How quickly is the climate changing? The phenomena known as ‘abrupt climate changes‘ are particularly interesting. Klaus Grosfeld explains what the term means: “In the course of our planet’s history, there has always been climate change. Normally, it has been a very slow process that takes thousands of years. Yet scientific evidence also indicates that there have occasionally been phases in which the climate changed massively within only a few decades.”
That’s troubling news, since, thanks to anthropogenic climate change, the human race may start experiencing precisely these abrupt changes firsthand in the near future. “We believe there are certain points at which the climate system can suddenly switch to a new status,” relates Klaus Grosfeld.
Since no one can know the future, researchers instead look to the past. In the context of the REKLIM focus area ‘Abrupt Climate Change Derived from Proxy Data‘, they are now seeking to identify phases in the Earth’s history that were characterised by these tipping points. Their hope is that, by arriving at a better grasp of past events, they can better predict whether or not the climate change we’re
now experiencing will produce such points.
That’s a highly complex question and can only realistically be answered by pooling the expertise of researchers from different disciplines, which is what REKLIM does. In the search for abrupt climate changes in the past, marine sediments are an important factor: depending on the respective climatic conditions, different organisms live in the water. When they die, they sink and their physical remains become preserved in the sediment. By analysing these sediment layers, scientists can determine when certain organisms lived and what the prevailing climatic conditions must have been at the time.
The AWI geologist Prof Ralf Tiedemann is one of the experts capable of unlocking the sediments’ secrets and has specialised in marine sediments. As he explains, “One problem we now face is that we only have data from a few measuring points, which makes it hard to tell whether specific climate changes were global or only regional. For instance, we have data from the Atlantic and Pacific – but not from Central Europe.”
To remedy this dearth of information, in REKLIM he is collaborating with Prof Achim Brauer from the German Research Centre for Geosciences (GFZ) in Potsdam, who has been working with sediments in lakes for many years – e.g. at Lake Ammer and at several lakes in Italy. Working together, they are comparing their respective information on climate changes with the data that AWI glaciologists and experts from Heidelberg University have gleaned from millennia-old ice cores; after all, three sources are bound to offer more certainty than just one.
Collaboration yields new discoveries But REKLIM has much more to offer. Once new data is generated, it is also discussed with the AWI’s climate modellers, who use it to simulate the climate of the past. This approach has already yielded a number of interesting discoveries: in the phase before the last glacial period, for example, there were apparently warm periods that continued for several thousands of years, but then ‘tipped over‘ into extremely cold phases within just a few decades. In turn, these were followed by long cold phases that were rapidly replaced by warm ones, until the glacial period finally began, covering huge regions of the Northern Hemisphere in ice.
Further, comparing data from marine sediment, lake sediment and ice shows that
during these abrupt transitions, there were also significant changes in ocean currents and the atmosphere throughout the Northern Hemisphere. “Without REKLIM, we could never have arrived at these results,” claims Achim Brauer from the GFZ. “Thanks to the workshops, we have the chance to get to know other researchers and what they’re working on. Moreover, the initiative creates a sense of purpose that truly promotes collaboration; we have a concrete shared mission, which is a bit different than sharing a cup of coffee and talking about ‘maybe doing some work together someday.’”
Comprehensive approach to regional climate change In terms of its scope and collaboration between different disciplines, REKLIM covers an
enormous spectrum of topics. Two examples: in connection with the topic ‘Coupled Modelling of Regional Earth Systems‘, the researchers are working to develop new methods that will allow them to more accurately model the regional effects of global climate change. In turn, the experts working on the topic ‘Modelling and Understanding Extreme Meteorological Events‘ are exploring extreme weather events like hailstorms, which can produce insurance claims amounting to billions of euros – by harming or destroying solar parks, glass roofs, or agricultural crops. One of the key questions is how to adapt if these extreme events become more frequent. “In terms of the diverse range of regional climate aspects that the network addresses and combines, it’s unique in Europe,” says Klaus Grosfeld.
Sharing advances with the public
Further, investigating regional climate change is also – and especially – interesting because it directly concerns people’s day-to-day lives. Accordingly, one of REKLIM’s objectives is to share the latest advances with the public – e.g. through the project ‘klimafit (fit for the climate)‘, which was jointly launched by REKLIM, the WWF and the regional educational institutions fesa e.V. and ifpro in March 2017. According to Dr Renate Treffeisen, klimafit Coordinator at REKLIM and Head of the AWI’s Climate Office for Polar Regions and Sea Level Rise, “The project is intended to disseminate experts’ knowhow to multipliers – architects, farmers, urban planners, teachers, or municipal climate protection managers – through courses offered at community colleges.” In addition to fundamental information on climate change, the courses also offer suggestions on how people living in the respective region can adapt to it. “To date, this is the first project of its kind in Germany,” says Bettina Münch-Epple, Head of Education
at the WWF Germany. “The course draws heavily on the ‘blended learning’ concept. In other words, we not only work with instructors in the classroom, but also with climate experts who can contribute by video live-stream.” This direct communication between the participants and researchers make the course especially appealing. “klimafit” is currently being rolled out in six municipalities across southwest Germany, a region that is already feeling the effects of climate change. “In some regions of Baden-Württemberg, the average temperature has risen by more than 1.5 degrees,” says Bettina Münch-Epple. As she explains, this affects agriculture; further, the number of extremely hot days has increased, as has the frequency of storms and heavy rains. “Last year we tried out the course on a pilot basis in the city of Emmendingen, near Freiburg. The response was so overwhelmingly positive that we’re now confident of the project’s success,” stresses Renate Treffeisen. The goal for the next few years is to gradually establish the courses in further regions of Germany. “Essentially, we hope to create a snowball effect,” says Klaus Grosfeld, “so the topic of climate change reaches every corner of society. A welcome side-effect: this will show the researchers contributing to REKLIM just how important their work is.”
„The Answer to the question of how much money we should spend on climate protection“Bremen and Bremerhaven plan to soon release a new climate change adaptation strategy, which addresses, e.g. protective measures for flooding and heat waves. REKLIM experts helped the authorities define the respective measures. Dr Christof Voßeler, Policy Advisor to the City of Bremen’s Senator for Environment, Urban Development and Mobility, explains why cooperating with external experts is so important.
Mr Voßeler, adaptation strategies are major projects that often involve a wide range of individual measures. Which aspects have to be kept in mind when preparing a city like Bremen for climate change?
As a coastal city, flood protection is naturally the top priority. But we also expect to see an increase in the frequency of heavy rains, which can be especially important for urban drainage and urban planning. Though we enjoy a temperate climate here in northern Germany, we’ll also likely see more and longer heat waves. This aspect, too, involves urban planning: for example, we have to consider how measures like maintaining green areas and fresh-air ventilation corridors can preserve or even improve our current bioclimatic situation, despite the heat. This type of planning involves diverse aspects, and we rely on the support of external experts.
Why do you need external expertise?
As a government office, our job is to provide a sound foundation for important decisions - for decisions concerning which measures to start today in order to safeguard tomorrow, even though the impacts of climate change still can’t be predicted with certainty. Political decision-makers then have to take the information provided and choose how much money we want to spend on protecting our future. For example, it’s not yet clear how noticeable the effects of the rising sea level will be in our region. Thanks to our talks with the REKLIM experts and to their latest findings, we now know that, despite all the ‘X factors‘ in the equation, the sea level is likely to rise more than was expected only a few years ago. If their analyses are confirmed by subsequent data, the state of Bremen can take action to prepare and adapt its flood-protection measures in time.
Wouldn’t it make good sense to simply plan for the ‘worst case scenario‘?
Beim Hochwasserschutz werden bereits sehr weitgehende Risikoszenarien eingerechnet. Generell müssen wir aber bei allen Themen der Klimaanpassung über Jahrzehnte in die teils ungewisse Zukunft planen. Die Anpassung an den Klimawandel steht als Langfrist-Thema zudem im täglichen politischen Diskurs in Konkurrenz zu Themen wie Bildung, Migration oder Kita-Plätzen, die kurzfristig zu lösen sind. Wie viel Geld sollten und können wir heute der Klimaanpassung widmen? Bei der Kostenschätzung und Nutzenbewertung ist das Wissen von außen enorm wichtig, um in der Diskussion eine stichhaltige Abwägungs- und Argumentationsgrundlage zu haben.
The ‘scientific community‘ and the ‘state‘ are two different worlds. How well does the communication work?
Amazingly well! I first learned about REKLIM from its 2015 conference here in Bremen, and I was immediately impressed by how clear and practice-oriented the presentations were. This eventually resulted in much closer contact. That being said, in some ways we do think along different lines than researchers. For example, researchers try to estimate how much the sea level will rise by – and provide a range of potential values. We also focus on the consequences and feasibility of specific measures and ask ourselves how long they can deliver the desired type and level of protection. In addition, aspects like the point at which a given measure needs to be implemented can’t simply be determined on the basis of scientific data. But by now, each of the two groups is fairly familiar with how the other thinks.
- In the REKLIM initiative, experts from nine Helmholtz Centres and several universities are working together to assess the consequences of climate change for regions in Central Europe and e.g. the Arctic.
- One of the REKLIM initiative’s greatest strengths is its interdisciplinary and cross-centre approach. At joint events and workshops, researchers with a diverse range of backgrounds can exchange notes, often yielding new answers to central scientific questions.
- REKLIM experts consider it their duty to share their expertise with society – e.g. through consulting, public climate courses, or online info-portals.
The number of times the website meereisportal.de was accessed between 1 January 2015 and
31 December 2017 - and the number is on the rise. The sea ice portal is a knowledge transfer product of REKLIM and helps to disseminate expertise to the general public. Providing the latest data on the status and extent of sea ice in the Arctic and Antarctic, it is equally popular with private users and researchers.
Those who share their knowledge learn the most
Our planet’s climate system is so complex that it takes the combined efforts of experts from different disciplines to understand it. The Helmholtz Climate Initiative REKLIM achieves exactly that, bringing together geologists, glaciologists and atmospheric chemists, hydrologists and atmospheric physicists, permafrost specialists and modellers. Their common goal: to understand the regional impacts of climate change and share what they discover with the public. (photo: André Künzelmann)
Talking is silver , discussing is golden
The annual REKLIM conferences have long since ceased to be just for scientists: today, nearly 80 percent of the participants are political decision-makers, representatives of government authorities, environmental activists and other important societal actors who turn to the experts for answers to key questions on regional climate change. (photo: Ernst Fesseler)
Climate change needs plenty of venues
When it comes to getting people living in various cities and communities interested in the changes on their doorstep, the team at REKLIM’s managerial office has a number of tricks up its sleeve, like showing films at the Berlinale, implementing media projects together with students, providing information for political decision-makers, and working with project partners to offer “klimafit” – a community college course intended for anyone who wants to know what the future holds in terms of the climate. (photo: Bärbel Kosanke)