Interview with Dr. Daniela Jacob about the Web-Atlas and the results of the IMPACT2C-project
Daniela Jacob © Christian Schmid/HZG
Under a 2°C global warming, there may be an increase in the incidence of extreme events. This applies to extreme precipitation, and also for more frequent, intensive, and longer period heatwaves. Under a 2°C global warming, the number of heatwave events in Europe may double. This has negative impacts for human health. Projections of changes in heat stress mortality show that there will be an increase across Europe, and existing health problems, will be exacerbated by the increased heat during heatwaves.
Changes in climate under a 2°C global warming are the cause for impacts in all sectors and regions studied, with the magnitude of the impacts being different depending on the sector and region of Europe. What is clear, however, is that adaptation measures will be necessary under a 2°C global warming. Furthermore, cases study examples show that the impacts under a 3°C global warming, will be even more severe.
There are however, some sectors and regions which may benefit under a 2°C global warming. For example, summer tourism in central and northern Europe, where increasing temperatures, and more sunshine hours, make these areas more attractive. However, for winter tourism, a 2°C global warming has a negative impact, because the reliability of snowfall for skiing holidays may reduce.
A cross-sectoral analysis where multiple impact metrics in the water, agriculture, ecosystem services, and health sectors were investigated, reveals a strong north-south gradient in the number of identified hotspots, with a concentration of ‘losers’ (areas where negative impacts dominate) in southern Europe and a concentration of “winners” in northern Europe
Under a 2°C global warming the total agricultural production may increase by 30% compared to today. Climate change is seen to have little negative impact for agricultural production as a whole. However, this projected result is based on the assumption of continued improvements in technology. This demonstrates how important it is to consider all components of a system when talking about possible impacts from climate change.
Limiting global warming to 2°C above pre-industrial, would not lead to a halt in global sea level rise, because the slow oceanic response to warming, means that changes in temperature today take a long time to work through the oceanic system. Accordingly, the costs associated with storm surges and flooding will increase in the future, despite the implementation of adaptation measures. The highest projected costs associated with flooding are to be found in nations with a North Sea coast, and cities.
For the Niger River Basin in West Africa as well as for the Blue Nile in the highlands of East Africa, the warming is above the global temperature increase. West Africa could experience a modest increase in rainfall, whereas for East Africa no clear trend is projected. In addition, the results of IMPACT2C show that high flows and flood risks are generally projected to increase in both areas. At the same time agricultural drought events are projected to become more severe and of longer duration in most locations.
As outlined above, this will have an impact on many sectors. Given these clear results, I hope the IMPACT2C project has contributed to the background information on which the discussions are based on during the COP21. It is absolutely necessary to agree on a common 2°C target.