Climate scientists will shed new light on climate change mitigation

World-leading climate scientists gather in Garmisch-Partenkirchen, Germany, next week, Sept. 18-23, to present new research on how land areas on the Earth: forests, soils, permanently frozen regions, deserts, croplands and pastures affect the global climate. This major international conference will bring 400 scientists to shed new light on climate change mitigation.

Conference organiser, Academy Professor Markku Kulmala from University of Helsinki, Finland says:

- Humans have commandeered over 75 per cent of the land on the Earth outside of Greenland and Antarctica. How we manage this land this century will be a major factor in whether we can stabilise global greenhouse gas emissions.

Previous work suggests old forests stop growing so they have limited value in removing excess carbon from the atmosphere. Professor Munger and colleagues from the United States will discuss the value of mature forests in storing carbon. This would imply that policymakers should focus on developing newer forests. But the new research to be presented at the conference suggests we should not be so hasty. Contrary to what might be expected, Professor Munger and colleagues found that the 100-year-old Harvard Forest in central Massachusetts has in fact speeded up its carbon intake over the last two decades. This is primarily because of the increase in biodiversity and structural complexity in the forest over time.

- Continued carbon uptake by mature forests is an important benefit to society. We can ensure that old forests continue to take up carbon if we develop policy and management practices that allow these forests to grow undisturbed, Professor Munger concludes.

Other researchers are focusing on how soil affects climate, and have found intriguing links between soil moisture and rainfall. Different soil types (sand, clay, silt) and their ability to retain water can have a significant effect on the occurrence of rainfall and heat waves.

- Changes in soil type can change mean summer temperature by about 2 degrees Celsius because of changes in evaporation rates. Similarly, mean summer precipitation can change by over 20 per cent because of changes in water vapour input into the atmosphere, says Benoît Guillod, a Swiss soil-atmosphere researcher from ETH Zürich.

Also in the Sahel region in West Africa, satellite observations demonstrate that brief changes in soil moisture over areas of just tens of kilometres can influence storm generation. According to Dr Chris Taylor from the Centre for Ecology & Hydrology in the UK, the monsoon can arrive abruptly in the Sahel. The relative timing of planting and the start of the wet season can mean the difference between a good crop and no crop at all.

- Soil types change over time. For instance, deforestation removes organic matter from the soil and, in the long term, can change the soil type substantially and affect storm and rainfall patterns, he says.

Borderless Science panel discussion

An International Panel gathers on Monday, 19 September immediately after the opening keynote session to discuss Borderless Science and the new directions in land-atmosphere research. The Panel Discussion is proceeding by an introduction by the Panel Moderator Professor Pavel Kabat, the chair of International Science Panel of GEWEX (Global Energy and Water Experiment), a core project of World Climate Research Programme (WCRP). The panel members include representatives from NASA, European research and funding organisations, and universities around the world.

Provided by University of Helsinki