• Jenny Kien

Global warming is changing Israel’s weather – what can we expect in future

We imagine that global warming raises temperatures and reduces rainfall. But global warming causes complex patterns of temperature increases or decreases in different areas, complicated changes in rainfall patterns, and changes in the seasonal temperature patterns. Israel, with its variety of geological forms - coastal plains, mountains and deserts all close together - is a special case and it is impossible to use forecasts from data or analyses from other regions.

When looking at changes in weather patterns, it is important to remember that global warming can’t be seen in year-to-year changes but only as a trend over 10 or more years. The trends are also not simple and there are various forms of analyses which can lead to erroneous results.

One of the most recent analyses published for Israel,[1] in which some of these mistakes are corrected, showed that the major climate change has been a rise in the minimum temperatures not the maximum temperatures. This trend is expected to continue. That is, we won’t have burning hot summers. Instead, summer nights will be hotter and there will be more heat during the morning and evening. This will cause the average daily temperature to rise, even though the maximum temperature doesn’t. So far, winter temperatures have shown no significant trends.

מתוך וויקימדיה באדיבות שמוליק

Satellite data now allows setting up and checking models that predict future weather patterns around the world. Such a model for Israel[1] predicts a general increase in seasonal mean temperatures throughout the country. By 2041–2070 the greatest changes, of ~2.5oC will be in autumn and winter. The minimum temperature will continue to rise more than the maximum temperature, resulting in a rise in heat during both the day and the night. By the end of the 21st century, the summer is expected to be 49% longer, while winter will be 56% shorter. The increased hot, dry period may substantially affect the rainfall patterns, the water table level and water resources generally. The long summers will have a dramatic impact on farming, will increase the risk of fires and increase air pollution.[2]

באדיבות וויקימדיה

[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

[2] Assaf Hochman, Tzvi Harpaz, Hadas Saaroni, Pinhas Alpert The seasons’ length in 21st century CMIP5 projections over the eastern Mediterranean. International Journal of Climatology, March (2018) https://doi.org/10.1002/joc.5448

[1] Yizhak Yosef, Enric Aguilar, Pinhas Alpert Detecting and adjusting artificial biases of long‐term temperature records in Israel. International Journal of Climatology, April 2018 https://doi.org/10.1002/joc.5500

© 2019 כל הזכויות שמורות לגרינפיס ישראל