For the first time, the international community will commit to binding and verifiable climate protection targets.
The task now, however, is to negotiate far-ranging agreements on the further development of the Kyoto Protocol post-2012 in order to truly avert dangerous climate change. Taken alone, the Protocol’s impact is almost negligible. Even if the industrialized countries achieve the agreed 5% reduction in greenhouse gas emissions by 2012 compared with a 1990 baseline, this will do little to curb human-induced climate change.
Much more far-reaching emissions reductions are needed in all sectors, including aviation. The kerosene tax currently debated by G7 ministers of finance would be a step in the right direction. Nonetheless, a WBGU study has shown that emissions-based charges on the use of air space by aircraft would be much more effective in terms of desired climate impact than a kerosene tax.
More ambitious targets essential to avert dangerous climate change
Climate policy leeway has further narrowed in recent years. Globally averaged surface temperatures have already increased by more than 0.6 °C since the start of industrialization. A temperature rise of more than 2 °C and a rate of change above 0.2 °C per decade will make hazardous effects of climate change very probable. These effects include, for example, more frequent droughts or heat waves, resulting in crop failures, or rising sea levels, putting coastal areas at risk. Furthermore, the costs associated with climate change are considerable and may well far exceed the expense of protecting the climate.
A temperature rise of 2 °C could already occur if the concentration of carbon dioxide in the atmosphere permanently exceeds 400 parts per million (ppm). The current level stands at around 376 ppm. In the past, carbon dioxide levels rose by around 1.5 ppm per year on average. In the last two years this figure was approximately 2 ppm per annum. There is therefore a danger that the stabilization level required to avert dangerous climate change will be exceeded within the next ten years.
Recent studies have already revealed an accelerated melting of ice shelves in Greenland and parts of the Antarctic. Satellite data indicate that sea levels are currently rising by 3 mm per year – an acceleration compared with the average rise of 1-2 mm per year in the 20th century.
A climate conference in Exeter, to which WBGU science provided substantial input, recently affirmed that dangerous climate change can still be averted, but only if the international community adopts far more ambitious climate protection targets than it has done to date. The key priority must be to achieve a 60% reduction in human-induced carbon dioxide emissions worldwide by 2050 compared with a 1990 baseline. In the Council's view, this means that the industrialized countries will have to reduce their carbon dioxide emissions by at least 20% by 2020. The earlier we invest in climate protection, the lesser the harmful impacts of climate change and the less costly climate protection measures will be. More ambitious emissions reductions are financeable at the global level. In addition to political will, however, these will need innovative approaches towards implementation and financing.
Engaging the emerging countries
Developing countries are increasingly suffering from the effects of climate change, which are impeding the poverty reduction process. In particular, developing and newly industrializing countries such as China, Brazil or India are increasingly contributing to climate change through their emissions of greenhouse gases, so they should also be included in future emissions reduction commitments. At the same time, the industrialized countries have a responsibility to cut their own emissions radically and assist the developing countries to devise sustainable energy policies by stepping up their development cooperation in this area.