According to the index, areas with low rainfall may be closer to the red line than previously known.
"How much rain fell" is a key question in any climate discussion, but perhaps there is a more important question? Like any household, the global water economy is based on "income," meaning water that enters the system in the form of precipitation, and "expenditure"—water that leaves it as a result of evaporation in its various forms. The main evaporation flux on land is through vegetation in a process called transpiration. In a studyRecently published B-Nature Communications. Scientists at the Weizmann Institute of Science found that, contrary to what was previously known, as far as fiction is concerned, expenses have an upper and stable limit that does not change under different climate and vegetation conditions.
This discovery of inelasticity on the expenditure side has major implications for the global water cycle. This means that any relatively small shift in rainfall, for example due to climate change, could translate into disproportionate changes in the amount of water available (water yield), i.e. the difference between the water entering the system and the water that evaporates from it. In other words, areas with low rainfall may lose available water resources more quickly, while areas with high rainfall may face an increased risk of flooding and inundation.
"Ecological systems in arid regions, like Israel, are more sensitive than we thought to climate change and are closer to their survival limits."
The research team is led by Dr. Eyal Rotenberg, a staff scientist from the group of Israel Prize laureate for Earth Sciences, Prof. Dear DanThe study was based on long-term data from FLUXNET – a global network of measuring stations from hundreds of sites around the world that has been monitoring the exchange of carbon (CO2), water and energy between terrestrial ecosystems and the atmosphere since the 90s, as well as on climate model projections. Their findings challenge conventional assumptions in the field and indicate that changes in the amount of water available are a more significant indicator of the effects of climate change on ecosystems and water sources than precipitation itself.
"The use of this index shows that ecosystems in arid regions, like Israel, are more sensitive than we thought to climate change and are closer to their survival limit," emphasizes Prof. Yakir. "Humid regions, on the other hand, are more sensitive to flooding."
More of the topic in Hayadan:
