Crushing climate impacts to hit sooner than feared: UN report
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A dried-up area of the Penuelas Lake in Valparaiso, Chile, last year. A landmark UN draft report says choices societies make now will determine whether our species thrives or simply survives as the 21st century unfolds.
PHOTO: AGENCE FRANCE-PRESSE
PARIS • Climate change will fundamentally reshape life on Earth in the coming decades, even if humans can tame planet-warming greenhouse gas emissions, says a landmark draft report from the UN's climate science advisers.
The choices societies make now will determine whether our species thrives or simply survives as the 21st century unfolds, the Intergovernmental Panel on Climate Change (IPCC) says in its draft report seen exclusively by Agence France-Presse.
By far the most comprehensive catalogue ever assembled of how climate change is upending our world, the report reads like a 4,000-page indictment of humanity's stewardship of the planet.
It warns that previous major climate shocks dramatically altered the environment and wiped out most species, raising the question of whether humanity is sowing the seeds of its own demise.
There are at least four main takeaways in the draft, which has gone through a major revision and is unlikely to change before its release.
The first is that with 1.1 deg C of warming clocked so far, the climate is already changing.
Earlier models predicted we were not likely to see Earth-altering climate change before 2100.
But the report says prolonged warming even beyond 1.5 deg C could produce "progressively serious, centuries' long and, in some cases, irreversible consequences".
Second, the world must face up to this reality and prepare for the onslaught, the draft report says.
In 2050, coastal cities on the "frontline" of the climate crisis will see hundreds of millions of people at risk from floods and increasingly frequent storm surges made more deadly by rising seas.
Thirdly, the report outlines the danger of compound and cascading impacts, along with point-of-no-return thresholds in the climate system known as tipping points, which scientists have barely begun to measure and understand.
Recent research has shown that warming of 2 deg C could push the melting of ice sheets atop Greenland and the West Antarctic - with enough frozen water to lift oceans 13 m - past a point of no return.
There is no easy solution to such a tangle of problems, said the World Bank's former chief economist Nicholas Stern, author of the landmark Stern Review on the Economics of Climate Change.
There is very little good news in the report, but the IPCC stresses that much can be done to avoid worst-case scenarios and prepare for impacts that can no longer be averted, the final takeaway.
Conservation and restoration of so-called blue carbon ecosystems - kelp and mangrove forests, for example - will enhance carbon stocks and protect against storm surges, as well as providing wildlife habitats, coastal livelihoods and food security.
Transitioning to more plant-based diets could also reduce food-related emissions as much as 70 per cent by 2050.
AGENCE FRANCE-PRESSE
