It is the week of climate policy decisions: On Friday, the Climate Cabinet wants to agree on a lawsuit package. Immediately afterwards, the Chancellor flies to the UN climate summit in New York to present the German plans there. DirkMessner, Chairman of the German Advisory Council on Global Change, Director of the Institute for Environment and Human Security at the United Nations University in Bonn and President of the Federal Environment Agency from January 2020, has spent his life researching on environmental and development issues. In the interview, he talks about what has to change now.

ZEIT ONLINE: Mr. Messner, on Friday, the Federal Government wants to submit its climate protection plans, and for weeks outranking key players with ever new proposals. Only a few examples are being discussed, such as a reduced VAT on train journeys, a wreckage bonus for oil heating systems and a price for CO2 emissions. What do you make of it?

Dirk Messner: At last, the entire Cabinet deals with climate issues! This is important. I find it very well that the interest in climate issues is now not only very strong in society, as the Fridays For Future demonstrations and the current poll ratings show, but also in politics. However, whether the measures are sufficient to actually carry out serious climate protection must be seen, because we have to fundamentally rebuild central infrastructure and economic sectors.

The transition to a greenhouse gas-neutral economy is not a harmonious undertaking - it would be naive to believe that.

ZEIT ONLINE: At the moment seems from the many small detail proposals yet to create a big change plan. In central points, the Union and the SPD are still not in agreement, for example on CO2 pricing.

Messner: The transition to a greenhouse gas-neutral economy is not a harmonious undertaking - it would be naïve to believe that. Of course there's a lot of stuff for conflict in that. If we want to land zero emissions in 2050, that's extremely demanding: we have to cut CO2 emissions by half every decade. It's understandable that the individual sectors - energy, agriculture, mobility - would like to see each other do more, so they get more time themselves. The bumpy political process is an expression of this. But the important thing seems to me: Now everyone is sitting at the table and have to deliver.

ZEIT ONILINE: Which suggestions do you find particularly good?

Messner: We finally have a comprehensive discussion about mobility. It resembles the debate about energy that we had ten years ago. At that time, the energy transition began with the goal of a zero-emission energy economy - that was initially considered madness. But then the change came on.

China relies on electric vehicles, the pressure on the German automotive industry is high.

And that's exactly what we're talking about zero-emission mobility. China relies on electric vehicles, so the pressure on the German automotive industry is high. Until the diesel scandal, companies have relied on their ability to continue their old business model, but that's not possible anymore. Climate protection is suddenly important in society - as the sector responsible for 20% of greenhouse gas emissions can not continue as before.

ZEIT ONLINE: Do the companies themselves see it that way?

Messner: Most people have understood that their business will only work with climate protection in the future. Even the most difficult sectors are moving: steel, aluminum, cement. New business models are emerging and climate-friendly investments are being prepared. That's how it should be. But the companies are also trying to buy time for the conversion. Politicians must be careful that this is not at the expense of the climate goals.

ZEIT ONLINE: What must necessarily be on Friday in climate legislation?