Bangkok - A strict global carbon budget between now and 2050 based on a fair distribution between rich and poor nations has the potential to prevent dangerous climate change and keep temperature rise well below 2 degrees Celsius, a new WWF report shows.

The report, called “Sharing the effort under a global carbon budget”, is based on research, calculations and analysis by the consultancy ECOFYS and shows different ways to cut global emissions by at least 80% globally by 2050 and by 30% by 2030 compared to 1990 levels.

“In order to avoid the worst and most dramatic consequences of climate change, governments need to apply the strictest measures to stay within a tight and total long-term global carbon budget,” said Stephan Singer, Director of Global Energy Policy at WWF.

“If governments ‘relax’ the rules according to which they distribute emissions, we will end up in climate chaos. There is no such thing as carbon offset for Planet Earth. We have just one planet and it needs one emissions budget.”

“Ultimately, a global carbon budget is equal to a full global cap on emissions.”

According to the analysis, the total carbon budget – the amount of tolerable global emissions over a period of time – has to be set roughly at 1600 Gt CO2eq between the years 1990 and 2050.

As the world has already emitted a large part of this, the budget from today until 2050 is reduced to 970 Gt CO2eq excluding land use changes.

The report evaluates different pathways to reduce emissions, all in line with the budget. It describes three different methodologies which could be applied to distribute the burden and the benefits of a Global Carbon Budget in a fair and equitable way.

• Greenhouse Development Rights (GDRs), where all countries need to reduce emissions below business as usual based on their per capita emissions, poverty thresholds and GDP per capita.
• Contraction and Convergence (C&C), where per capita allowances converge from a country’s current level to a level equal for all countries within a given period.
• Common but Differentiated Convergence (CDC), where developed countries’ per capita emissions converge to an equal level for all countries and others converge to the same level once their per capita emissions reach a global average.

The report says that by 2050, the GDR methodology requires the developed nations (Annex I) as a group to reduce emissions by 157%. Given that they cannot cut domestic emissions by more than 100%, they will need to finance emission reductions in other countries to reach their total.

The different methods give various options for non-Annex I countries.

While the Greenhouse Development Rights (GDR) method allows an increase for most developing countries, at least for the initial period, the two other methods give less room for emissions increase. Under the C&C and CDC methodology, China – for example – would be required to reduce by at least 70% and India by 2 to 7% by 2050 compared to 1990.

The poorest countries would be allowed to continue to grow emissions until at least 2050 under the GDR methodology, but would be required to reduce after 2025 under the two remaining allocation options.