Universität Göteborg: Trinkwasserversorgung auf dem Tibetplateau ist auch in den kommenden Jahrzehnten gesichert

Vor kurzem verstarb der bekannte Klimaskeptiker und Geologe Bob Carter. In zahlreichen Nachrufen wurde seine Arbeit gewürdigt. Trauersituationen wie diese offenbaren jedoch auch den wahren Charakter einiger Zeitgenossen. Der Klimaaktivist William Connolley freute sich in seinem Blog diebisch über Carters Tod:

Science advances one funeral at a time
Actually a new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it, but I’m allowed to paraphrase in titles. And anyway [Max Planck] said it in German, naturally. Today brings us news of another such advancement in science, with the reported death of Robert Carter.

Was für ein kranker Geist, William Connolley. Über seine Wikipedia-Fälschungen hatten wir an dieser Stelle bereits einmal berichtet (“Klima-Fälscher Connolley: Der Mann, der unser Weltbild umschrieb“).

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Der Klimaforscher Kevin Trenberth erklärte am 20. Januar 2016 in der Washington Post, dass er nicht davon ausgehe, dass das Jahr 2016 wärmer als das Vorjahr wird. Der El Nino erreicht gerade seinen Höhepunkt und wird später nicht die Wärme beitragen können, die für einen neuen Rekord gebraucht werden würde:

“My guess is that 2016 may not be warmer than 2015,” said Kevin Trenberth, a climate change and El Niño expert at the National Center for Atmospheric Research. He thinks the current El Niño may already have begun to peak (or have peaked) and thus that the second half of 2016 may cool down again somewhat.

 

 

 

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Eiskerne aus der Antarktis und Grönland liefern wichtige Klimaarchive der letzten Millionen Jahre. Unter anderem messen die Forscher an den Kernen CO2- und Methan-Konzentrationen. Die große Frage: Kann sich die Gaszusammensetzung der Atmosphäre über einen so langen Zeitraum unverändert im Eis erhalten, trotz Bewegung des Eises? Eine neue Studie hat nun  herausgefunden, dass sich die Methankonzentration in den Eisbläschen durchaus im Laufe der Zeit ändern kann. Am 15. Januar 2016 berichteten Rhodes et al. im Fachblatt Climate of the Past Discussions über Artefakte, die man lange nicht für möglich gehalten hatte:

Local artifacts in ice core methane records caused by layered bubble trapping and in-situ production: a multi-site investigation
Superimposed on the coherent and major atmospheric changes in trace gases revealed by ice core records, local high frequency, non-atmospheric features can now be resolved due to improvement s in resolution and precision of analytical techniques. These are signals that could not have survived the low-pass filter effect that firn diffusion exerts on the atmospheric history and therefore do not result from changes in the composition of the atmosphere at the surface of the ice sheet. Using continuous methane (CH4) records obtained from five polar ice cores, we characterize these non-atmospheric signals and explore their origin. Isolated samples, enriched in CH4 in the Tunu13 (Greenland) record are linked to the presence of melt layers. Melting can enrich the methane concentration due to preferential dissolution of methane relative to nitrogen, but we find that an additional in-situ process is required to generate the full magnitude of these anomalies. Furthermore, in the all ice cores studied there is evidence of reproducible, decimetre-scale CH4 variability. Through a series of tests, we demonstrate that this sign al is an artifact of layered bubble trapping in a heterogeneous-density firn column; we term this phenomenon ‘trapping noise’. The magnitude of CH4 trapping noise increases with atmospheric CH4 growth rate and seasonality of density contrasts, and decreases with accumulation rate. Firn air transport model simulations, accounting for layered bubble trapping, are in agreement with our empirical data. Significant annual periodicity is present in the CH4 variability of two Greenland ice cores, suggesting that layered gas trapping at these sites is controlled by regular, seasonal variations in the physical properties of the firn.

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Rückblick: Im Jahr 2009 schürte die Frankfurter Rundschau kräftig Klimaangst:

Klimawandel Tibets Gletscher schwinden
Forscher befürchten eine massive Wassernot in asiatischen Ländern. Von der Dürre wären Milliarden Menschen betroffen.

Sieben Jahre Forschung später. Eine neue Studie konnte die wilden Schreckensvisionen nun entkräften. Laut Modellierungen wird die Wasserführung der Flüsse auf dem Tibetplateau in den kommenden Jahrzehnten sogar zunehmen. Die Trinkwasserversorgung ist also gesichert. Endstation für den Klimaalarm. Im Folgenden die entsprechende Pressemitteilung der Universität Göteborg vom 1. Januar 2016:

Water supplies in Tibet set to increase in the future

The Tibetan Plateau has long been seen as a “hotspot” for international environmental research, and there have been fears that water supplies in the major Asian rivers would drastically decline in the near future. However, new research now shows that water supplies will be stable and may even increase in the coming decades.

A report by the International Panel on Climate Change (IPCC) from 2007 suggests that the glaciers in the Himalayas will be gone by 2035. This statement was questioned and caused a great stir. “This mistaken claim and the subsequent debate pointed to a need for a better understanding of the dynamics of climate, glaciers and future water supplies in the region,” says Deliang Chen, Professor in the Department of Earth Sciences at the University of Gothenburg.

Since the statement by IPCC in 2007, the Tibetan Plateau has been a focus of international environmental research. A research group led by Professor Deliang Chen at the University of Gothenburg, in close collaboration with researchers from the Institute of Tibetan Plateau Research at the Chinese Academy of Sciences, headed by Professor Fengge Su, has studied future climate change and its effect on the water balance in the region. The great Asian rivers have their source on the Plateau or in the neighbouring mountains. The researchers recently published a study in Global and Planetary Change which modelled the water flows upstream in the Yellow River, the Yangtze, the Mekong, the Salween, the Brahmaputra and the Indus. The studies include both data from past decades and simulations for future decades. The results show that water flows in the rivers in the coming decades would either be stable or would increase compared to the period from 1971-2000.

The Tibetan Plateau is the highest and most extensive area of high land in the world, and what happens there affects water resources for almost a third of the world’s population. Dr. Tinghai Ou, who was responsible for the climate projections in the study, has commented that increased precipitation and meltwater from glaciers and snowfall are contributing to increased water flows in the region. “This is good news because social and economic development in the surrounding areas, including China, India, Nepal and other countries in Southeast Asia, are closely tied to climate change and access to water. But the fact that the glaciers are shrinking in the region could be a concern in the longer term, and we must keep a close eye on what is happening with global warming,” says Professor Deliang Chen.

More about the study here:
Su, F., L. Zhang, T. Ou, D. Chen, T. Yao, and K. Tong, Y. Qi, 2016: Hydrological response to future climate changes for the major upstream river basins in the Tibetan Plateau, Global and Planetary Change, 136, 82-95, doi:10.1016/j.gloplacha.2015.10.012.
Link to the published study