Humans are indisputably responsible for climate change, a new report has determined. The UN’s Intergovernmental Panel on Climate Change says human activity is causing extreme weather events such as heatwaves, heavy rainfall and drought.
It’s warning that global temperatures will increase by 1.5 degrees over the next 20 years. More than 200 scientists reviewed over 14,000 studies for the report, which is the culmination of a marathon five-year assessment.
“Unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to 1.5°C will be beyond reach,” scientist Valérie Masson-Delmotte told reporters as the Intergovernmental Panel on Climate Change (IPCC) released its report on Monday.
Under the 2015 Paris climate agreement, world leaders committed to trying to limit warming to 1.5 degrees Celsius since the late 19th century because problems mount quickly after that.
“The world listened but it did not hear. The world listened but it did not act strongly enough,” deplored United Nations Environment Program Executive Director Inger Andersen, noting that scientists had issued this message for three decades.
“Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea-level rise—are irreversible over hundreds to thousands of years,” the IPCC said.
Shrinking ice and heatwaves, droughts, floods and storms are already visible impacts of climate change. All of these trends will get worse, the report predicted.
For example, the kind of heatwave that used to happen only once every 50 years now happens once a decade. If the world warms another degree Celsius, it will happen twice every seven years, the report said.
“It’s just guaranteed that it’s going to get worse,” said report co-author Linda Mearns, a senior climate scientist at the US National Centre for Atmospheric Research. “I don’t see any area that is safe … Nowhere to run, nowhere to hide.”
IPCC scientists say “the role of human influence on the climate system is undisputed.”
In three scenarios, the world will also likely exceed 2 degrees Celsius over pre-industrial times with far worse heat waves, droughts and flood-inducing downpours.
“The only way to limit global warming is net-zero CO2 emissions,” Masson-Delmotte said. “It’s all in our hands.”
European Commission Vice President Frans Timmermans tweeted that the report “shows the immense urgency of acting now to tackle the climate crisis. It’s not too late to stem the tide and prevent runaway climate change, but only if we act decisively now and all act together.”
Several major heatwaves over the summer led to large wildfires, including ones that continue to spread in southern Europe.
“The report confirms in an impressive way the connection between man-made climate change and weather extremes. Floods after heavy rains, as we have just experienced, are increasing, as are heat waves and forest fires, which have plagued us in recent years,” said German Environment Minister Svenja Schulze, whose country was last month hit by deadly flooding.