The consequences of a warmer planet can be seen and felt from the polar ice caps to sub-Saharan Africa.
In countries such as Kenya as the desert expands, the chances of nomadic farmers finding water for their cattle shrink. Also, in a country where famine threatens up to 10 million lives, crop shortages have devastating effects.
For the UN, these desperate times call for drastic measures. By the middle of this century it wants global CO2 emissions halved compared to their levels in 1990. It also wants the planet to be no more than two degrees centigrade warmer than it was before the Industrial Revolution.
Since the UN adopted its convention on climate change in Rio in 1992, global carbon emissions have risen by 30 percent, a trend the UN wants to reverse.
But developed and emerging economies do not all agree on targets.
The world’s biggest polluter, China, has said it will reduce its “carbon intensity” – or the amount of CO2 emitted per unit of GDP – by between 40 and 45 percent compared to 2005 levels by 2020.
The biggest polluter per capita, the US has pledged to cut emissions by three percent compared to 1990 levels, a target matched by Canada. Compare that to 20 percent for the EU and up to 25 percent for Russia and Japan.
India, like China, says it will reduce its carbon intensity, while Brazil is opting for a 20 percent cut on 2005 levels.
Then there’s the issue of who is going to pay for it.
China, India, South Africa and Brazil have come together to demand that richer countries share their green technology or pay poorer nations to develop their own. Only then they say will they allow international monitoring of their climate action plans.