chapter  1
6 Pages

Climate change: The challenge to be met

ByRainer Hinrichs-Rahlwes

Climate change is anthropogenic, manmade. Since the beginning of industrialisation, greenhouse gas emissions and resulting atmospheric concentration have increased dramatically. Longstanding concentrations below 300 ppm (parts per million) increased rapidly, since industrialisation began. Business-as-usual scenarios see the world quickly approaching the threshold of 450 ppm CO2equivalent, which scientists consider to be the upper limit of greenhouse gas saturation of the atmosphere – if we want to limit global warming to a maximum of 2◦C (or 1.5◦C) compared to pre-industrial levels and thus prevent most catastrophic impacts. In recent years, growing evidence was provided that 450 ppm might still be much too high for achieving the 2◦-target (and even more so for targeting a lower temperature rise, which more vulnerable countries hold to be necessary). A new target of limiting greenhouse gas concentration to a maximum of 350 ppm (or lower) is being introduced in the scientific discussion and in the political process. Whereas the lower limit seems to become scientific common sense, it is far from being political consensus and from becoming the new target for the international multi-lateral climate process1. Whereas evidence is growing that greenhouse gas reduction is even more urgent than it was

considered a few decades or only a few years ago, global greenhouse gas emissions are further increasing – particularly in the developing world. Efficiency gains in the industrialised world are being more than overcompensated by increasing energy needs for new technologies. Meanwhile China has overtaken the United States of America as the world’s biggest greenhouse gas emitting country. Other major developing economies – e.g. India, Brazil, Mexico, and the ASEAN countries – are rapidly increasing their greenhouse gas emissions. On a per capita basis, they still have much lower emissions than the industrialised countries in Europe and in particular in North America. But the trend is clear. The more countries reach a certain level of development and resulting industrialisation, the more greenhouse gas emissions will increase – in absolute terms and potentially also on a per capita basis.