Interview on the IPCC report: "Hurry!"

Climatologist Astrid Kiendler-Scharr on the 1.5 degree target and the current report

In an interview: Astrid Kiendler-Scharr, Head of the Institute for Energy and Climate Research at Forschungszentrum Jülich © FZ Jülich
Read out

Today, the IPCC has published its special report on the 1.5 degree climate target. The tenor of the report: Hurry! To keep global warming well below two degrees Celsius, rapid and drastic measures are required, the conclusion of the science. Astrid Kiendler-Scharr, Head of the Institute for Energy and Climate Research at the Research Center Jülich, has worked as an expert on the report. She gives her assessment in the interview.

What was your motivation to participate in the IPCC special report on the 1.5-degree goal as an appraiser?

Kiendler-Scharr: What motivates me is the conviction that we have a huge challenge to solve with the climate issue. We must not always think in individual publications and hope that the results will somehow find their way together. Therefore, the IPCC reports are so important because they combine the knowledge of the global research community on climate change. In this way, the scientific facts are made available to the politicians so that they can make the appropriate decisions.

In the Paris Climate Agreement, the international community has agreed to limit global warming to well below two degrees, preferably to 1.5 degrees. Is that still possible?

Kiendler-Scharr: In order to achieve this ambitious goal, we need a major shift in energy technology towards renewable energy sources. That coal and other fossil fuels are not conducive to the climate is completely undisputed - at least in Germany and the majority of other nations. Nevertheless, the urgency with which climate change measures should be taken is not yet clear to politicians and the general public, or the necessary steps have not yet been taken. display

Is the 1.5-degree question the right one to achieve more effective climate protection?

Kiendler-Scharr: Setting a temperature target in any case is a paradigm shift agreed in the Paris Climate Agreement. Previously, the climate issue was discussed from the emissions side: what concentrations of which greenhouse gases can one still emit until a certain limit has been exceeded? These climate goals and their implementation were obviously not a success story.

By 2020, for example, Germany's emissions are set to fall by 40 percent compared to 1990 levels. Now, in 2018, this will be difficult to achieve. It remains to be seen whether the temperature target will be a more powerful one to actually take action or whether it will be seen as a political way out of pushing climate or emissions targets aside,

Climatologist Astrid Kiendler-Scharr explains and comments on the IPCC report on the 1.5 degree target FZ J lich

And how does the paradigm shift affect research?

Kiendler-Scharr: There is clearly an increased expectation of science. It now has to make clear statements as to which atmospheric composition, which greenhouse gas and air pollutant concentrations are associated with which temperature increase. As a result, details receive more attention, such as the effects of long-lived greenhouse gases and short-lived air purifiers. For example, all current calculations show that we need to actively remove CO2 from the atmosphere to avoid a temperature increase above 1.5 degrees Celsius.

How come?

Kiendler-Scharr: CO2 is one of the long-lived greenhouse gases. Once in the atmosphere, it stays as good as forever. Even if CO2 emissions were reduced to zero today, the natural sinks, such as forests and oceans, would be far from sufficient to reduce CO2 emissions significantly in just a few decades. The situation is different with the short-lived trace gases and air pollutants.

What role do these short-lived substances play in climate change?

Kiendler-Scharr: Short-lived climate drivers, such as atmospheric ozone or aerosols, ie suspended particles, have a clearly defined residence time in the atmosphere. If you want to reach the 1.5 or 2 degree target, you have to spend a lot of time on these short-lived materials. Ground-level ozone is formed by anthropogenic air pollutants. Not only is it harmful to humans and the environment, it is also a powerful greenhouse gas. Measures to improve air quality have a direct effect on the climate here.

Are aerosols not considered cool for the climate?

Kiendler-Scharr: Yes and no. For aerosols, the situation is complicated. The totality of all aerosols results in a net cooling, but some types of aerosols, such as Ru, can also have a warming effect. At the same time they act as cloud germs. Clouds, in turn, have a cooling or warming effect depending on composition, time of day and altitude. If we understand these complex relationships better, there is a chance in the near future to achieve success in climate change. This knowledge, in turn, could be used as a transitional phase until the reduction of CO2 has progressed further.

What has to happen at short notice?

Kiendler-Scharr: All processes that increase greenhouse gases should be minimized as far as possible. This includes, for example, industrial production, agriculture or livestock farming. Especially in the developed countries, a fundamental change in our way of life is necessary. We have to feel good if we act sustainably in all areas. This requires a new awareness of our lifestyle based on knowledge and conscience. Politically, a viable path usually leads to subsidies or tax concessions: bike lanes, public transport, storage for renewable energy these are projects where politics becomes active and Climate protection can make it more attractive for everyone.

Will the 1.5-degree special report now available increase the pressure on politics?

Kiendler-Scharr: First of all, it should be noted that the report was requested by politicians. This gives science the chance to enter into a very direct dialogue with politics. In my opinion, the special report reflects very well the current state of scientific knowledge on global warming and the resulting climate effects. Overall, it is an impressive example of the worldwide collaboration of the science community.

However, it is not the job of research to do politics. And that's just as well. Science has presented the facts and pointed out the consequences - the policy must now decide how appropriate solutions can be brought about - whether through the promotion of renewable energy sources and their storage or the active reduction of CO2 from the atmosphere. At any rate, it is not enough to plant a tree once in a lifetime.

The interview was conducted by Brigitte Stahl-Busse of FZ Jülich.

(Forschungszentrum Jülich, 08.10.2018 - NPO)