• Jenny Kien

Global warming will change rainfall patterns in Israel

As the planet warms, global weather patterns are changing. Noticeable are changing patterns in rainfall. While some regions are experiencing increasing rainfall, the Mediterranean region is already suffering from a decrease in annual rainfall. Yet, despite this decrease in total annual rainfall, the Mediterranean region (e.g., Spain, Italy) is showing a paradoxical increase in extreme daily rainfall.[1] This trend to more extreme rainfall is not significant for Israel and Cyprus yet but the number of rainy days each year with heavy falls (16-64mm) are increasing, while there are fewer days of light rain (0-4mm).

Even this slight change in rainfall pattern can significantly raise the risk of flooding. The floods, not only damage infrastructure but wash out topsoil, leading to increased erosion. Keren Kayemet L’Israel (Israel’s largest NGO developing the forests) is already planting trees whose roots go deep in areas of future flooding in an effort to hold the topsoil.

PikiWiki Israel 6594 2009 flood in Nahal Hadera.jpg

The tendency for some few heavy downpours and less light rain will cause enormous stress for agriculture. Fields will suffer from too little water and then the heavy rains will damage plants and the soil. Changing rainfall patterns are already causing drying in certain tree species. This injures their health and makes them more susceptible to damage by pests which can now kill them.[1]

Comprehensive satellite data has allowed researchers to set up complex models for weather patterns around the globe to predict our weather throughout the century.

These weather models predict that, throughout the 21st century,[1] north and central Israel, will experience up to 40% less rainfall, mainly in autumn, dramatically stressing Israel’s agricultural. In contrast, the Negev desert will see a 40% increase in rainfall in the winter and spring, greatly increasing flooding. Agriculture must plan ahead, relocating much to the south and leaving crops in the north that can survive on little water and are also flood resistant.

[1] Pinhas Alpert, Assaf Hochman, Paola Mercogliano, Hadas Saaroni, Edoardo Bucchignani. High-resolution projection of climate change and extremity over Israel using COSMO-CLM. International Journal of Climatology 2018 112https://www.tau.ac.il/~pinhas/papers/2018/COSMO_projections.pdf

[1] Rami Zaritski, Head of Forest Department, Keren Kayemt L’israel (KKL) (personal communication).

[1] P. Alpert T. Ben‐Gai A. Baharad Y. Benjamini D. Yekutieli M. Colacino L. Diodato

C. Ramis V. Homar R. Romero S. Michaelides A. Manes The paradoxical increase of Mediterranean extreme daily rainfall in spite of decrease in total values June 2002 Geophysical Research Letters https://doi.org/10.1029/2001GL013554

© 2019 כל הזכויות שמורות לגרינפיס ישראל