Zafrir Rinat August 14, 2020

When changes are examined only for the summer months, estimates are that average temperatures may rise by as much as six degrees, study shows

The average temperature in Israel will rise by four degrees Celsius compared to average temperatures over the last thirty years, unless steps are taken around the world to mitigate the climate crisis, a study shows.

The assessment was published by the Israel Meteorological Service in its latest update, published this week, which includes trends of temperature change expected to take place by the end of this century. In a less severe scenario, the rise in average temperatures will be by 1.8 degrees. By mid-century, temperatures are expected to increase by 0.9 to 1.8 degrees, depending on the scenario that transpires.

The Meteorological Service analysis is based on two scenarios prepared by the UN’s Intergovernmental Panel on Climate Change. One scenario is based on business as usual, with no significant action taken to mitigate the climate crisis, mainly by reducing the emission of greenhouse gases. The second scenario is less severe and assumes that some action is taken, gradually reducing the atmospheric concentration of these gases.

One must remember that some rise in temperature is expected in any event, since the cumulative concentration of gases already in the atmosphere will continue for many years, impacting the warming process.

The Meteorological Service compared these forecasts with a baseline of average temperatures in Israel between 1988 and 2017. These were obtained from 24 stations across the country.

Based on this analysis, the conclusion is that in a worst-case scenario, Israel will get warmer by four degrees by the end of the century, with half of that occurring by mid-century, with a less severe scenario suggesting up to two degrees of warming. When changes are examined only for the summer months, estimates are that average temperatures may rise by as much as six degrees in the more severe scenario and by three degrees in the more moderate one. 

In comparison, another study published last year by researchers from Tel Aviv University, headed by Prof. Pinhas Alpert, suggested that temperatures in Israel would rise by 2.5 degrees by the end of the century. That analysis, published in the Journal of Ecology and Environment, was based on eight climate models used around the world and on the two scenarios also referred to by the Meteorological Service.

Based on previous studies by the Service, average temperatures in Israel rose by 1.4 degrees between 1950 and 2017, with most of this increase occurring over the last thirty years. This period also saw a rise in the frequency of hot days and nights and a decrease in the frequency of cold ones. This trend is expected to continue in the future, increasing the heat stress Israelis will have to contend with. 

Another study by the service that was published a few weeks earlier looked at the frequency of extreme heat events occurring not in the summer (not between July and September). Such an event is defined as four consecutive days in which the daily high is not less than 33 degrees. The study looked at what can be expected between 2020 and 2099, using 15 different models. It also referred to the two scenarios envisaged by the international team.

The conclusion was that such heat waves which until now occurred twice a decade would now occur once a year, using the less severe scenario. The harsher scenario has this occurring twice a year, increasing to six or seven days on average.

In recent weeks, several steps have been taken in Israel with the aim of improving ways to contend with and prepare for the climate crisis. The Energy Ministry announced a plan to increase the use of renewable energy for the generation of electricity, so that 30 percent of electricity generated will depend on renewable energy sources by the end of the decade. According to environmental groups this is too low a bar, and 40 percent is definitely achievable. 

The Tel Aviv-Jaffa municipality has presented a plan for preparing with the climate crisis. The Energy Ministry has adopted the conclusions of a comprehensive study prepared by the OECD regarding Israel’s preparedness for such a crisis. This includes recommendations regarding housing, transportation and energy production, which will assist Israel in reducing the emission of greenhouse gases.