Each of five scenarios for the future, based on how much carbon emissions are cut, passes the more stringent of two thresholds set in the 2015 Paris climate agreement.
Earth's climate is getting so hot that temperatures in about a decade will probably blow past a level of warming that world leaders have sought to prevent, according to a report released Monday that the United Nations calls a 바카라code red for humanity.바카라
바카라It's just guaranteed that it's going to get worse,바카라 said report co-author Linda Mearns, a senior climate scientist at the US National Center for Atmospheric Research.
바카라I don't see any area that is safe ... Nowhere to run, nowhere to hide.바카라
But scientists also eased back a bit on the likelihood of the absolute worst climate catastrophes.
The authoritative Intergovernmental Panel on Climate Change (IPCC) report, which calls climate change clearly human-caused and 바카라unequivocal,바카라 makes more precise and warmer forecasts for the 21st century than it did last time it was issued in 2013.
Each of five scenarios for the future, based on how much carbon emissions are cut, passes the more stringent of two thresholds set in the 2015 Paris climate agreement. World leaders agreed then to try to limit warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since the late 19th century because problems mount quickly after that.
The limit is only a few tenths of a degree hotter than now because the world has already warmed nearly 1.1 degrees Celsius (2 degrees Fahrenheit) in the past century and a half.
Under each scenario, the report said, the world will cross the 1.5 degrees Celsius warming mark in the 2030s, earlier than some past predictions. Warming has ramped up in recent years, data shows.
In three scenarios, the world will also likely exceed 2 degrees Celsius (3.6 degrees Fahrenheit) over pre-industrial times 바카라 the other, less stringent Paris goal 바카라 with far worse heat waves, droughts and flood-inducing downpours 바카라unless deep reductions in carbon dioxide and other greenhouse gas emissions occur in the coming decades,바카라 the report said.
바카라This report tells us that recent changes in the climate are widespread, rapid and intensifying, unprecedented in thousands of years,바카라 said IPCC Vice Chair Ko Barrett, senior climate adviser for the U.S. National Oceanic and Atmospheric Administration. 바카라The changes we experience will increase with further warming.바카라
The 3,000-plus-page report from 234 scientists said warming is already accelerating sea level rise, shrinking ice and worsening extremes such as heat waves, droughts, floods and storms. Tropical cyclones are getting stronger and wetter, while Arctic sea ice is dwindling in the summer and permafrost is thawing. All of these trends will get worse, the report said.
For example, the kind of heat wave that used to happen only once every 50 years now happens once a decade, and if the world warms another degree Celsius (1.8 degrees Fahrenheit), it will happen twice every seven years, the report said.
As the planet warms, places will get hit more not just by extreme weather but by multiple climate disasters that occur simultaneously, the report said. That's like what's now happening in the Western U.S., where heat waves, drought and wildfires compound the damage, Mearns said.
Some harm from climate change 바카라 dwindling ice sheets, rising sea levels and changes in the oceans as they lose oxygen and become more acidic 바카라 are 바카라irreversible for centuries to millennia,바카라 the report said.
The world is 바카라locked in바카라 to 15 to 30 centimeters (6 to 12 inches) of sea level rise by mid-century, said report co-author Bob Kopp of Rutgers University.
Nearly all of the warming that has happened on Earth can be blamed on emissions of heat-trapping gases such as carbon dioxide and methane. At most, natural forces like the sun or simple randomness can explain one- or two-tenths of a degree of warming, the report said.
The report described five different future scenarios based on how much the world reduces carbon emissions. They are: a future with incredibly large and quick pollution cuts; another with intense pollution cuts but not quite as massive; a scenario with moderate emissions; a fourth scenario where current plans to make small pollution reductions continue; and a fifth possible future involving continued increases in carbon pollution.
In five previous reports, the world was on that final hottest path, often nicknamed 바카라business as usual.바카라 But this time, the world is somewhere between the moderate emissions path and the small pollution reductions scenario because of progress to curb climate change, said report co-author Claudia Tebaldi, a scientist at the U.S. Pacific Northwest National Lab.
In a way, the world can stay at the 1.5-degree threshold with extreme and quick emission cuts, but even then, warming would hit 1.5 degrees in a decade, rise a tad and then come back down, said co-author Maisia Rojas Corrada, director of the Center for Climate and Resilience Research in Chile.
While calling the report 바카라a code red for humanity,바카라 United Nations Secretary-General Antonio Guterres kept a sliver of hope that world leaders could still somehow prevent 1.5 degrees of warming, which he said is 바카라perilously close.바카라
바카라Anything we can do to limit, to slow down, is going to pay off,바카라 Tebaldi said. 바카라And if we cannot get to 1.5, it's probably going to be painful, but it's better not to give up.바카라
In the report's worst-case scenario, the world could be around 3.3 degrees Celsius (5.9 degrees Fahrenheit) hotter than now by the end of the century. But that scenario looks increasingly unlikely, said report co-author and climate scientist Zeke Hausfather, climate change director of the Breakthrough Institute. Both extremes are looking less likely, he said.
바카라We are a lot less likely to get lucky and end up with less warming than we thought. We won't be able to meet Paris Agreement goals without rapid near-term reductions in our emissions,바카라 Hausfather said.
바카라At the same time, the odds of ending up in a much worse place than we expected if we do reduce our emissions are notably lower.바카라
The report said ultra-catastrophic disasters, commonly called 바카라tipping points,바카라 like ice sheet collapses and the abrupt slowdown of ocean currents are 바카라low likelihood바카라 but cannot be ruled out. The much talked-about shutdown of Atlantic ocean currents, which would trigger massive weather shifts, is something that's unlikely to happen in this century, Kopp said.