
A UN REPORT published today warns that humans are unequivocally driving global warming, with serious consequences – from heatwaves to rising seas and extreme rain – now being experienced around the world.
The dossier, published by the United Nations’ Intergovernmental Panel on Climate Change, says that the world will reach or exceed temperature rises of 1.5°C – a limit that countries have pledged to keep to in order to avoid the most dangerous consequences of global warming – within the next two decades.
Temperature rises will continue until the middle of the century, the report says, and without fast, deep reductions in greenhouse gases will, over the course of the century, exceed both the 1.5°C target and maximum limit of 2°C set by the 2015 Paris climate treaty.
The report says that rapid and widespread changes to the land, atmosphere and oceans have already occurred — from temperature increases to sea level rises, heatwaves and heavy rainstorms, as well as droughts and cyclones.
It asserts that humans are very likely the main driver in the global retreat of glaciers, declines in Arctic sea ice and rising sea levels. Changes to oceans, sea levels and melting permafrost and glaciers are irreversible for decades, centuries or even millennia.
The study also warns that unlikely events such as ice-sheet collapses, abrupt changes to ocean circulation and much higher warming must not be ruled out.
While the world is already suffering the impacts of climate change, which will worsen with even 1.5°C of warming, the report is clear that further temperature increases will have an even greater impact. Every additional 0.5°C temperature rise will lead to clear increases in the intensity of heatwaves, rainstorms and flooding, and droughts in some regions, it says.
But the report claims that temperature rises have a good chance of remaining below 1.5°C in the long term if carbon emissions are cut to net zero by 2050, followed by efforts to take more carbon dioxide out of the air than is put into the atmosphere, along with cuts to other greenhouse gases.

