New Delhi: The UN Climate Panel has released its most comprehensive assessment to date https://www.ipcc.ch/report/ar6/wg1 of climate change.
Here are some of the main findings of the report:
HUMANS ARE TO BLAM – COMPLETE STOP
The Intergovernmental Panel on Climate Change (IPCC) has used its strongest terms to claim that humans are causing climate change.
The austere language marked a departure from previous IPCC reports, which had said it was “extremely likely” that industrial activity was to blame.
“There is no language of uncertainty in this sentence, as there is no uncertainty that global warming is caused by human activity and the burning of fossil fuels,” said Friederike Otto, co-author from the IPCC, climatologist at the University of Oxford.
TEMPERATURES WILL CONTINUE TO INCREASE
The report describes possible futures based on how the world drastically cuts emissions.
But even the most severe cuts are unlikely to prevent global warming 1.5 degrees Celsius above pre-industrial temperatures. Without immediate emission reductions, however, average temperatures could exceed 2 ° C by the end of the century.
Scientists also looked at events considered less likely but still possible, and they couldn’t rule out significant impacts from so-called tipping points, such as the loss of ice in the Arctic or forest dieback.
TIME BECOMES EXTREME
Extreme weather events once considered rare or unprecedented are increasingly common, a trend that will continue even as the world limits global warming to 1.5 ° C.
Strong heat waves that only happened once every 50 years now happen about once a decade. Tropical cyclones are getting stronger. Most land areas see more rain or snow in a year. Severe droughts occur 1.7 times more often. And the fire seasons are getting longer and more intense.
Scientific advancements over the past decade are also helping scientists detect whether climate change has caused or worsened specific weather events.
“In the past, people said ‘you can’t say anything about an individual event’,” said Michael Wehner, IPCC co-author, climatologist at Lawrence Berkeley National Laboratory in California. “But now we can actually make quantitative statements about extreme weather events.”
ARCTIC SUMMERS COULD BE ICE FREE
Summer sea ice atop the Arctic Ocean will disappear entirely at least once by 2050, according to the IPCC’s most optimistic scenario. The region is the fastest warming area of the globe – warming at least twice as fast as the global average.
While sea ice levels in the Arctic vary throughout the year, average summer lows have been declining since the 1970s and are now at their lowest in a thousand years. This melting creates a feedback loop, with the reflective ice giving way to darker water that absorbs solar radiation, causing even more warming.
THE SEA will rise no matter what
The sea level will continue to rise for hundreds or thousands of years. Even if global warming were halted at 1.5 ° C, average sea level would still rise by about 2-3 meters (6-10 feet), and possibly more.
Sea level rise has accelerated, as polar ice caps melt and ocean water warms. Already, associated flooding has nearly doubled in many coastal areas since the 1960s, with one-time coastal waves per century expected to occur once a year by 2100.
Scientists couldn’t rule out extreme elevations of more than 15 meters by 2300, if tipping points trigger uncontrollable warming. “The more we push the climate system… the more likely we are to cross thresholds that we can only project badly,” said IPCC co-author Bob Kopp, climate scientist at Rutgers University.
TO NOT HAVE ENOUGH TIME
Achieving the Paris Agreement’s goal of limiting warming to 1.5 ° C will require sticking to a “carbon budget,” a term describing how much extra carbon can be pumped into the atmosphere before it can be pumped into the atmosphere. this goal is probably out of reach.
The world is now on track to use this budget in about a decade.
With 2.4 trillion tonnes of climate-warming CO2 added to the atmosphere since the mid-1800s, the average global temperature has risen by 1.1 ° C. This leaves an additional 400 billion tonnes that can be added before the carbon budget is skyrocketed. Global emissions currently total just over 40 billion tonnes per year.