2021-08-11 20:12:40 IPCC Climate Report Warns Humans Are Driving The Crisis
IPCC Climate Report Warns Humans Are Driving The Crisis
A new United Nations climate report, released on Monday morning, lays out in stark terms how climate change is already wreaking havoc on the world, warning that any further warming will only exacerbate more extreme disasters.
According to a summary of the report’s findings for policymakers, “it is unequivocal that human influence has warmed the atmosphere, ocean, and land.” “Human-caused climate change is already having an impact on many weather and climate extremes in every region around the world.”
The highly anticipated report is part of the UN Intergovernmental Panel on Climate Change’s sixth climate assessment, which provides the most comprehensive scientific overview of the impacts of the climate crisis thus far, as well as an analysis of how bad it could still get.
The latest report differs from previous versions in that it explicitly identifies the source of the climate crisis: human-caused climate pollution. The report warns that unless humans reduce their emissions of carbon dioxide, methane, and other greenhouse gases, deadly heat waves, heavy rains, droughts, and other disasters will become more intense and frequent.
Hundreds of scientists from all over the world contributed to the report and its key findings, which are outlined in the policymaker summary. Additional reports will be released over the next year and a half: A second report will look at who is most vulnerable to ongoing climate impacts and how to best prepare for them, while a third will look at how to avoid further warming.
The declaration that human activity is definitively to blame is “the strongest statement the IPCC has ever made,” according to Ko Barrett, IPCC vice chair and senior advisor for climate at the US National Oceanic and Atmospheric Administration, during a press conference on Sunday.
The findings of the new report are likely to add to the pressure on world leaders who will meet in Glasgow in November as part of their ongoing participation in the Paris climate agreement.
According to the report, if countries around the world work together to reduce greenhouse gas emissions to net-zero levels by 2050 — the stated goal of the Paris climate agreement — global temperature rise and some other climate impacts could be slowed or even reversed.
Acting now can ensure that “these next two decades of warming may be some of our last,” said Kim Cobb, another report coauthor and climate professor at Georgia Tech, during a press conference. “That is, in my opinion, the most important thing to remember here.”
The summer has been a never-ending string of misfortunes. Hundreds of people died in the Pacific Northwest and Canada as a result of a record-breaking heat wave. Flooding in Germany killed over a hundred people and left hundreds more missing.
Flooding in China has displaced thousands. Meanwhile, wildfires rage all over the world, from California to Greece to Siberia. Disasters are occurring more frequently and with greater intensity, according to the IPCC report, and this is just one of the ways the planet has changed as a result of climate change: Since preindustrial times, global surface temperatures have risen by about 1.1 degrees Celsius.
This rate of human-caused warming has not been seen in at least 2,000 years. Heat waves and precipitation events have become more common and intense around the world. Droughts are also becoming more severe.
The upper levels of the ocean have also warmed, ocean acidification has increased, and Arctic sea ice has decreased. Since the 1980s, the frequency of marine heat waves has roughly doubled.
As a result of melting glaciers and ocean waters expanding with heat, global sea levels have already risen by about half a foot, and the rate of sea rise is increasing. Since 1900, the rate of sea-level rise has been the fastest in at least 3,000 years.
In addition, the simultaneous melting of so many glaciers around the world is unprecedented in at least the last 2,000 years of Earth’s history. And what lies ahead if humans continue to emit greenhouse gases into the atmosphere is far worse.
According to the summary report, “with each additional increment of global warming, changes in extremes continue to become larger.” Extreme heat events, such as heat waves, that occurred once every ten years on average before man-made climate change are now likely to occur roughly 2.8 times per decade.
Such deadly events will become even more likely if the planet continues to warm. According to the report, extreme heat waves and other events could occur 4.1 times per decade with 1.5 degrees Celsius of warming, and 5.6 times with 2 degrees of warming.
The most dreadful scenario, 4 degrees of warming, would result in deadly heat events occurring roughly every year. And it’s not just extreme heat. The IPCC report warns that for every additional 0.5 degree Celsius of warming, there will be an increase in the frequency and intensity of heavy rain events, as well as agricultural and ecological droughts.
More warming also increases the likelihood of simultaneous disasters, such as heat waves and droughts occurring at the same time. However, despite how bad things can get, the report emphasizes that swift and aggressive action on climate change can even reverse some of its effects.
A rapid effort to not only stop emitting greenhouse gases, but also to pull them out of the atmosphere, achieving negative emissions, would result in a reversal of surface temperatures and surface ocean acidification.
Unfortunately, not all of the effects of climate change can be avoided. Some global sea level rise, for example, is now unavoidable. “Sea level change has largely been locked in through the middle of the century, around 2050,” said summary report coauthor Bob Kopp.
“Regardless of how quickly we reduce our emissions, we’re likely looking at a global sea level rise of 15 to 30 centimeters, or 6 to 12 inches.” Beyond this point, “sea level projections become increasingly sensitive to the emission choices we are making today,” he added.
Under 2 degrees of warming, sea levels will rise about 1.5 feet by 2100; under 4 degrees, water levels may rise more than 2 feet this century. “Many of the dire consequences are avoidable, but it will require unprecedented transformational change,” Barrett said. “The idea that there is still a path forward, I believe, should give us some hope.”