UN warns of ‘irreversible’ effects of human-induced climate change

By Vatican News staff reporter

The UN’s Intergovernmental Panel on Climate Change (IPCC) held a press conference on Monday to present its latest and most comprehensive report on the climate crisis.

Entitled “Climate Change 2021: The Physical Science Basis”, the report warned of the dire consequences of global warming and of the responsibility of humans in causing it.

Atmospheric greenhouse gas levels have already reached levels capable of ensuring climate disruption for decades, if not centuries, according to the 200 scientists who compiled the report.

Humans to blame

Topping the 3,000-plus-page report’s conclusions was the affirmation that humans are causing climate change.

“It is unequivocal that human influence has warmed the atmosphere, ocean, and land,” reads the first line of its executive summary.

The scientists say only a fraction of the temperature rise recorded since the 19th century is attributable to natural forces.

The UN Secretary General Antonio Guterres reiterated the point, calling it a “code red” for humanity. “The alarm bells are deafening, and the evidence in irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet and putting billions of people at immediate risk,” he said.

Rising temps

Another key takeaway from the IPCC report was the possible outcomes from cutting carbon emissions to various levels.

Average temperatures are likely to reach 2 degrees Celsius above preindustrial levels by the end of the century unless governments immediately introduce steep emissions cuts.

However, even the severest of curbs are unlikely to keep global warming from exceeding 1.5 degrees.

They also warn about less-likely but possible events called “tipping points” set off by the loss of Artic ice or the dieback of forests.

Worsening weather

Extreme weather is another concern voiced by the report’s authors.

They say weather events once considered rare or unprecedented are now more common, and that this trend will worsen even if global warming is limited to 1.5°C.

Deadly heatwaves are occurring roughly every decade, rather than every 50 years, while hurricanes are stronger and many places are seeing more rain or snowfall each year.

The researchers claimed scientific advances have been made which allow for quantitative statements to be made about extreme weather events.

Melting ice and rising sea levels

Even the report’s most optimistic scenario describes that summertime sea ice atop the Artic Ocean will disappear entirely at least once by the year 2050.

The northern region is currently warming at twice the rate as the global average.

At the same time, sea levels are set to rise for hundreds or thousands of years, no matter what government policies are put in place.

Even if global warming were stopped at 1.5°C, the average sea level could conceivably rise between 2 to 3 meters, if not more.

Lead-up to COP26

The IPCC report comes just three months ahead of the COP26 climate conference in Glasgow, Scotland.

It adds scientific backup to calls for national government to step up their actions for combating climate change.