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Meeting the 2 degree target

Press release | 07-12-2009

To limit global warming to two degrees Celsius, the increase in global greenhouse gas emissions needs to have turned into a decrease, by 2020. Even under very stringent climate policy, emissions cannot decrease by more than a few per cent per year. Postponing the target year, for example to 2030, would reduce chances of achieving the two-degree climate target. This is concluded in the report ‘Meeting the 2 °C target; From climate objective to emission reduction measures’ that has been published today by the Netherlands Environmental Assessment Agency (PBL).

Two-degree target

Currently, global temperature is around 0.8 degrees Celsius higher than in the pre-industrial era. Without climate policy, this increase will rise to around 2 degrees by 2050, and to between 2.5 and 6 degrees by the end of this century. The effects on, for instance, sea levels and nature, will increase proportionally with increasing temperatures. Based on scientific data, the European Union and the eight largest industrial countries (G8) announced their ambition of limiting global temperature increase to a maximum of two degrees. In their publication, in systematic order, the PBL shows the consequences of this ambition, both in the short term and the long term, for greenhouse gas concentrations and emissions, for the energy system, and with regard to costs, in various parts of the world.

Greenhouse gas concentrations

To have a reasonable chance of achieving a temperature increase of no more than two degrees, concentrations of all greenhouse gases, in the long term, will need to remain within 400 to 450 parts per million (ppm) CO2 equivalents. For the greenhouse gas CO2, this amounts to a long-term concentration of around 350 to 400 ppm. At the moment, CO2 concentrations are close to 390 ppm, and at the start of the industrial revolution this figure was 280 ppm.

Maximum reduction rate

To achieve a greenhouse gas concentration level of 400 to 450 ppm, global greenhouse gas emission need to be halved by 2050, compared to 1990 levels. The maximum emission reduction rate is no more than a few per cent per year, even under very stringent climate policy. The PBL publication shows that, by 2020, the current increase in greenhouse gas emissions would need to be turned into a decrease. Further delay would lead to diminishing chances of achieving the two-degree target. Earlier, the scientific climate panel of the United Nations indicated 2015 as being the crucial target year.


In order to achieve this decrease in emission levels, developed countries need to bring down their emissions by 25 to 40%, by 2020, compared to 1990 levels. In addition, large developing countries also need to contribute to this effort. The current reduction proposals of the various countries, as presented for the climate negotiations in Copenhagen, are not yet in line with meeting the targets.


The PBL publication shows that the available technical and economic options would suffice for achieving the targets. The costs of reducing greenhouse gas emissions are estimated at 1 to 2% of global annual GDP. The emission reduction could be achieved in various ways, such as through energy savings, the use of sustainable energy, changes in western lifestyles, and by preventing deforestation.


The chances of limiting the global temperature increase to two degrees Celsius, at greenhouse gas concentrations of 400 to 450 ppm, is between 20 and 90 per cent. Therefore, the chance of a temperature increase of above the two degrees, is fairly large. The PBL advises that measures aimed at adaptation to the consequences of climate change take into account the risk of a temperature increase of three to four degrees.


More information

For further information, please contact the PBL Press Office (+31 70-3288688 or persvoorlichting@pbl.nl).