Germany's record income of more than 13 billion euros from emissions trading is a good sign for climate protection and the market economy.

Because a price tag for the emission of carbon dioxide (CO2) helps immensely to reduce greenhouse gas emissions.

If expenditure on fossil fuels increases, alternatives become more attractive.

In the European trading system, in which the emission allowances decrease every year, the CO2 price has recently increased significantly: On average over the past year, it was around 80 euros per tonne, three times as high as two years earlier.

So far, European trade has been limited to power plants, large industrial plants and intra-European air traffic, and the national CO2 tax is also limited.

European trade should rightly be expanded and four-fifths of the emissions should come from shipping, road traffic and buildings - even if this happens with restrictions.

The pricing of emissions is the most efficient climate way to keep reduction costs low.