17th Swiss Global Change Day - Meeting Report and Conference Documents
On 12 April 2016 the Swiss global change community met for the 17th time on the annual Swiss Global Change Day. About 270 participants attended the event, which offered scientific highlights presented by distiguished researchers as well as a broad overview over current global change research in Switzerland depicted on 77 posters. Furthermore, the conference served Swiss researchers and people from governmental institutions and the private sector to get and stay in contact. There was enough time for discussion and networking in a transdisciplinary manner.
Gregor Leckebusch from the University of Birmingham, UK discussed the question of how climate change may influence winter storms. Extreme mid- latitude winter storms are a major threat for infrastructure and insured losses in Europe. For the formation and tracks of cyclones the atmospheric circulation in general and in particular the polar front is the most important feature in the mid- latitudes. The different phases of the North Atlantic Oscillation (NAO) are a prominent natural mode of variability in atmospheric pressure and affect the heat and moisture transport as well as storm tracks. Observed temperature anomaly trends for Central-Europe are everywhere positive and lead to a moister atmosphere with more energy to intensify storms. Furthermore, higher latitudes (polar regions) are warming faster than lower latitudes, which changes the redistribution of energy from north to south. The formation of storms is thus potentially affected by climate change through these processes. However, there exist gaps in the understanding of driving mechanisms leading to severe event frequency-intensity changes on different time scales from inter-seasonal to multi-decadal. Nevertheless, the known factors are good candidates for understanding large-scale influences on the interannual variability of extreme cyclone occurence. The existing uncertainties with regard to changes in extreme events are crucial to be quantified - for scientific understanding as well as for society. (Presentation Gregor Leckebusch)
In his talk, David Bresch from the ETH showed that natural disasters can damage sovereign creditworthiness and that this situation is aggravated by climate change. It depends on the size and structure of a country if a damage by natural hazards (earthquakes, tropical storms, floods) can be absorbed. For example, some countries have large sectors that are less vulnerable than others. Therefore, a natural catastrophe produces different damages on the economic property values in different countries. Bresch highlighted that natural disasters which can be expected once in every 250 years, can weaken sovereign ratings. There are added potential sovereign rating downgrades due to climate change, especially for emerging and developing sovereigns (Caribbean, Southeast Asia). One way to mitigate economic and rating impacts due to natural disasters is catastrophe insurance. The insurance industry’s reimbursement accelerates the restoration of the damaged assets, such as productive capacity and infrastructure. For future research, Bresch points out that transparency is crucial. While climate models are transparent and open for public access, economy models are still proprietary. (Presentation David Bresch)
Karen O’Brien from the Department of Sociology and Human Geography, University of Oslo (Norway) talked via Skype about taking climate change seriously and what types of transformations are really needed. She showed how the three different spheres of transformation influence each other. Most of our attention is focused on the practical sphere with behaviours and technical responses like less meat consumption or more use of public transport. The political sphere includes norms, regulations, rules, insurance systems and so on. The personal sphere has a strong influence on other spheres – our beliefs, values,worldviews and paradigm on the individual and collective level. For successful transformation to sustainability the highest leverage point is the power to shift paradigm to deal with new challenges. (Presentation Karen O'Brien)
Hubertus Fischer from the University of Berne, Physics Institute & Oeschger Centre for Climate Change Research, showed what we can learn about the 2°C even 1.5°C global warming target from the knowledge of past climate change. Unfortunatley, none of the past climate analogues resembles the current anthropogenic warming in all aspects. CO2 probably wasn‘t as high as today for the last 2.7 Myr (or even for the last 27 Myr) and warmer periods in the late Quaternary were warm for different reasons. However, Fischer states that it is reasonable to assume that at least the response of the Earth System components to a warming is independent of the latter’s cause, and therefore the impacts of earlier warmings can be compared to the current and expected one. So Fischer compared the climate in the Last Interglacial – a reasonable analogue for a 2°C warming – with the climate at the end of 2100 for RCP2.6 that should allow to reach the 2°C target. Fischer examined among others the feedbacks and threats in and to the earth system. He showed that a global warming below 2°C will avoid a runaway greenhouse gas feedback with medium to high confidence as well as the disintegration of large ice sheets (with medium confidence). Fischer pointed out that following a less strict reduction pathway than RCP2.6 (such as RCP4.5) will likely lead to several meters of sea level rise by 2500. (Presentation Hubertus Fischer)
Martin Hoelzle from the University of Fribourg, Department of Geosciences, and from the World Glacier Monitoring Service explained that glaciers belong to the essential climate variables and therefore are relevant, feasible and cost effective for characterizing the climate system and its changes. Nowadays, glacier mass balance results are based on different studies with various methods and show strong differences with large uncertainties in important and large mountain ranges. Hoelzle talked about the need for a glacier monitoring combining traditional measurements with new technologies by using an integrated and multi-level strategy to improve estimates of glacier related variables. He especially pointed out the need for good quality of in-situ measurements to reduce existing uncertainties, coverage of remote sensing data, models relying on a sound process understanding, downscaling approaches for climate models, and the importance of combined analysis of in-situ observations, remotely sensed data and numerical models. (Presentation Martin Hoelzle)
Corinne Le Quéré from the Tyndall Centre for Climate Change, UK, addressed the question of what the Paris agreement has changed for carbon cycle research. From her point of view, the Paris agreement is a great success. However, as she points out, to have the balance between carbon sources and sinks equal to zero – as it is set down in the Paris agreement – emissions need to go down to zero. To reduce emissions, the scientific community should continue to clarify the risks of climate change and pay particular attention to the difference between 3, 2 and
or1.5 degrees of warming. Synergies and trade-offs between climate action and other societal priorities need to be made explicit. Le Quéré then drew the attention to the integrated assessment models suggesting negative emissions in order to achieve a cost-effective limitation of global warming to below two degrees. In practice, this means to capture and store CO2 under the ground. Existing technologies have not yet been demonstrated at the large scale and bear several risks to be evaluated. To close her talk, Le Quéré encouraged the scientific community to raise their voice and communicate their findings outside of academia to achieve the goal of reducing global emissions from now on. (Presentation Corinne Le Quéré)
About 70 posters were presented at the 17th Swiss Global Change Day in the categories Atmosphere/Hydrosphere, Geosphere/Biosphere/Biodiversity, Human Dimensions and Organisations. In the poster session the best posters in the different fields were selected by a jury and honored with a travel award of 1000 CHF each.
The following posters were awarded:
Atmosphere/Hydrosphere (awards sponsered by the ACP, the Commission for Atmospheric Chemistry and Physics, SCNAT):
- Martin Frischknecht (ETH Zürich) presented a poster to ENSO and the fate of coastal production in the California Current System form 1979 to 2015 (Poster Martin Frischknecht)
- Kathrin Fuchs (ETH Zürich) was awarded for her poster "Management matters: Testing mitigation strategy for greenhouse gas emissions on intensively managed grassland". (Poster Kathrin Fuchs)
- Jonas Arnaiz (University of Basel) presented a poster to the question of alpine plants and small statures: Do exceptionally tall forbs differ in biomass and non-structural carbohydrat allocation? (Poster Jonas Arnaiz)
- Magali Matteodo (University of Lausanne) was awarded for her poster to snowbeds that are particularly affected by climate change in the Swiss Alps. (Poster Magali Matteodo)