ECO welcomes the fact Parties are finally starting to examine the implications of future emission pathways that will allow them to meet the ultimate objective of the Convention as defined in Article 2. This came up in the Ad-Hoc Working Group (AWG) workshop on Tuesday, and seems to have penetrated the discussions here in Nairobi more generally.
An examination of the limits on global emissions over the long term necessary to keep global warming to below 2oC is an essential parameter for negotiating emission reductions requirements for Annex 1 countries, as well as for understanding the scale of the efforts needed in developing countries.
It is possible to estimate the atmospheric greenhouse gas (GHG) concentration levels, and from there annual emission levels, that will have a good chance of keeping global warming to less than 2oC above pre-industrial levels. Timing is also key. There are remaining uncertainties in precisely quantifying the climate sensitivity, so the best the world can do at this stage is to define a range of probabilities for meeting the long term target. This is a very good reason to keep the system of five-year commitment periods in the future iterations of the Protocol, but that is another story.
The figure below shows one scenario for the division of the annual emissions ‘pie’ between different groups of countries within an overall cap that will put the world on a pathway towards stabilisation at a given concentration level. The stabilisation level will determine the likelihood of keeping warming to below the desired target. Using the Intergovernmental Panel on Climate Change language, a 550 ppm concentration level is ‘likely’ (65-90 per cent chance) to overshoot 2oC, and a 450 ppm concentration level has a ‘medium likelihood’ (35-65 per cent chance) to overshoot 2oC. To make it ‘likely’ to stay below the 2oC target, concentration targets then must be for 400 ppm or lower.
Meeting the ultimate objective of the climate convention – to avoid dangerous climate change – is going to require significant action on a global basis. The politics of that will of course be complicated, but the science is certainly clear.
The world has to act even faster and take more dramatic action if it is to avoid damage associated with a 2ºC global average temperature rise. This means that for now, the aim has to be stabilising GHGs in the atmosphere and then seeking to bring them down as rapidly as possible if there is to be a reasonable chance of keeping global temperature rise below 2ºC.
To meet these goals dramatic reductions in GHG emissions are needed, and they are needed soon. From a moral, legal and practical perspective, the initial burden of emissions reductions has to fall on industrialised countries. Domestic reductions of at least 30 per cent on 1990 levels (the ‘baseline’ year for the Kyoto Protocol) by 2020 from industrialised countries are required, with a target of at least 75 per cent reductions by mid-century.
Globally, there is a need to ensure emissions peak as soon as possible, and no later than 2015-2020, and then reduce them by 50 per cent by mid-century. This means not only that industrialised countries must make dramatic reductions in the next decade but a fair means must be found for engaging rapidly industrialising countries in reduction efforts in the near future.
Consequences of delay in the process of reducing emissions means the world will face a dire global emergency in the 2020s which will require rates of emission reductions in the past only associated with massive economic collapse such as the collapse of the Soviet Union. The world must not be forced to choose between economic catastrophe and climate catastrophe. The most likely outcome in that case would be both, and we have a good chance of avoiding this if we Act Now.