Until now, however, no one had conducted such a comprehensive analysis of the changes in vegetation productivity in the Alps. Previous studies have primarily focused on the influence of global warming on Alpine biodiversity and changes in the distribution of plant species. The Alps are becoming greener because plants are colonizing new areas and the vegetation is generally becoming denser and taller. "The scale of the change has turned out to be absolutely massive in the Alps," says Sabine Rumpf, lead author of the study and, since February, assistant professor at the University of Basel. Greater plant biomass in three-quarters of the Alps This phenomenon of "greening" due to climate change is already well documented in the Arctic and starts also to be detected in mountains. Over this period, plant biomass above the tree line increased in more than 77% of the observed area. Working with colleagues in the Netherlands and Finland, the researchers investigated the change in snow cover and vegetation using high-resolution satellite data from 1984 to 2021. This is the conclusion of a research team led by Professor Sabine Rumpf from the University of Basel and Professor Grégoire Mariéthoz and Professor Antoine Guisan from the University of Lausanne. Now, the reduction in snow cover is already visible from space but this is by no means the biggest change. So in short, it is this convective overturning of the atmosphere - poorly represented in computer models of global warming - that primarily determines the temperature distribution of the surface and upper troposphere, not radiation balance.Melting glaciers have become a symbol of climate change in the Alps. Evaporation and convection processes in the atmosphere transport heat from the surface to the upper troposphere, where it can be much more efficiently radiated into space since it is above most of the greenhouse-trapping water vapor. Fourth, while the whole Earth is indeed in a state that scientists describe as "radiative equilibrium," where the incoming sunlight equals the outgoing infrared radiation to provide a roughly constant overall temperature, the surface is far from this radiative balance condition.Third, the ways in which clouds and water vapor feed back and ultimately influence the temperature of the Earth are, at best, poorly understood.Water vapor over the Earth is extremely variable, both in space and in time. Second, there is a much more important greenhouse gas than carbon dioxide, namely water vapor.First, the influence of a man-made doubling of the amount of carbon dioxide in the atmosphere is small compared to the Earth's natural cooling rate, on the order of only a percent. ![]() But it is much less certain how or if we will recognize the effects of this increase. Virtually all scientists will agree that a doubling of the amount of carbon dioxide in the Earth's atmosphere should have some effect on the temperature of the Earth. ![]() Because of this, finding the correct explanation for the behavior we observe is complex as well. The atmosphere is extremely complex in its behavior. The result is that the satellite temperature measurements are accurate to within three one-hundredths of a degree Centigrade (0.03 C) when compared to ground-launched balloons taking measurements of the same region of the atmosphere at the same time. The second uses intercalibration and comparison among identical experiments on different orbiting platforms. The first involves actual in-situ measurements of the lower atmosphere made by balloon-borne observations around the world. The temperature measurements from space are verified by two direct and independent methods. Recent claims to the contrary by Hurrell and Trenberth have been shown to be false for a number of reasons, and are laid to rest in the September 25th edition of Nature (page 342). An incredible amount of work has been done to make sure that the satellite data are the best quality possible. In theory, one could argue that the computer models are accurate, and that the real measurements have some problem.
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