data, said “we see no increase” in methane produced by fossil sources. Some countries, such as Australia, have cut emissions while others such as Algeria have worsened, he said.
Atmospheric levels of two other major greenhouse gases, carbon dioxide and nitrous oxide, reached record highs in 2021, the WMO study said: “Carbon dioxide levels from 2020 to 2021 are larger than last year’s average annual growth rate. decade.”
In 2021, carbon dioxide concentrations were 415.7 parts per million (or ppm), methane 1908 parts per billion (ppb), and nitrous oxide 334.5 ppb. These values represent 149 percent, 262 percent, and 124 percent, respectively, of pre-industrial levels.
“The report underscores the great challenge and the urgent need for urgent action to reduce greenhouse gas emissions and prevent further increases in global temperatures in the future,” said WMO Secretary-General Petri Thales.
Like others, Thales has been motivated to pursue low-cost technologies for short-term methane capture, particularly in the case of natural gas. Because of its relatively short lifespan, methane’s “climate impact is irreversible,” he said.
“The necessary changes are financially affordable and technically feasible. Time is running out,” he said.
The WMO also pointed to warming oceans, land and atmosphere. According to the report, 48 percent of the total emissions from human activities during 2011-2020 accumulated in the atmosphere, 26 percent in the ocean and 29 percent on land.
The WMO report comes ahead of the COP27 climate conference in Egypt next month. Last year, ahead of a climate conference in Glasgow, Scotland, the United States and the European Union led efforts to promote a global methane pledge aimed at reducing atmospheric emissions by 30 percent by 2030. A reduction of 0.2°C is estimated. So far, 122 countries have signed the pledge.
In a joint US-China announcement in Glasgow, China pledged to release an “ambitious plan” to reduce methane emissions at this year’s climate summit, according to White House climate negotiator John F. Kerry said. So far, however, that hasn’t happened, and China still hasn’t provided an up-to-date “nationally determined contribution,” or NDC, in United Nations parlance.
“We look forward to an updated 2030 NDC that accelerates CO2 reductions from China and addresses 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 among the vast majority of countries that have not updated their NDCs this year, as all countries promised to do so at the end of the Glasgow summit a year ago.
Only 24 countries submitted new pledges in the past 12 months – and some of the updated commitments represent a meaningful improvement over their previous pledges, the UN report found. Australia has made the most significant changes to its national climate target, which has not been updated since the signing of the Paris Agreement in 2015.
Postcards from our climate future
Overall, the 193 climate pledges made since Paris call for a 10.6 percent increase by 2030 compared to 2010 levels. This reflects a slight improvement from last year’s assessment, which found that countries are on track to increase emissions by 13.7 percent by 2030 compared with 2010 levels, the United Nations said.
But to avoid warming beyond 1.5 degrees Celsius (2.7 degrees Fahrenheit), nations must cut their carbon output to 45 percent of 2010 levels — scientists say, so humanity can avoid the most devastating effects of climate change.
Less than half of countries have submitted long-term plans to bring their emissions to zero. If these countries keep their pledges, global emissions could be 64 percent lower by mid-century than they are now, the UN report found. Scientists say these cuts could keep temperatures below 2 degrees Celsius (3.6 degrees Fahrenheit), bringing humanity closer to tolerable warming levels.
“But it’s not really clear whether countries will pull it off,” warned Jory Rogelge, a climate scientist at Imperial College London who specializes in global warming trajectories.
He pointed out that there are huge discrepancies between nations’ recent climate pledges and their long-term plans. For most countries, the emissions trajectories implied by their NDCs will make it nearly impossible to achieve the net-zero goal by mid-century.
The UN findings underscore a simple fact, Anderson said: By waiting so long to act on climate change, humanity has denied itself the opportunity to make a slow and orderly transition to a safer, more sustainable future. Instead of making modest carbon-cutting pledges that are updated every five years, countries should continually strengthen their ambitions. No country can rest until every country eliminates planet-warming emissions and restores natural systems that can pull carbon out of the atmosphere, she said.
“We need to see more quickly,” she said. “Today you stretch, tomorrow you stretch, the day after you pull.”
Chris Mooney contributed to this report.
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