Lehren aus 8000 Jahren Klimageschichte: Wie der Golfstrom die Dürren in Nordamerika beeinflusst

Eine kürzlich in den Medien gefeierte Arbeit postuliert, dass vorindustrielle Klimaschwankungen alle zufällig geschehen würden. Eine Vielzahl von Forschern widerspricht dieser fragwürdigen These vehement. Ein gutes Beispiel kommt von der University of Wyoming (UW), die am 11. März 2019 in einer Pressemitteilung bekanntgab, welche systematischen Zusammenhänge sie im vorindustriellen Klima der vergangenen 10.000 Jahre entdeckt hat:

UW Researcher Connects Dots Among Ocean Dynamics, Drought and Forests

In a time of drastic change, humans look for predictability. A recent study led by a University of Wyoming researcher found that even in dramatically changing climates, mechanisms can be found that predict how those changes will play out. The last ice age was 11,000 years ago and, since then, climates have continuously changed, triggering constant shifts in the landscape.

This study found predictable, traceable connections between changes in how the Atlantic Ocean flowed and operated with centuries-long droughts and changes in forest makeup. Connections like these provide a useful framework for anticipating how climate change will continue to shape the way weather and ecosystems look in the future. “Our study found that, over the past 8,000 years, shifts in the Gulf Stream in the Atlantic led to severe drought in North America,” says Bryan Shuman, a professor in UW’s Department of Geology and Geophysics, who headed up the research that came to these conclusions. “The mechanics of this connection remain today, and the potential for changes in the ocean to lead to severe droughts highlights a serious risk for the U.S.”

“However, the predictability — the strong ability to forecast drought and its impacts — is good news,” Shuman adds. “The study focused on an area of the Atlantic Ocean that is experiencing rapid changes today. We can use that predictability to anticipate similar changes in the future and prepare for them to the best of our ability.” Shuman was lead author of the paper, titled “Predictable Hydrological and Ecological Responses to Holocene North Atlantic Variability,” that was published today (March 11) in the Proceedings of the National Academy of Sciences (PNAS). The journal is one of the world’s most prestigious multidisciplinary scientific serials, with coverage spanning the biological, physical and social sciences. Other contributors were from the University of Wisconsin-Madison, Emerson College and Harvard University. Jeremiah Marsicek, a postdoctoral researcher at the University of Wisconsin-Madison, was co-author of the paper and Shuman’s Ph.D. student. Marsicek graduated from UW in 2017.

The paper focuses on the role of changing ocean circulation in creating droughts in the northeastern United States. Researchers looked at the combined evidence of changing water levels of lakes and changes in makeup of eastern forests to explore the timing and potential triggers for these changes. Lake sediment cores, which track the history of a lake for thousands of years, show that the region has become progressively wetter over the past 11,000 years, but that noticeable droughts interrupted the trend for centuries at a time. Researchers then searched for major changes happening at the same time that could cause the droughts and connected them to major shifts in the Gulf Stream in the Atlantic.

“The paper also is important for two other reasons,” Shuman explains. “One, it shows that forests can change dramatically as climate changes. What tree species grow in a certain area changes quickly as climate changes; and, two, by using and comparing multiple methods and locations, we showed that our results were not a fluke. We can get reliable estimates of how climate has changed in the past, which makes us more confident of how we can predict how climate will change in the future.”

During this study, researchers examined 8,000 years of climate variations and their effects in the North Atlantic region. The currently humid Northeast was once as dry as the eastern Great Plains region, which illustrates how severely climate changes can alter water supplies, he says. The importance of climate change arises from effects on natural resources such as water and ecosystems, the paper says. Diagnosing the predictability of these events in the past can help to anticipate future changes, while also clarifying what is known about climate in the past, according to the paper.

The project was funded by the National Science Foundation (NSF). “Significant environmental changes are taking place on Earth. This paper shows that past changes in ecosystems as different as the Atlantic Ocean and North American forests were linked with one another in important and scientifically predictable ways,” says Matthew Kane, a program director at the NSF. “The ability of science to understand these links and forecast outcomes has significant implications for agriculture, forestry and our nation’s future economic prosperity.”

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Radio-Interview von Patrick Moore auf Breitbart. Greenpeace mag ihren Mitbegründer nicht mehr, da er klimarealistische Ansichten hat. So strich man ihn einfach aus der Chronik von Greenpeace. Zu blöd nur, dass das Internet heutzutage nichts mehr vergisst.

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Michael Krüger im ScienceSkepticalBlog:

Stefan Rahmstorf lässt die Katze aus dem Sack. Deutschlands Anteil an der globalen Erwärmung bis 2100 beträgt max. 0,05 oder 0,1 Grad!

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Nochmal Michael Krüger im ScienceSkepticalBlog:

Vor 7.000 Jahren war es global und lokal weitaus wärmer als heute!

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Russisches Blog Climadrom im Sommer 2019:

According to our source in the Presidium of the Russian Academy of Sciences, our country can become a pioneer of the open discussion of climate skeptics and alarmists.

“In the fall, if the elections to the Russian Academy of Sciences do not prevent us, we plan to convene a meeting of the Council on Climate Problems,” the source specified, “at which we want to open a discussion between supporters of different views.“

„But this is only an intention for now,” the source added.

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Video „Global Warming: Fact or Fiction? Featuring Physicists Willie Soon and Elliott Bloom“

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Artikel aus dem Juli 2019 im Blog ‚Gemeinheiten & Beobachtungen‚:

Wer macht das Klima?

Klima ist bekanntlich eine langfristige Abfolge von Wetter, und Wetter ist etwas, von dem die Wetterdienste gestern noch nicht so genau wussten, wie es heute wird und von dem sie heute vormittag immer noch nicht so richtig wissen, wie es heute Nachmittag wird. Was nicht heißt, dass andere Leute, die von Wetter noch weniger Ahnung haben, nicht genau wüssten, wie das Klima sich entwickelt.

Klima, das geht bekanntlich ganz einfach: das gibt es ein Molekül, das man bei genauem Hinsehen mit bloßem Auge sehen kann, das CO2. Das hat einen kleinen Stempel „Made by Man“ aufgeprägt, wenn es aus Kraftwerken oder Automotoren stammt, und wenn man den dann sieht, weiß man, es wird ernst und heiß. Bis zu 1,5°C könnte die Welttemperatur steigen, was genauer bedeutet, dass es in München demnächst im Winter nicht -5°C kalt, sondern 12°C warm ist und im Sommer statt 30°C gleich 50°C erreicht werden. Also noch mal zum mitschreiben für die, die das jetzt nicht mitbekommen haben: laut bremischen und Berliner Erkenntnissen der Mathematik gilt für die mittlere Temperaturerhöhung.

Weiterlesen im Blog ‚Gemeinheiten & Beobachtungen