Cutting global greenhouse emissions by half of 1990 levels by 2050 will not be sufficient to prevent major damage from climate change, say scientists in a Commentary published today on Nature Reports Climate Change.
Earlier this week, environment ministers from the world’s leading industrialised countries, the Group of Eight, called for a deal to slash global greenhouse gas emissions by 50% by mid-century.
This would still commit the world to substantial harm, even if it is “widely considered to be the most stringent politically achievable target”, says Martin Parry, who co-chaired the impacts assessment group for the Intergovernmental Panel of Climate Change, and others.
By analysing the regional and global impacts that would occur by 2050 and 2100 for various greenhouse gas emissions targets, Parry and co-authors argue that compared with 50 per cent cuts, slashing emissions by 80% below 1990 levels by mid-century would substantially reduce the damage caused; for example, halving the number at risk of water stress and flooding.
They call on world leaders at the forthcoming UN climate change talks in Bonn in June and July’s G8 summit in Hokkadio, Japan to boldly declare their commitment to dramatically reducing greenhouse gases.
The current global food crisis should serve as a ‘wake-up call’ to G8 and UN leaders, they say, who suffer from “false optimism’ that “we can find a way to fully avoid all the serious threats of climate change”.
They caution, however, than even with 80% cuts, damages will still be large, which is why world leaders must also step up their commitment on funding adaptation. Current efforts are vastly below par, with a mere US$67 million donated to date of the estimated tens of billions needed for developing-world adaptation alone.
At the same time as world leaders are being urged to consider stricter targets for 2050, others are urging them to seriously consider shorter term targets – for 2020 – a goal believed to be important if emissions are to peak within the next 10 to 20 years.