Lecture : Israël face à un climat qui change

heatwave — גל חום. evaporate — להתאדות. the Mediterranean — הים התיכון. the Kinneret — הכנרת. desalination — התפלה, הוצאת המלח ממי הים. drip irrigation — השקיה בטפטוף.

Ask any grandparent in Israel about summers in the past, and you will probably hear that they were not as hot as they are today. The numbers support this memory. According to Israel's national weather service, the average temperature in Israel has risen by more than one degree since the 1950s, and heatwaves have become longer and more frequent. For a small country that is already partly desert, this is a significant change.

The impact of rising temperatures is felt most strongly in the supply of water. Almost all of Israel's rain falls in the winter months, and almost none falls in summer. When the air is hot, more water evaporates from lakes, rivers and soil, so less of it remains for people, farms and nature. Climate scientists expect a decline in rain in the eastern Mediterranean during this century, although the amount can change a lot from one year to the next. In the past, a series of dry winters pushed the level of the Kinneret, the country's largest lake of fresh water, dangerously low.

Israel's main answer has been desalination: removing the salt from sea water. Since 2005, several large desalination plants have been built along the Mediterranean coast, and today they produce most of the drinking water that is used in homes across the country. As a result, a dry winter no longer has to lead to a national water crisis, and families are no longer asked to count every drop.

Desalination is not a perfect solution, however. The process requires a great deal of energy, and much of Israel's electricity is still produced by burning gas and coal, which adds to the problem of climate change in the first place. The very salty water that remains after the process must also be returned to the sea with care, so that it does not harm the plants and animals that live there. For these reasons, many experts argue that new sources of water must be combined with using water more wisely.

Here, too, Israel has some experience to share. Modern drip irrigation, which delivers small amounts of water directly to the roots of plants, was developed in Israel in the 1960s. Israel also cleans most of the used water from its homes and uses it again on farms, a higher share than any other country in the world. "We cannot control the weather," says Yael Mizrahi, a water researcher, "but we can control how we use what we have. Every litre that is saved today is a litre that will be available tomorrow."

No single technology will solve the problem on its own. Yet Israel's experience suggests that even a country with very little natural water can adapt, as long as it plans ahead and treats water as the valuable resource that it is.