Climate researcher: “More measurements needed”
After an unusually warm and dry summer in Sweden the discussion about climate change gained new force. So, what is actually happening to the climate? “More measurements are needed so as to understand regional effects, for instance,” says Anna Rutgersson, professor of Meteorology and adviser to the Vice-Chancellor on sustainability issues at Uppsala University.
As a climate researcher, she is used to people trying to link different weather phenomena – such as the unusually warm and dry summer – to changes in the climate. However, since the climate itself varies a great deal from year to year, it is impossible to make direct links like that.
“But you can say that with a warmer climate there is more likelihood of dry summers like this one.”
Earlier this year a Swedish study showed that there is a strong link between a weakening of the Gulf Stream and warm summer months. The researchers have studied the climate during a period 10,000 years ago when the Gulf Stream was weakened.
“They think that the northern hemisphere will get colder if the Gulf Stream slows down, but their study is interesting because it also demonstrates a link to warmer summers. But there is no evidence that this particular warm summer is due to a slowing of the Gulf Stream,” says Rutgersson.
“We also know that when the ice sheets on Greenland melt, this can affect the North Atlantic Current. But it has not been possible to see any weakening in measurements, so I think that the link to this particular summer is a bit tenuous.”
Uses models and measurements
Her own research is about how the seas and the atmosphere interact and how this affects precipitation patterns, for example. Her research group runs a measurement station in the Baltic Sea and uses both models and measurements in cooperation with other research groups.
When it comes to climate change and the rise in global temperature, it is easy to get a feeling that things are moving extremely fast, but the fact that July was 5 degrees warmer than normal is something completely different from the global temperature increase,” stresses Rutgersson.
“It is a problem that the climate is being changed by emissions of greenhouse gases, but that is actually a relatively slow increase of 0.1–0.2 degrees in 10 years. I think that we should be more afraid of the more unexpected links: for example a strong decrease in the Gulf Stream and major changes in Arctic and Antarctic ice sheets. Once that happens, it is harder to stop the momentum developed.”
Work two fronts
The situation is serious but it is, at the same time, important to avoid disaster thinking and the feeling that it is too late to do anything,” says Rutgersson
“It will not be the end of the world and nature will not be destroyed, but the conditions for human life will be affected. We also have problems here in Sweden such as coastal erosion in Skåne and a greater risk of fires. We must work on two fronts: both reducing our impact on the climate and adapting society to the change in the climate.”
She still thinks that the realisation that climate change is happening impacts on very many areas in Sweden today, even though it is a global problem that must be addressed in various fora for international cooperation. In research our understanding is also increasing, but more measurements are needed to improve the models of the climate in the future.
“The IPPC has produced good scenarios for the future that link emissions to global warming, but needs to do more work to understand regional effects and circulation patterns. The reason why we have has such a warm summer is a high-pressure block that has meant that low pressure flows are not following their usual paths. What is the driver behind the change? How will circulation patterns be affected if it gets warmer? It is important to do more work on this and increase our understanding.”
Interdisciplinary research initiatives
Alongside her research Rutgersson is also an adviser to the Vice-Chancellor on sustainability issues at Uppsala University. At present she is working on starting up various research initiatives, the Uppsala University Sustainability Initiatives, that are linked to the UN's Sustainable Development Goals.
“To be able to address the whole of society, you need to include a broader range of knowledge. One example could be combining knowledge from climate researchers and lawyers or psychologists to create an understanding of what is happening and what we can do about it. We are going to use the whole breadth of Uppsala University to solve problems in society. It is really exciting.”
6 September 2018