‘Nowhere to Run’: UN report says global warming is approaching limits
The Earth is getting so hot that temperatures in a decade or so will likely exceed a level of warming that world leaders have sought to prevent, according to a report released on Monday that the United Nations called a “code red for humanity.”
“It’s just guaranteed to get worse,” said Linda Mearns, co-author of the report, senior climatologist at the US National Center for Atmospheric Research. “Nowhere to run, nowhere to hide. “
But scientists have also quieted a little about the likelihood of absolute worst climate disasters.
The authoritative report of the Intergovernmental Panel on Climate Change (IPCC), which calls climate change clearly man-made and “unequivocal,” makes more accurate and warmer predictions for the 21st century than the last time it was released in 2013.
Each of the five scenarios for the future, based on reducing carbon emissions, exceeds the more stringent of the two thresholds set in the 2015 Paris climate agreement. World leaders then agreed to try to limit the warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above late 19th century levels, as problems quickly escalate thereafter. The world has already warmed by almost 1.1 degrees Celsius (2 degrees Fahrenheit) since then.
In each scenario, according to the report, the world will cross the 1.5 degree Celsius warming mark in the 2030s, earlier than some past predictions. Warming has accelerated in recent years, data shows.
“Our report shows that we must prepare to enter this level of warming in the coming decades. But we can avoid new levels of warming by acting on greenhouse gas emissions, ”said report co-chair Valérie Masson-Delmotte, climatologist at the French Laboratory for Climate and Environmental Sciences at the University. Paris-Saclay.
In three scenarios, the world will likely also exceed 2 degrees Celsius (3.6 degrees Fahrenheit) compared to pre-industrial times – Paris’ less strict target – with heat waves, droughts and torrential rains much worse. , unless there are big reductions in emissions, the report said.
“This report tells us that recent climate change is widespread, rapid and intensifying, unprecedented in thousands of years,” said IPCC Vice Chairman Ko Barrett, Senior Climate Advisor for the National Oceanic and Atmospheric Administration of the United States.
With crucial international climate talks coming to Scotland in November, world leaders said the report requires them to step up efforts to reduce carbon pollution. US Secretary of State Anthony Blinken called it a “brutal recall”.
The more than 3,000-page report by 234 scientists said warming is already accelerating sea level rise and worsening extremes such as heat waves, droughts, floods and storms. Tropical cyclones get stronger and wetter, as arctic sea ice decreases in summer and permafrost melts. All of these trends will get worse, according to the report.
For example, the type of heat wave that only happened once every 50 years now happens once a decade, and if the world warms another degree Celsius (1.8 degrees Fahrenheit), that will occur twice every seven years, according to the report.
As the planet warms, places will be affected more not only by extreme weather conditions, but also by multiple climate disasters at once, according to the report. It’s like what’s happening in the western United States now, where heat waves, drought and wildfires are adding to the damage, Mearns said. The extreme heat is also causing massive fires in Greece and Turkey.
Some of the damage caused by climate change – shrinking ice caps, rising sea levels, and changes in the oceans as they lose oxygen and become more acidic – are “irreversible for centuries or even more. millennia, ”according to the report.
The world is “locked in” to 15 to 30 centimeters (6 to 12 inches) of sea level rise by the middle of the century, said report co-author Bob Kopp from Rutgers University.
Scientists have been sending this message for more than three decades, but the world has not listened, said the executive director of the United Nations Environment Program, Inger Andersen.
For the first time, the report offers an interactive atlas allowing people to see what happened and what could happen where they live.
Almost all of the warming that has occurred on Earth can be attributed to emissions of heat-trapping gases such as carbon dioxide and methane. At most, natural forces or sheer chance can explain one or two tenths of a degree of warming, depending on the report.
The report describes five different future scenarios based on reducing global carbon emissions. They are: a future with incredibly large and rapid pollution reductions; another with intense but not so massive pollution reductions; a scenario with moderate emission reductions; a fourth scenario in which current plans to reduce pollution slightly continue; and a fifth possible future involving a continuing increase in carbon pollution.
In five previous reports, the world was on this latest hottest track, often dubbed “business as usual”. But this time the world is somewhere between the moderate path and the low pollution reduction scenario due to progress in curbing climate change, said report co-author Claudia Tebaldi, a scientist at the US Pacific Northwest. National Lab.
While calling the report a “code red for humanity,” UN Secretary-General Antonio Guterres kept a silver lining that world leaders could still somehow prevent a 1.5 degree warming. , which he said is “dangerously close”.
Alok Sharma, chairman of the upcoming climate talks in Scotland, urged leaders to do more so that they can “credibly say that we have kept 1.5 degrees alive”.
“Anything we can do to limit, slow down, will pay off,” Tebaldi said. “And if we can’t get to 1.5, it’s probably going to be painful, but you better not give up. “
In the report’s worst-case scenario, the world could be about 3.3 degrees Celsius (5.9 degrees Fahrenheit) warmer than it is today by the turn of the century. But that scenario looks increasingly unlikely, said report co-author and climatologist Zeke Hausfather, director of climate change at the Breakthrough Institute.
“We’re a lot less likely to be lucky and end up with less warming than we thought,” Hausfather said. “At the same time, the chances of ending up somewhere much worse than we expected if we cut our emissions are significantly lower.”
The report says ultra-catastrophic disasters – commonly referred to as “tipping points,” such as the collapse of the ice cap and abrupt slowing of ocean currents – are “unlikely” but cannot be ruled out. The much-talked-about shutdown of Atlantic Ocean currents, which would trigger massive climate change, is something that’s unlikely to happen in this century, Kopp said.
A “major breakthrough” in understanding the rate at which the world is heating up with every ton of carbon dioxide emitted has allowed scientists to be much more precise in the scenarios in this report, Mason-Delmotte said.
In a new move, scientists have pointed out how reducing levels of methane in the air – a powerful but short-lived gas that has reached record levels – could help curb warming in the short term. A lot of methane in the atmosphere comes from leaks of natural gas, a major energy source. Cattle also produce large amounts of gas, much of it in cattle burps.
Over 100 countries have informally committed to achieving ‘net zero’ man-made carbon dioxide emissions by mid-century, which will be a key part of the negotiations in Scotland. The report said these commitments are essential.
“It is still possible to prevent many of the more serious impacts,” Barrett said.