Neue Studie: Der Zustand des Waldes in den USA hat sich in den letzten Jahrzehnten verbessert

Noch vor 6 Jahren weinten wir alle um die Wetter als der Focus (2010) warnte:

Klimawandel: Eidechsen sterben aus
In siebzig Jahren könnten bis zu 20 Prozent aller Eidechsenarten weltweit verschwunden sein. Den Grund dafür ermittelten Wissenschaftler mithilfe eines neuen Modells.

Ärgerlich, in siebzig Jahren werden die meisten von uns tot sein, so dass wir die Behauptung gar nicht überprüfen können. Außerdem wissen wir mitlerweile, was wir von ‚Modellen‘ halten müssen. Kein einziges Modell hat die seit mittlerweile 17 Jahren anhaltende Erwärmungspause angekündigt.

Eidechsenfreund können nun aber aufatmen. Eine neue Studie bescheinigt bestimmten Eidechsen eine viel stärkere Widerstandskraft gegen klimatische Extreme. Hatte man die flinken Burschen wohl lange unterschätzt… Die australische James Cook University berichtete am 15. Januar 2016 in einer Presemitteilung über die überraschenden Ergebnisse:

Weather-worn lizards might adapt to new climates

James Cook University scientists have found lizards exposed to rain, hail and shine may cope better with extreme weather events predicted as a result of climate change than their fair-weather cousins.

A new study by JCU PhD student Anna Pintor, published in the journal Ecological Monographs, is one of the first to test the Climatic Variability Hypothesis (CVH) – which proposes that animals living in environmentally variable areas should be able to tolerate more environmental fluctuations as a result. This idea is a key assumption of the controversial Rapoport’s Rule – which states that a species at higher latitudes with variable weather conditions leads to the evolution of wider environmental tolerances which leads to a requirement for a larger range size. Ms Pintor, along with supervisors Professor Lin Schwarzkopf and Professor Andrew Krockenberger from the Centre for Tropical Biodiversity and Climate Change, used three groups of Australian skinks for their analysis. 

Their results confirm, in all three groups, that species living in regions with greater temperature variability have both greater environmental tolerances and wider ranges – both in terms of latitude and altitude. Andrew Krockenberger explains the importance of this result to advancing scientific thought “The literature is full of examples of species that do and don’t fit Rapoport’s rule,” he said.  “We’ve shown what is important is the actual underlying mechanism – that species that can deal with a high degree of variability at a single site also end up with more extensive geographic ranges. “Arguing about whether or not Rapoport’s rule is valid is irrelevant and misses the point – let’s start making sure we understand the underlying process instead.”

Lead author Anna Pintor said if we want to understand impacts of climate change in the future, we need to know how species‘ current distributions come about it the first place. “Understanding underlying mechanisms like the CVH is one way to do that, but we need to do a lot more before we can tell exactly how species will be impacted and how to best help them deal with climate change.”


Eine im März 2016 im Fachblatt Forest Ecology and Management erscheinende Studie von Loehle et al. bescheinigt den Wäldern in den USA ein gutes Gesundheitszeugnis, wobei Schäden der Vergangenheit allmählich repariert wurden:

Physiological and ecological factors influencing recent trends in United States forest health responses to climate change
The health of United States forests is of concern for biodiversity conservation, ecosystem services, forest commercial values, and other reasons. Climate change, rising concentrations of CO2 and some pollutants could plausibly have affected forest health and growth rates over the past 150 years and may affect forests in the future. Multiple factors must be considered when assessing present and future forest health. Factors undergoing change include temperature, precipitation (including flood and drought), CO2 concentration, N deposition, and air pollutants. Secondary effects include alteration of pest and pathogen dynamics by climate change. We provide a review of these factors as they relate to forest health and climate change. We find that plants can shift their optimum temperature for photosynthesis, especially in the presence of elevated CO2, which also increases plant productivity. No clear national trend to date has been reported for flood or drought or their effects on forests except for a current drought in the US Southwest. Additionally, elevated CO2 increases water use efficiency and protects plants from drought. Pollutants can reduce plant growth but concentrations of major pollutants such as ozone have declined modestly. Ozone damage in particular is lessened by rising CO2. No clear trend has been reported for pathogen or insect damage but experiments suggest that in many cases rising CO2 enhances plant resistance to both agents. There is strong evidence from the United States and globally that forest growth has been increasing over recent decades to the past 100+ years. Future prospects for forests are not clear because different models produce divergent forecasts. However, forest growth models that incorporate more realistic physiological responses to rising CO2 are more likely to show future enhanced growth. Overall, our review suggests that United States forest health has improved over recent decades and is not likely to be impaired in at least the next few decades.

In den Highlights zum Artikel heißt es:

  • We review information on US forest health in response to climate change.

  • We found that trees are tolerant of rising temperatures and have responded to rising carbon dioxide.

  • No long-term trends in US drought have been found in the literature.

  • CO2 tends to inhibit forest pests and pathogens.

  • Projections of forest response to climate change are highly variable.

Mit Dank an WUWT.


Der NASA-Klimawissenschaftler und ehemalige Astronaut Piers Sellers (60) gab kürzlich bekannt, dass er unter Bauchspeicheldrüsenkrebs im 4. Stadium leidet. Wieder einmal scheint der heimtückische Krebs ein Leben vorzeitig zu beenden. Wir wünschen Sellers und seiner Familie Stärke in dieser Phase.

Leider nutzte Sellers die Situation, um die Ideologie der Klimakatastrophe zu befeuern, indem er Krebs und Klimakatastrophe in einem Artikel am 16. Januar 2016 in der New York Times miteinander verbandelte:

Cancer and Climate Change
[…] It’s doubtful that we’ll hold the line at 2 degrees Celsius, but we need to give it our best shot. With scenarios that exceed that target, we are talking about enormous changes in global precipitation and temperature patterns, huge impacts on water and food security, and significant sea level rise. As the predicted temperature rises, model uncertainty grows, increasing the likelihood of unforeseen, disastrous events. All this as the world’s population is expected to crest at around 9.5 billion by 2050 from the current seven billion. Pope Francis and a think tank of retired military officers have drawn roughly the same conclusion from computer model predictions: The worst impacts will be felt by the world’s poorest, who are already under immense stress and have meager resources to help them adapt to the changes. They will see themselves as innocent victims of the developed world’s excesses. Looking back, the causes of the 1789 French Revolution are not a mystery to historians; looking forward, the pressure cooker for increased radicalism, of all flavors, and conflict could get hotter along with the global temperature. Last year may also be seen in hindsight as the year of the Death of Denial. Globally speaking, most policy makers now trust the scientific evidence and predictions, even as they grapple with ways to respond to the problem. And most Americans — 70 percent, according to a recent Monmouth University poll — believe that the climate is changing. So perhaps now we can move on to the really hard part of this whole business.

Ganzen Artikel in der New York Times lesen. Siehe auch Lubos Motls Kommentare hier.