New York: Humanity’s damaging impact on the climate is a “statement of fact”, say UN scientists in a landmark study. The report says that ongoing emissions of warming gases could also see a key temperature limit broken in just over a decade.
The authors also show that a rise in sea levels approaching 2m by the end of this century “cannot be ruled out”.
But there is new hope that deep cuts in emissions of greenhouse gases could stabilise rising temperatures.
This sober assessment from the Intergovernmental Panel on Climate Change (IPCC) features in a 42-page document known as the Summary for Policymakers.
It leads a series of reports that will be published over the coming months and is the first major review of the science of climate change since 2013. Its release comes less than three months before a key climate summit in Glasgow known as COP26.
“Today’s IPCC Working Group 1 Report is a code red for humanity,” said UN Secretary-General, António Guterres.
“If we combine forces now, we can avert climate catastrophe. But, as today’s report makes clear, there is no time for delay and no room for excuses. I count on government leaders and all stakeholders to ensure COP26 is a success.”
In strong, confident tones, the IPCC’s document says “it is unequivocal that human influence has warmed the atmosphere, oceans, and land”.
The authors say that since 1970, global surface temperatures have risen faster than in any other 50-year period over the past 2,000 years.
This warming is “already affecting many weather and climate extremes in every region across the globe”.
Whether it’s heatwaves like the ones recently experienced in Greece and western North America, or floods like those in Germany and China, “their attribution to human influence has strengthened” over the past decade.
The new report also makes clear that the warming we’ve experienced to date has made changes to many of our planetary support systems that are irreversible on timescales of centuries to millennia.
The oceans will continue to warm and become more acidic. Mountain and polar glaciers will continue melting for decades or centuries.
When it comes to sea-level rise, scientists have modelled a likely range for different levels of emissions.
However, a rise of around 2m by the end of this century cannot be ruled out – and neither can a 5m rise by 2150.
Such outcomes, while unlikely, would threaten many millions of more people in coastal areas with flooding by 2100.
One key aspect of the report is the expected rate of temperature rise and what it means for the safety of humanity.
This new report says that under all the emissions scenarios considered by the scientists, both targets will be broken this century unless huge cuts in carbon take place.
The authors believe that 1.5C will be reached by 2040 in all scenarios. If emissions aren’t slashed in the next few years, this will happen even earlier.
This was predicted in the IPCC’s special report on 1.5C in 2018 and this new study now confirms it, BBC News reported.
