Climate change in Israel - the consequences, the risks - and perhaps also the prospects

In the early nineties of the 20th century, many data were accumulated, which indicated a continuous increase in the concentrations of carbon dioxide (CO2) in the Earth's atmosphere, and at the same time - an increase in the global average temperature

Yeshayahu Braur, Galileo, Issue 98, October 2006

Greenhouse Effect

In the early nineties of the 20th century, many data were accumulating, which indicated a continuous increase in the concentrations of carbon dioxide (CO2) in the Earth's atmosphere, and at the same time - an increase in the global average temperature (see Figure 1 and Figure 2).

The effect of global warming due to the increase in the concentration of 2CO has been called the "greenhouse effect", because 2CO, methane and other gases trap the heat radiation and do not allow it to escape into outer space, similar to what happens in glass or plastic greenhouses.

Since the beginning of the 21st century, much effort has been devoted to researching possible scenarios for the development of warming processes, on a global or regional level, until the end of the century. The dangers of climate change led to the signing of the United Nations Framework Convention on Climate Change (Rio de Janeiro 1992) and the Kyoto Protocol (1997), which were designed to limit and reduce greenhouse gas emissions into the atmosphere, mainly in industrialized countries. A study was also conducted in Israel on the subject of climate change forecasts in our region.

According to the estimates of the International Panel of Experts on Climate Change (IPCC, 2001), which works for the United Nations Environment Program (UNEP) and the World Meteorological Organization (WMO), an average warming of the world of about 1.4 to 5.8 degrees Celsius is expected by the year 2100. Beyond the study Theoretically, there is much evidence that the world is in the midst of a climate change process. This change manifests itself in one or both of the two forms below:

A. A change in the average temperature and/or the average values ​​of accompanying climatic or meteorological characteristics, such as wind strength, evaporation rate, rainfall amounts, etc.

B. Change in the number of extreme events or their intensity. Extreme events can be temperatures much higher or lower than normal for the season, amounts of precipitation, hurricanes (or typhoons or cyclones).

Examples of these changes:

A. In the heat wave that hit Western and Central Europe in the summer of 2003, about 35,000 people died due to temperatures that were 3-4 degrees higher than the multi-year average. Most of the victims were the elderly, infants and the sick, who are unable to withstand an extreme environmental stress such as this.

B. In Italy and Turkey, a decrease in the annual amount of rain was recorded during the last decades. Thus, for example, in southern Italy, in a certain area, a decrease from 600 mm to 450 mm of rain per year was recorded.

third. In the seventies of the 20th century, 15-10% of the continental surface suffered from drought. In 2002 there was a drought in 30% of the continental surface. In Europe and Canada, the increase in the frequency of drought is explained by an increase in temperatures that caused the soil to dry out. In Africa and Asia, the proportion of areas affected by drought has increased due to a decrease in rainfall (US center for atmospheric research, 2004).

Consequences of the greenhouse effect on oceans

During the 20th century, the sea level in the oceans rose at a rate of 2-1 mm per year (about 1 cm per decade). A similar finding was also found in measurements on the coasts of Israel, conducted by the laboratory of the Governmental Society for the Study of Seas and Lakes for Israel in Haifa. The IPCC forecasts (2001) predict that by the year 2100 the sea level will rise at a rate of 10-90 cm. This is due to a combination of thermal expansion of ocean water and melting glaciers in Greenland and Antarctica.

A sea level rise of this approximate rate is already an irreversible process, even if measures are taken to reduce greenhouse gas emissions, due to the tremendous thermal inertia of the oceans. This means: flooding of large cities and populated areas adjacent to the coasts, destruction of surface water systems and salting of groundwater due to seawater intrusion.

It is common to think that the oceans have a huge capacity to absorb carbon dioxide. This is through the photosynthesis of algae, mainly planktonic, and through physical-chemical sedimentation. Indeed, it is estimated that until now the oceans have absorbed about half of the amount of carbon emitted since the beginning of the industrial age (the mid-fifties of the 19th century). However, the absorption capacity of CO2 in ocean water is expected to decrease in the future. This is because the dissolution of the gas in water creates carbonic acid (H2CO3). This weak acid causes acidification (decrease in pH), which in turn results in a decrease in the solubility of carbon dioxide in water. To date, a decrease of 0.1 pH units has been recorded, from 8.2 to 8.1. It is estimated that by the end of the 21st century the pH will drop by another 0.4 units, even if the atmospheric concentration of carbon dioxide is limited.

Such a decrease in pH could result in an exacerbation of the greenhouse effect, even if the current rate of greenhouse gas emissions is maintained. The drop in pH will also negatively affect the rate at which plankton fixes phosphorus and nitrogen, and as a result, the nature of biodiversity in the oceans will also be affected, including the variety of fish and marine creatures that feed on plankton, some of which are of great commercial importance.

Consequences of the greenhouse effect on forests and climate change

A moderate increase in global temperature may lead to increased rates of absorption and fixation of carbon by vegetation, as a result of an increase in the rate of photosynthesis. Carbon storage in the soil will also increase.

Tropical forests currently cover about 10% of the Earth's surface, and contain 40% of its biomass. Apparently, increasing the rate of photosynthesis may moderate the effects of the greenhouse effect. However, there is a fear of drying out and the death of the forests due to an increase in temperature, even if relatively moderate, towards the end of the century. The drying of the forests may cause fires and the release of 2CO into the air in huge quantities, which will accelerate the rate of climate change (Westerling et al. 2006).

points of no return

A warming of 2 degrees Celsius will cause severe disruption to habitats and the economy of developing countries. A warming of 3 degrees Celsius will cause melting of glaciers in Antarctica and changes in the Gulf Stream, which will cause cooling of northwestern Europe.

In 2005, the environmental ministers of the European Union countries adopted a goal according to which the increase in the global average temperature would be limited to 2 degrees Celsius. A goal was also set according to which the concentration of carbon dioxide must be limited to 560 ppm (parts per million), twice the concentration before the industrial age.

However, this is a difficult goal to achieve. According to the forecast of the International Energy Agency, worldwide CO2 emissions will continue and increase by 63% until the year 2030. This means: a global average temperature increase of 0.5-2.0 degrees Celsius until 2050.

In the countries of the European Union there is great concern about the acute consequences of climate change on the economy, society and lifestyles. Dealing with climate change is manifested on two different levels:

A. An international effort to reduce greenhouse gas emissions, primarily carbon dioxide. The Kyoto Protocol of the United Nations obliges the developed countries to reduce by 2012 the emission level of these gases to a level 5% less than it was in 1990, in the hope of stabilizing the climate situation and preventing its worsening. A significant part of European countries will not, apparently, meet this goal. On top of that, the developing economies of Russia, China and India are not committed to these reductions, and will surely add to the greenhouse effect beyond its current level. Even at the current level of greenhouse gas emissions, we are facing a situation where the area of ​​glaciers all over the world is expected to decrease dramatically, the sea level is expected to rise considerably, water currents in the oceans, which affect the global temperature, will change greatly, and in fact there is no way to stop the expected changes.

B. Preparing to deal with the expected climate changes. Most Western European countries are already preparing national plans to prepare for climate change, including aspects of the economy, water, energy, forest fires, and more. Among these countries: Great Britain, France, Italy, Portugal, Norway, Finland and Hungary (see table).

Preparation of European countries for climate change - national plans

Even in the United States, many voices are heard calling for a change in the official policy, which still hesitates to address the threat of climate change. The state of California has already decided to reduce greenhouse gas emissions, in an action plan that will be implemented over the next 50 years.

And what about Israel?

Israel has also recorded, in the last decade, unusual climatic events compared to the records of climate measurements since their beginning in the 19th century. Including:

A. 1998: The hottest summer.
B. 2000: The heaviest snow in the Negev.
third. 2000: the hottest month of July (in Jerusalem until c410).
d. In the last four years, the probability of very hot days in Jerusalem (above C350) has tripled.
God. In the years 2004-2006: the month of March was dry, up to 10% of the multi-year average.
and. During April 2006, record daytime temperatures were recorded (up to C330 in the coastal area). At the end of the month the trend reversed and heavy rains fell (80-50 mm per day in the coastal area).

There are researchers who believe that a climate change trend can be identified in Israel, which goes beyond individual extreme events (see, for example, Alpert et al. 2002). According to them, this trend is reflected in the decrease in the amount of precipitation in the north, in changes in the timing of the rainfall that causes a decrease in the number of rainy days, and in an increase in the number of rain storms as well as in the number of days when temperatures are high in the summer.

In contrast, some believe that the changes found are not significant, or alternatively, do not represent the situation in the entire territory of Israel, but only in limited areas. According to them, a more correct situation picture is of mixed trends or the absence of a trend at all, and it can be stated that there have been no substantial changes in the characteristics of the rain in Israel. These researchers also admit the existence of extreme events, but according to them there have already been such things before, including in the XNUMXs.

Preparing for climate change in Israel (even if they do not agree on everything) is important, even essential, to prevent economic and social damage on a large scale. This is due to the fear of drought events, floods, flooding with sea water, the presence of disease-carrying insects (such as mosquitoes) for more months each year, damage to agricultural crops, and more.

On the other hand, an organized and institutionalized dealing with climate change may lead to technological innovation and the development of concepts, technologies and products that are valuable and useful to Israel and even as export products to countries that are at risk as a result of climate change. As mentioned above, these countries also include rich and established countries, which are of great importance as a market for exports from Israel.

Israel has a long-standing international reputation in the fields relevant to climate change, such as water conservation; technologies for efficient irrigation (such as computerized irrigation, drip, hidden drip); Agricultural crops that can be irrigated with brackish water; technologies for irrigation with marginal water such as effluents (= purified wastewater); afforestation in arid areas; Preventing forest fires (such as through controlled grazing, which reduces the amount of dry material available for ignition).

At the same time, a great deal of knowledge has also been developed in Israel about the physical-chemical composition of effluents and compounds that may harm or impair the possibility of utilizing the effluents, such as cooking salt, boron and more. Following this, a unique legislation and enforcement system was prepared in Israel to reduce the concentrations of harmful substances. This system includes an obligation to avoid the discharge of brines (water with high concentrations of salt) from industrial sources into the wastewater systems. Instead, the brines are discharged into the sea, provided they meet the requirements to prevent pollution of the marine environment. Also, detergents in Israel are limited in the concentration of boron to low levels, also here in order not to harm the possibility of reuse of the effluents.

The warming and drying processes occurring in Europe, as well as in large areas in Asia and Africa, make this knowledge very important for them as well. Western European countries enjoyed until recently a situation where it was possible to sustain agriculture without artificial irrigation. However, today there is already a need for artificial irrigation in southern Italy, and it is possible that such a need will arise in the coming years in southern England as well. Even in countries such as Spain, where the summer is long and dry, the percentage of effluents used for irrigation is much lower than is customary in Israel (65% of the effluents are used in Israel, compared to only 16% in Spain). The continuation of the trend of warming and drying in Europe and Africa will intensify the need to adopt methods and technologies for saving water, for efficient use of water and finding new water sources, including reclamation of effluents.

Israel can, and even should, take advantage of this situation in order to become a regional and even global knowledge center, which contributes to the well-being of the world through teaching and advocacy, and can also generate considerable profits from marketing products and technologies based on this knowledge.

The Israeli government has already decided to invest hundreds of millions of shekels in order to place Israel in a central place in the global water industry, an economic branch that is developing rapidly. The global needs arising from climate change can greatly expand Israel's attractiveness and relative advantage as having decades of proven knowledge and experience in dealing with climate difficulties and water resource shortages, and bring it to a leading place in the world in preparing for, coping with, and adapting to climate change.

Dr. Yeshayahu Braor is the chief scientist at the Ministry of Environmental Protection