© Reuters. FILE PHOTO: A man looks outside a house in an area affected by flooding caused by heavy rains in Bad Muenstereifel, Germany, on July 19, 2021. REUTERS / Wolfgang Rattay /
By Nina Chestney and Andrea Januta
(Reuters) – The UN climate panel issued a dire warning on Monday, saying the world is dangerously close to runaway warming, and that humans are “unequivocally” to blame.
Greenhouse gas levels in the atmosphere are already high enough to guarantee climate change for decades, if not centuries, scientists warn in a report by the Intergovernmental Panel on Climate Change (IPCC). https://www.ipcc.ch/report/ar6/wg1
That is in addition to the deadly heat waves, powerful hurricanes and other extreme weather events that are occurring now and are likely to become more severe.
Describing the report as a “code red for humanity,” UN Secretary-General António Guterres called for an immediate end to energy from coal and other highly polluting fossil fuels.
“The alarm bells are deafening,” Guterres said in a statement. “This report must sound like a death sentence for coal and fossil fuels, before they destroy our planet.”
The IPCC report comes just three months before a major UN climate conference in Glasgow, Scotland, where nations will be under pressure to promise ambitious climate action and substantial funding.
Drawing on more than 14,000 scientific studies, the report offers the most comprehensive and detailed picture yet of how climate change is altering the natural world and what could still lie ahead.
Unless immediate, rapid, and large-scale action is taken to reduce emissions, the report says, the average global temperature will likely cross the 1.5 degree Celsius warming threshold in the next 20 years.
Until now, the promises of nations to reduce emissions https://reut.rs/3ywxDyE have been inadequate to reduce the level of accumulated greenhouse gases in the atmosphere.
In reaction to the findings, governments and activists expressed alarm.
“The IPCC report underscores the overwhelming urgency of this moment,” US climate envoy John Kerry said in a statement. “The world must come together before the ability to limit global warming to 1.5 degrees Celsius is out of reach.”
Emissions “unequivocally caused by human activities” have raised the current average global temperature 1.1 ° C higher than the pre-industrial average, and would have pushed it 0.5 ° C higher if not for the moderating effect of pollution in the atmosphere, says the report.
That means that as societies move away from fossil fuels, much of the aerosols in the air will disappear and temperatures could rise.
Scientists warn that warming more than 1.5 ° C above the pre-industrial average could trigger runaway climate change with catastrophic impacts, such as heat so intense that crops fail or people die simply from being outdoors.
Each additional 0.5 ° C of warming will also increase the intensity and frequency of heat extremes and heavy rains, as well as droughts in some regions. Because temperatures fluctuate from year to year, scientists measure climate warming in terms of 20-year averages.
“We have all the evidence we need to show that we are in a climate crisis,” said three-time IPCC co-author Sonia Seneviratne, a climate scientist at ETH Zurich, who doubts she will sign up for a fourth report. “Policy makers have enough information. You may ask yourself: Is it a significant use of scientists’ time, if nothing is being done?”
The 1.1 ° C warming already recorded has been enough to trigger disastrous weather. This year, heat waves killed hundreds in the Pacific Northwest and broke records around the world. Wildfires fueled by heat and drought are devastating entire towns in the western US, releasing record emissions from Siberian forests and leading Greeks to flee their lands by ferry. (Graph on global warming) https://tmsnrt.rs/3wcycMk
“Every part of warming matters,” said IPCC co-author Ed. Hawkins (NASDAQ :), climate scientist at the University of Reading in Great Britain. “The consequences get worse and worse as we heat up.”
It is “practically certain” that the Greenland ice sheet will continue to melt. Oceans will continue to warm and surface levels will rise for centuries to come. (Graphic about Greenland) https://tmsnrt.rs/2Qvivkg
It is too late to prevent these particular changes. The best the world can do is slow them down so countries have more time to prepare and adapt.
“We are now engaged with some aspects of climate change, some of which are irreversible for hundreds or thousands of years,” said IPCC co-author Tamsin Edwards, a climate scientist at King’s College London. “But the more we limit warming, the more we can avoid or slow down those changes.”
‘WE STILL HAVE TO MAKE DECISIONS’
But even to curb climate change, the report says, the world is running out of time.
If the world dramatically cuts emissions over the next decade, average temperatures could still rise 1.5 ° C by 2040 and possibly 1.6 ° C by 2060 before stabilizing.
If the world does not drastically reduce emissions and instead continue on the current trajectory, the planet could see a warming of 2.0 ° C by 2060 and 2.7 ° C by the end of the century.
The earth has not been this warm since the Pliocene epoch about 3 million years ago, when the first ancestors of humans appeared and the oceans were 25 meters (82 feet) higher than they are today.
It could get even worse, if warming triggers feedback loops that release even more carbon emissions that cause climate warming, such as the melting of Arctic permafrost or the dieback of global forests. Under these high-emission scenarios, the Earth could roast at temperatures 4.4 ° C above the pre-industrial average for 2081-2100.
“We have already changed our planet, and we will have to live with some of those changes for centuries and millennia to come,” said IPCC co-author Joeri Rogelj, a climate scientist at Imperial College London.
The question now, he said, is how many more irreversible changes we avoid: “We still have options to make.”