Helmholtz-Zentrum Geesthacht, 2016-07-25
http://www.hzg.de/060605/index_0060605.html.en

Interview with Dr. Daniela Jacob about the Web-Atlas and the results of the IMPACT2C-project

In the four-year framework of the EU-project IMPACT2C a team of researchers from twelve European and four Asian and African countries established comprehensive studies about the impacts of a 2°C global warming throughout Europe. The impact studies focused on the sectors of climate, energy, health, agriculture, forestry and ecosystems, water, tourism, coasts and the key vulnerable regions outside Europe. . Dr. Daniela Jacob, director of the Climate Service Center Germany, coordinated the team.

Daniela Jacob © Christian Schmid/HZG Daniela Jacob © Christian Schmid/HZG

The IMPACT2C team highlighted 53 key messages, 43 of which relate to Europe. What are the central findings of the project?
Under a 2°C global warming near-surface temperature increase, most parts of Europe will experience warming greater than the global average. All climate models show the same pattern in this regard. In relation to precipitation, the already known division of a robust pattern of increase in projected precipitation for northern parts of the continent, and a reduction in southern parts, is found. In summer, the precipitation amount in several regions of central and southern Europe may decrease by up to 20%. In contrast, in winter, precipitation amount may increase over large parts of Europe, and in northern Europe by as much as 20%.

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.
What are your two key statements concerning the non-European Hotspots?
Especially Bangladesh and the low-lying islands like Maldives are expected to feel the consequences of climate change. Sea-levels will continue to rise even if temperatures will be stabilised at 2°C. With sea-level rise, storm surges and flooding could occur more frequently even with adaptation measures.

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.
How does IMPACT2C influence the debate at the World Climate Summit (COP21 + CMP11) in Paris, which will take place from November 30th until December 11th 2015?
The IMPACT2C results clearly and distinctly show that global warming of 2°C is going to change many facets of life. This will influence not only Africa, Bangladesh nor low-lying regions and the island states, but these changes will also affect Europe, albeit weaker than the previously mentioned regions. In many regions it is expected to warm up more than 2°C, associated with longer lasting and more frequent heatwaves but also a distinct tendency for increased extreme precipitation events. For large areas of central and southern Europe, an increase of high flow events is projected, whereas the north-sea regions could experience more coastal flooding.

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.

The IMPACT2C web-atlas