{"id":1204,"date":"2018-05-18T10:30:04","date_gmt":"2018-05-18T09:30:04","guid":{"rendered":"http:\/\/blog.creamontblanc.org?p=1204"},"modified":"2022-12-16T11:00:11","modified_gmt":"2022-12-16T10:00:11","slug":"climate-in-the-alps-past-present-and-future","status":"publish","type":"post","link":"https:\/\/blog.creamontblanc.org?p=1175","title":{"rendered":"Climate in the Alps: past, present and future"},"content":{"rendered":"

It\u2019s Paleoclimatology Tuesday! Our last Science Sandwich was focused again on climate, but this time exploring how scientists can use the climate of the past to help them predict the climate in the future.\u00a0 Anne Kress, professor and researcher at the Weihenstephan-Triesdorf University of Applied Sciences presented her work at CREA Mont-Blanc<\/strong>.<\/strong> <\/p>\n

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\"\u00c9cosyst\u00e8me
\u00a0Modern alpine landscape with a typical tree-line ecosystem. \u00a0<\/strong>\u00a9 CREA Mont-Blanc<\/em><\/figcaption><\/figure>\n

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Despite it being one of the first beautiful spring days of the season, nearly a dozen curious citizens resisted the urge to go outside, and joined us at the Mont-Blanc Observatory for lunch. Amid friendly banter, everyone prepared their picnic and got in place for the 2018\u2019s 4th<\/sup> Science Sandwich.\u00a0\u00a0 At 12:30, Anne Kress opened her presentation in a nearly perfect French with a slight German accent.\u00a0 Climatologist and professor at the Weihenstephan-Triesdorf University of Applied Sciences in Freising, Germany, Dr. Kress set out to answer a question that many of us non-climatologists have:\u00a0 how is it possible to know what the climate was like in the past? And perhaps even more perplexing: how can we predict that the climate will be like in the future?<\/p>\n

Paleoclimatology<\/h2>\n

Paleoclimatology is a field that studies past climates and their variations.\u00a0 Anne Kress\u2019 presentation was founded on a body of knowledge accumulated during her PhD in paleoclimatology and more specifically, on the reconstruction of the past climate in Europe.<\/p>\n

Unfortunately, we can\u2019t go back in time to directly observe the climate. However, hidden in the natural landscape out in the world, there are countless indicators that allows us to deduce what climatic conditions were like in years past.\u00a0 Using what are referred to as \u201cproxies\u201d including pollen, tree rings, shells, lake sediment and glacial ice cores, scientists can reconstruct the past.<\/p>\n

The European Larch (Larix decidua<\/em>): Living records of past climate<\/h3>\n

Anne Kress\u2019 research was carried out as part of a European Union project with 39 partner institutions which used a variety of climate indicators to study the European climate.\u00a0 Dr. Kress\u2019 proxy of choice was the European Larch (Larix decidua<\/em>), a tree species which can be found at high elevations.\u00a0 In the Valais region of Switzerland she collected samples of both live trees (sampled at altitude) and dead trees (from beams in old chalets) and then studied the percentages of different stable carbon (C16 and C18) and oxygen (O16 and O18) isotopes in the cellulose.\u00a0 For example, if the climate is hot and dry, the proportion of C18 will be higher in the cellulose.\u00a0 One by one, over the course of three years, over 10,000 samples were analyzed using both manual and automatic processes.<\/p>\n

\"\u00c9tude
Historic climate study thanks to larch tree rings\u00a0<\/strong>\u00a9 AKress<\/em><\/figcaption><\/figure>\n

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Studies of the isotopes found in tree rings revealed that larch trees are especially sensitive to humidity (indicated by carbon isotopes) and the length of exposure to sunlight (indicated by oxygen isotopes).\u00a0 These analyses provided precious information for using climate proxies.\u00a0 Essentially, a very hot and wet climate is much more suitable for human activity and for agriculture, than a hot but very dry climate.\u00a0 These studies indicated that during the medieval period, the climate was somewhat wet, that the \u201cLittle Ice Age\u201d was more dry and cloudy and that more recent warming has coincided with more dry and cloudy climate.\u00a0 Gathering together all of these different elements allows us to understand the past climatic conditions in Europe and help scientists improve models for the future.<\/p>\n

Future climate scenarios<\/h2>\n

Fascinated by this work, and wanting to go further in her research, Anne Kress did a post-doc focused on creating future climate models.\u00a0 With help from her team, she worked on 8 global and 12 regional climate models which can be used in predicting species distribution and envisioning what Swiss and Alpine landscapes may look like in the future.<\/p>\n

\"\u00c9volution
\u00a0Evolution of temperature and precipitation in Switzerland <\/strong>\u00a9 AKress \/ CH2011<\/em><\/figcaption><\/figure>\n

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Climate change models in Switzerland (\u201cCH2011\u201d) are conclusive: all scenarios indicate that over the course of the 21st<\/sup> century, the climate in Switzerland will undergo important changes:<\/p>\n