Conferences, lectures, fieldwork - Scientists are always on the move. Here they open their professional flights and rides in the first half of 2019.

Traveling all over the world is part of science. Here is the committee meeting at the partner university, there the annual conference of a discipline. The range of goals is large: in these weeks, psychologists can head to Bangor, UK for a course on cognitive neuroscience, then fly to a symposium on addiction to Barnstable, USA, and then head straight to Copenhagen for a conference of neuropsychologists. Her fellow physicists can continue their education on a quantum control workshop in Toronto, Canada, then travel to Birmingham for a conference on ultracold atoms, and finally to Warsaw for lectures on time crystals.

Nobody has ever figured out the flying activity in science, even large German universities such as those in Cologne or Munich can not tell how many kilometers are completed in the academic service. At the same time, however, it is known that flights account for around three percent of global climate-damaging carbon dioxide emissions. However, their effect is much greater: "The total climate damage caused by air traffic in Germany is between six and ten percent," says Lars Mönch, head of the pollutant reduction in traffic at the Federal Environment Agency. This is due to the emissions of nitrogen oxides and other substances in high air layers.

A debate on climate-friendly travel is currently not yet conducted, says a spokesman for the Ludwig-Maximilians-University Munich, with 50,000 students one of the largest universities in Germany. However, one observes the trend that especially with flights CO₂ compensation be booked. The German Research Foundation (DFG), the main donor for research projects in Germany, is aware of the importance of climate-conscious travel, says a spokesman. However, the DFG is subject to federal and state travel expense laws: "The first discussions with the federal and state governments on climate-friendly travel have already taken place - and should soon become more concrete within the alliance of science organizations."

One more level above that, at the European Research Council (ERC), the decision on scientific travel is also left to the scholarship holders. There are no requirements, said a spokesman. The ERC will distribute 2.2 billion euros next year, including unspecified travel budgets. Researchers can usually manage these budgets themselves - the cheaper the connection, the more they can travel. Scientists behave like most business people, journalists and vacationers: they choose the cheaper and faster version, and this is often the plane.

"Climate researchers are no better and no worse than other people," says the director of the Potsdam Institute for Climate Impact Research (PIK), Ottmar Edenhofer. His personal emissions balance is far too high, and that is also due to flying, admits Edenhofer. However, Edenhofer does not want to disclose his travels, as does his PIK colleague Stefan Rahmstorf: "It needs political solutions such as a fair CO₂ pricing - such a price would affect all services and goods, including flying."

Stefan Gössling says: "Politicians are called upon to tax flights fairly." He himself hardly flies. The human ecologist researches environmentally friendly travel at the University of Freiburg as well as in Kalmar and Lund in Sweden. Most recently, the United Nations invited him to a climate conference in Brazil - he said.

The French Government acts more determined than the German Government. In early July, she passed a kerosene tax on all flights. A group of French scientists have become active themselves, they call themselves "labos 1.5". The name refers to global warming, which should be kept as low as 1.5 degrees according to the Paris Climate Agreement of 2015. The initiative wants to reduce its emissions even without new laws: for example, by fewer people sitting on committees. Universities should install comfortable video systems. And: travel to conferences should lose importance, especially for the assessment of younger researchers.

For many scientists, this sounds like an impossible requirement, since it is a testimony to the success and excellence of presenting at international conferences. There plans are forged, publications prepared. But how necessary is that really? Stefan Gössling says his own publications are usually created by e-mail exchange: "Anyone who sits more at the desk, instead of flying around the world, can work wonderfully." In a field study with 29 students, he asked how they rate their flights over the past five years. The result: more than half of the trips seemed to them to be unimportant in retrospect.