Immediate action is required if we are to avoid unmanageable changes and intolerable impacts from climate change, says this editorial in Science.
Carbon dioxide emissions must level off by 2015–20 and then decrease to no more than a third of that level by 2100, and global average temperature must not rise by more than 2–2.5 degrees centigrade above pre-industrial levels.
These targets cannot be met without immediate action, say Rosina M. Bierbaum and Peter H. Raven ― co-chairs of the climate change report presented to the UN earlier this year (27 February).
They argue that action should combine mitigation strategies to reduce the pace and magnitude of changes with strategies for adapting to inevitable changes.
Mitigation must focus on improving the efficiency of the transport sector and increasing the use of both biofuels and environmentally friendly coal-fired power plants.
Adapting to climate change means making cities climate-resilient and energy-efficient. Institutions must also be strengthened against weather-related disasters.
Building on land less than three feet above sea level should also be avoided and countries must be prepared for increasing numbers of climate-change refugees, say the authors.
The world's poor will bear the heaviest burden of climate change. Unless the global community acts now, their fate will not be improved.