How global warming makes weather events more extreme – also in Israel

Hebrew U. Climate change expert Dr. Ori Adam explains the connection between rising temperatures and flash floods, after over 180 are killed in Central Europe.

European Commissioner for Justice Didier Reynders speaks with Madeline Brasseur, 37, Paul Brasseur, 42, and their son Samuel, 12, at an area affected by floods, following heavy rainfalls, in Pepinster, Belgium, July 17, 2021 (photo credit: YVES HERMAN / REUTERS)
European Commissioner for Justice Didier Reynders speaks with Madeline Brasseur, 37, Paul Brasseur, 42, and their son Samuel, 12, at an area affected by floods, following heavy rainfalls, in Pepinster, Belgium, July 17, 2021
(photo credit: YVES HERMAN / REUTERS)
The floods that have killed over 180 people in Western Europe represent typical events that the world should expect to encounter more frequently as the temperatures on our planet rise, a top academic said.
And the severity of flash floods is a phenomenon that Israel and the Middle East have experienced in the past and will likely experience in the future.

@meravmichaeli

ממשלה חדשה- מה זה באמת אומר? צפו ותבינו !!! #אמתבפוליטיקה

♬ צליל מקורי - מרב מיכאלי MERAV MICHAELI
 

“It is important to highlight that when we talk about the consequences of climate change, we cannot establish a direct link with an individual incident, including the latest disasters in Germany,” noted Dr. Ori Adam, head of the academic committee of the Hebrew University Climate Science Center. “However, there are specific reasons why climate change makes this kind of event more aggressive.”
The expert explained that as the climate becomes warmer, the same happens to the atmosphere.
“A warmer atmosphere can hold more moisture,” he said. “This means that the water content in the air increases. At the same time, however, the threshold for the rain to start falling also goes up, requiring a more severe anomaly.”
As Adam pointed out, rain does not begin to fall just because the sky is full of water, but rather should be looked at as a form of instability. Some perturbation is needed for it to start, like air moving upwards.
“When air moves upwards, it cools off, and as a consequence it can no longer hold all the humidity,” he said.
However, when the atmosphere is warmer, the change has to be more pronounced for the rain to begin. In the meantime, it accumulates and this mechanism often leads to much heavier downpours.
Rainfall is not the only aspect of flooding affected by global warming.
“Heavy rains are not necessarily a problem if the soil can absorb them,” Adam said. “However, hotter days can make the surface of the ground harder and less porous to water. This means that the water just flows on it, instead of being absorbed. This is something that in Israel we see frequently.
“The East Mediterranean region is perhaps the most rapidly warming-up area in the world,” Adam said.
He said Israel is seeing a rise in temperatures, and that today the climatic conditions in Hadera are the same as the ones in Beersheba 20 years ago. “The trend is expected to continue and reach farther north.”
Adam said the most conservative estimates suggest that Israel has experienced a 0.2-degree increase per decade.
While no clear trends in terms of annual rainfall have emerged, the scientist also pointed out that Israel is just a very limited territory in a vaster region, whose precipitation can be affected by several factors including the proximity to the coast and the presence of mountain ranges.
“We have to look at the broader Middle East to see what is happening.”
Asked about how Israel is responding to the challenges posed by global warming, Adam remarked that in certain perspectives, the country is incredibly advanced.
“Thanks to its desalination technology, Israel has no shortage of water,” he said. “If it wasn’t for it, our situation would be a disaster. In addition, Israel is a leader in other fields, for example in agritech. We can just think of its drip irrigation system.”
On the other hand, there are fronts where the nation remains behind.
“While we have some of the best scientists, the infrastructure and the academic infrastructure are very behind,” he said. “Currently there is not even an institution in the country that is capable of running the most modern climate models, including the Israel Meteorological Service.”