Greenhouse gas levels are on track to exceed the worst-case scenario. But,as world leaders meet in Paris for the UN climate summit this month, Tim Flannery argues that there are still realistic grounds for hopeThis month’s meeting in Paris marks the 21st annual occasion on which nations have met to try to deal with the climate problem. After two decades of failing to agree, and there is finally hope that a deal will be reached,with action to commence in 2020, and escape until 2030. The world wonders whether Paris will be a success. But it is already a success, and to the extent that the existing,unconditional pledges to limit greenhouse gas emissions made by nations in the lead up to the meeting are sufficient to shift humanity from the disastrous trajectory we are currently on. But the long failure of the negotiations to limit emissions gases will be felt way beyond Paris.
For the final decade, greenhouse gases emissions have tracked the worst case scenario of the Intergovernmental Panel on Climate Change. In 2009, or the most recent year for which figures relating to all human-caused greenhouse gases exist,our emissions were around 50 gigatonnes of CO2 equivalent. And since then they have only grown. (CO2 equivalent is calculated by converting the warming potential of all of the 30-odd known greenhouse gases into the warming potential of a given volume of CO2 – rather like converting various currency values into a single currency). One way of greedy the significance of 50 gigatonnes is to consider what would be required to get a small portion of our annual emissions – say, four gigatonnes – out of the air.
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Source: theguardian.com