UN publishes dazzling assessment of the state of climate change
Climate change has been altering the Earth in “unprecedented” ways for thousands of years – and in some cases, hundreds of thousands of years – according to a dazzling report released by the United Nations on Monday.
The sobering assessment also found that some of the changes that are already happening, such as warming oceans and rising sea levels, are “irreversible for centuries, if not millennia.”
The report is the most comprehensive assessment of the UN Intergovernmental Panel on Climate Change (IPCC) since 2013 and provides the strongest case to date for man-made global warming, claiming that it is “unequivocal that human influence has warmed the atmosphere, the oceans and the land”.
The report also found that climate change is intensifying, happening at an accelerating rate and is already affecting all regions of the planet.
“It has been clear for decades that the Earth’s climate is changing and the role of human influence on the climate system is undisputed,” Valérie Masson-Delmotte, co-chair of IPCC Working Group I, said in a statement.
Ko Barrett, IPCC vice chair and senior climate advisor at the National Oceanic and Atmospheric Administration, told NBC News the report shows that no matter what humans do in the future, the future will be hotter. than it is now.
“It can be a little demoralizing or depressing to think that there is so much that is kind of irreversible for a long period of time,” Barrett said. “But the good news is that these irreversible changes can be slowed down with quick, sharp and sustained reductions in greenhouse gas emissions.”
The IPCC, established in the late 1980s, is made up of thousands of scientists from 195 member governments who look at the most recent published and peer-reviewed research on global warming and compile the results in a report on global warming. current state of the climate. The assessment, which includes an overview of the future risks and impacts of climate change, generally represents a consensus within the scientific community. Over 230 authors contributed to the latest report.
The assessment comes less than three months before world leaders meet from October 31 to November 12 in Glasgow, Scotland, for the 2021 United Nations Climate Change Conference. Countries are expected to set ambitious reduction targets emissions by 2030, and the IPCC findings are likely to feature prominently in the discussions.
John Kerry, former secretary of state and the president’s special climate envoy, said in a statement that the report should compel leaders to take aggressive action to put the planet on the path to net zero emissions by mid-century.
“What the world needs now is real action. All major economies must engage in aggressive climate action during this critical decade,” he said. “We can achieve the low carbon economy we urgently need, but time is not on our side.”
The report says greenhouse gas emissions from human activities have caused global warming at a rate not seen in at least 2,000 years. Human-induced climate change is estimated to be responsible for about 1.1 degrees Celsius of warming since 1850-1900, the first period with reliable measurements of global surface temperatures, the authors wrote.
What’s more, the report found that global temperatures are expected to exceed 2 degrees Celsius warming this century “unless there are sharp reductions in [carbon dioxide] and other greenhouse gas emissions occur in the decades to come. “
“This report is a reality check,” Masson-Delmotte said in the statement. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are going, what can be done and how we can prepare.”
Climatologists have warned that the increase in average global temperatures should be limited to less than 2 degrees Celsius, or 3.6 degrees Fahrenheit, in order to avoid the most devastating effects of global warming. The 2-degree benchmark was set by climate negotiators in Copenhagen in 2009, but studies have increasingly shown that the target may already be out of reach.
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In a press briefing on Monday, Inger Andersen, United Nations Under-Secretary-General and Executive Director of the United Nations Environment Program, said the IPCC has warned of the dangers of climate change for more than three decades, but that countries – especially the world’s largest economies which are responsible for the bulk of greenhouse gas emissions – have not done enough to solve the problems.
“The world listened, but they didn’t hear,” she said. “The world has listened, but it has not acted with enough force. As a result, climate change is a problem that is here now. No one is safe. And it is getting worse faster.”
The new IPCC assessment goes further than any of the group’s previous reports in linking man-made climate change to the increase in extreme weather events around the world.
“It is practically certain that heat extremes (including heat waves) have become more frequent and intense in most land regions since the 1950s, while cold extremes (including cold waves) have become less frequent and less severe, ”the authors wrote, adding that warming is the“ main driver ”of these changes.
Recent events, including widespread drought in the western United States, heat waves in Europe and North America, and devastating forest fires in Greece, Turkey and the United States, have highlighted the consequences of global warming.
“The climate behaves like an athlete on steroids,” said Erich Fischer, climatologist at ETH Zurich and one of the authors of the IPCC assessment.
The report also details how rising ocean and surface temperatures will cause a myriad of physical climate changes – including drought, heat waves, heavy rains and coastal flooding – in different regions of the planet. .
The assessment is part of the IPCC’s latest summary on climate change, called the Sixth Assessment Report or AR6, which will be released next year. The full report consists of four sections: the report of Working Group I on the Science of Climate Change; the report of Working Group II on vulnerabilities and socio-economic impacts; the report of Working Group III on possible ways to mitigate climate change; and the synthesis report, which reviews the findings of all working groups and incorporates information relevant to decision makers.