The new IPCC report provides a clear scientific limit on the volume of CO2 we can emit to avoid 2°C. Sandbag argues that the 2015 agreement must not only incorporate this carbon budget, but begin the tougher job of dividing it fairly between countries.

Yesterday saw the Intergovernmental Panel on Climate Change publish its full report evaluating the physical science behind climate change. This report provides the clearest link yet between anthropogenic greenhouse gas emissions and global warming, and gives clear injunctions to rapidly and radically reduce these emissions if we are to avoid dangerous climate change. Not only does it find that it’s “extremely likely” (95-100% probability) that human activities are causing global warming, it finds that we must keep our remaining CO2 emissions below 990 billion tonnes total to have a “likely” chance (66-100% probability) of avoiding 2°C of global warming. This budget provides a clear framework for governments negotiating an international climate deal in 2015 if they are serious about fulfilling their pledges to avoid 2° under the Copenhagen Accord. This call to formally acknowledge the IPCC global carbon budget in the international negotiations has already been picked up by economist, Lord Stern and by EU Climate Commissioner, Connie Hedegaard.

But while setting a global carbon budget is an essential first step, it still leaves the fundamental political question unanswered: how should that carbon budget be divided between nations? So far, national targets, where they exist, have been set in a politically haphazard way, with little regard to how these all stack up under a collective two degree carbon budget. Now with that budget clearly in view, we are obliged, in the words of Bill McKibben to “Do the math”.

The simplest and, in our view, the fairest way of carving up that carbon budget is to divide it evenly between countries based on population. Carbon pollution space is a new scarce global resource that does not respect the conventional national boundaries by which natural resources are usually divided and therefore better lends itself to a per capita distribution. Because territorial accounting of “smokestack” emissions has been recorded since 1990 under the UNFCCC, we argue that it is best to adhere to this system if we are to take account of the relative efforts of different nations to curb their emissions since the dangers of climate change were made widely known (i.e. by the first IPCC report). This is particularly important when we consider that 37% of the carbon budget available from 1990 has already been used up, with OECD countries using a very disproportionate share of that (i.e. 50% while only accounting of 20% of 1990 population). These historical emissions cannot be easily captured by upstream approaches that focus on fossil-fuel producers or downstream approaches that focus on end-consumers of carbon-intensive goods and services.

This “budgets approach” was first clearly formulated by the esteemed German Advisory Council on Global Change (WBGU) ahead of the Copenhagen climate conference in 2009; but despite being widely circulated and positively received, this approach has been systematically under-represented in effort-sharing discussions since. Instead the discussions have been monopolised by approaches which implicitly award the largest historical emitters a disproportionate share of the future emissions space. In an effort to reverse that trend and revive the budgets approach, Sandbag prepared a special report The Sovereign Emissions Rights Framework as our response to the European Commission’s consultation on a 2015 climate deal. For this report we calculated the carbon budgets remaining for every single country out until 2050. The new carbon budgets announced by the IPCC allow us to update that research to ascribe each country their total carbon budget not just out to 2050, but for all time. This budget breakdowns is provided in full in the attached spreadsheet: SERF IPCC 5AR budgets . A short overview of key countries and country groups is provided below in the table below:

Viewed through the lens of this budgets approach, there is a very real danger that the current piecemeal approach to target setting will lead to rich countries expropriating carbon assets that properly belong to poorer ones. Sustained inaction in some large developed emitters (e.g. North America, Australia) has let them already exceed their fair share of the carbon space and finds them encroaching on the emissions space of other countries without properly compensating them. Indeed, most developed countries are coming rapidly to the end of their budgets and will need to buy emissions rights from developing nations to cost-effectively meet their responsibilities (or meet them at all).

As international negotiations advance towards a 2015 climate deal, countries will naturally strive for the best possible outcome for themselves. To prevent the most political powerful countries from shirking their responsibilities or deflecting them on to other countries, it is essential that civil society keeps questions of fairness and equity at the forefront of the climate negotiations and in the setting of national targets. The budgets approach is a powerful measure of this.