Scientists have delivered a “final warning” on the climate crisis, as rising greenhouse gas emissions push the world to the brink of irrevocable damage that only swift and drastic action can avert.
The Intergovernmental Panel on Climate Change (IPCC), made up of the world’s leading climate scientists, set out the final part of its mammoth sixth assessment report on Monday.
The comprehensive review of human knowledge of the climate crisis took hundreds of scientists eight years to compile and runs to thousands of pages, but boiled down to one message: act now, or it will be too late.
The UN secretary general, António Guterres, said: “This report is a clarion call to massively fast-track climate efforts by every country and every sector and on every timeframe. Our world needs climate action on all fronts: everything, everywhere, all at once.”
In sober language, the IPCC set out the devastation that has already been inflicted on swathes of the world. Extreme weather caused by climate breakdown has led to increased deaths from intensifying heatwaves in all regions, millions of lives and homes destroyed in droughts and floods, millions of people facing hunger, and “increasingly irreversible losses” in vital ecosystems.
Monday’s final instalment, called the synthesis report, is almost certain to be the last such assessment while the world still has a chance of limiting global temperature rises to 1.5C above pre-industrial levels, the threshold beyond which our damage to the climate will rapidly become irreversible.
Kaisa Kosonen, a climate expert at Greenpeace International, said: “This report is definitely a final warning on 1.5C. If governments just stay on their current policies, the remaining carbon budget will be used up before the next IPCC report [due in 2030].”
More than 3bn people already live in areas that are “highly vulnerable” to climate breakdown, the IPCC found, and half of the global population now experiences severe water scarcity for at least part of the year. In many areas, the report warned, we are already reaching the limit to which we can adapt to such severe changes, and weather extremes are “increasingly driving displacement” of people in Africa, Asia, North, Central and South America, and the south Pacific.
All of those impacts are set to increase rapidly, as we have failed to reverse the 200-year trend of rising greenhouse gas emissions, despite more than 30 years of warnings from the IPCC, which published its first report in 1990.
The world heats up in response to the accumulation of carbon dioxide and other greenhouse gases in the atmosphere, so every year in which emissions continue to rise eats up the available “carbon budget” and means much more drastic cuts will be needed in future years.
Yet there is still hope of staying within 1.5C, according to the report. Hoesung Lee, the chair of the IPCC, said: “This synthesis report underscores the urgency of taking more ambitious action and shows that, if we act now, we can still secure a livable sustainable future for all.”
Temperatures are now about 1.1C above pre-industrial levels, the IPCC found. If greenhouse gas emissions can be made to peak as soon as possible, and are reduced rapidly in the following years, it may still be possible to avoid the worst ravages that would follow a 1.5C rise.
Ri
