Ambitious targets? Let’s start talking numbers

29 November 2012

By Jonathan Grant

The most frequently cited number in the negotiations in Doha is 2°C.  But discussion of the emissions targets that countries might adopt to achieve 2°C then becomes much more vague and qualitative.  There is talk of ‘increasing ambition’, ‘equity’, and ‘common but differentiated responsibility’ (CBDR if you want another acronym).  Our LCEI model provides a more quantitative picture of the reductions countries need to adopt from 2020 to achieve the 2°C goal:

  1. Countries currently classified as ‘developed’ will need to reduce emissions by 50% on 2005 levels by 2030 to stay on a pathway taking them to 80% reductions by 2050.
  2. This means that emissions reductions by these developed countries should be about 5-6% every year from 2020.  This compares with total reductions of around 5% over five years in the first commitment period under the Kyoto Protocol.
  3. The current group of developed countries accounted for 50% of global emissions in 2005.  The share of emissions from that same group of countries should account for only 25% of emissions in 2050 (by which time most countries will hope to be ‘developed’).
  4. Emissions in developing countries are growing at 6% per year and following a Cancun pathway will be 55% above 2005 levels in 2020.
  5. In aggregate, developing countries will need to limit their emissions to just 11% above 2005 levels by 2030.  Though this would require a 30% reduction on projected 2020 levels.
  6. Given current emissions (and economic) growth rates in developing countries as set out in the Cancun pledges, emissions should peak by 2020 and decline at 3-4% every year in the 2020’s.
  7. Globally, emissions will need to be 20% below 2005 levels by 2030, and nearly 65% below 2005 levels by 2050.

We need to provide the usual caveats with these numbers: they are high level approximations and are based on the LCEI model which makes a series of assumptions.  The numbers also depend on the sharing of the carbon budget between nations and groups of nations – a critical issue in the negotiations.  But the inescapable logic of these numbers is that, because developed countries have a smaller global share of emissions in future, developing countries will need to take significant action to reduce emissions rapidly enough in the 2020s and beyond to keep within the 2 degrees budget.

We probably face at least two more years of largely qualitative discussions. But by COP 21 countries should be discussing quantified targets.  Whether they will still be talking about 2°C remains to be seen.

The 2°C scenario assuming Cancun pledges to 2020 are achieved


[Click image to enlarge]


Jonathan Grant |  Tel: +44 (0)20 780 40693