Global warming is exacerbating atmospheric chaos in unpredictable ways, science warns, and Tel Aviv just bore the brunt
Ruth Schuster | Jan. 7, 2020

The 2020s is shaping up to be the decade of climate change impact, and Israel began it with a bang – of thunder. The nation was shocked when two adults drowned in an elevator in Tel Aviv that shorted in a flooded basement on Saturday. Low-lying roads, some of them major arteries, became impassable as more than 20 percent of the city’s average annual precipitation fell in the space of three hours, breaking rainfall records. Two more people died up north on Sunday after their cars were swept away by flooding streams.

Forecasters had predicted the stormy weekend and, as usual, warned Israelis to avoid trekking through riverbeds. But Tel Avivians hadn’t expected anything of such dramatic magnitude.

Though substantial “once-in-50-year” floods seem to happen in Tel Aviv roughly once every 10 years in recent decades, it is unfair to accuse the municipality of blitheness or being unprepared. Government disaster-preparedness policy everywhere must be based on probabilities and reasonability (not to mention affordability). No city can reasonably invest huge proportions of precious taxpayer resources in building expensive new drainage systems for extremely rare events.

The probability of a such a storm striking Tel Aviv has not been high. But it has clearly been mounting. One key problem with preparing is to know what to prepare for, and we don’t, not reliably. The entire region of North Africa and the Middle East is undergoing desertification yet right now, we have flooding.

Over 90 millimeters (3.5 inches) of rain fell on the city on Shabbat, most of that between 11 A.M. and 1 P.M., the municipality says. From Saturday morning to Sunday morning, 103 millimeters of rain fell in Tel Aviv.

Also in favor of city hall, Tel Aviv was exceptionally hard hit. Hadera, just 50 kilometers (31 miles) up the coast, had a tenth of Tel Aviv’s rain this weekend, exactly 10 millimeters – barely enough to rinse the car. Ariel in the West Bank had 45 millimeters, Be’er Sheva less than 17 millimeters and the hilltop town of Zichron Yaakov was almost entirely spared with less than 7 millimeters.

Normally, the average annual rainfall in Be’er Sheva is 230 millimeters, so this weekend did bring comparatively heavy rains. But nothing unmanageable.

Elsewhere, however, flooding in low-lying parts was reported from the Negev to the north, and snow fell in the Golan Heights and on Mount Meron in the Galilee.

Sunday morning has brought a hiatus in the south and center of the country at least, but the storms are expected to resume Tuesday and to last roughly all week.

Chaos in the atmosphere

Israelis could be forgiven for becoming skeptical of short-term weather forecasts, which seem to be increasingly unreliable. They are, actually.

Last March, Swedish scientists reported in Geophysical Research Letters what the masses had begun to suspect: The ongoing climate changes make it harder to accurately predict certain aspects of weather, looking ahead a few days to a couple of weeks. Warnings in Israel to take care because “bad weather” threatens, and to avoid trying to ford flooding riverbeds, for instance, are routine and may not set off adequate internal bells when the danger suddenly becomes acute.

Weather forecasting has always been plagued by a core difficulty: The atmosphere is chaotic. Specifically, the Stockholm University study warns that the worst increase in uncertainty will be about sudden summer downpours in the northern hemisphere.

Temperature will apparently be easier to predict with relative accuracy, the researchers say, while local rainfall will be harder to predict.

Israel generally doesn’t have a problem with sudden summer downpours. Local precipitation is seasonal and comes in winter.

But the fact deranging forecasters is that climate change and global warming are taking certain parameters beyond ranges we know.

Climatic aberrations have happened during recorded history, including extremes such as the Medieval Little Ice Age that stretched from about the year 1300 to 1870: almost 600 years. Yet it was an aberration, albeit a protracted one to us short-living humans, not a new normal.

Now, weather patterns that had been at the far end of extremes are becoming more common – for instance, heat waves. Their very name indicates rarity, but how surprised is anybody anymore at reports of record temperatures? Part of Australia’s extreme wildfire problem right now is the drought and record heat, all associated with climate change.

When it rains, it will pour

Global warming projections are sure of only one thing: There will be multiple impacts, and we don’t know how they will play out. But there is a general consensus that in the decades to come, extreme weather events will become the new normal. A once-in-50-year storm could become once a decade, or once a year, for example.

In 2013, the Ayalon – the highway cutting through Tel Aviv – turned into a river because of a “once-in-100-year storm.” It happened again the next year, and again in 2018. It must also be pointed out that it happened beforehand too, just rather less dramatically. In 2013, some people even challenged the fates by kayaking down the flooded road, or floating in tire tubes. Police even had to rescue one guy whose kayak overturned.

As the Swedish scientists helpfully elucidated, global warming will change the predictability of the chaotic atmosphere – and not for the better. While the margin of error in large-scale forecasting may improve thanks to our improving technology, the margin of error in local weather forecasting will widen because of the mounting uncertainties combined with the sheer number of parameters that can have influence.

As they mop out their flooded ground-floor apartments, Israelis can feel the uncertainty personally. Stormy weather had been forecast for this last weekend, but that’s been the case several times in recent weeks, and clouds did ensue then but that was about it.

Shahar L., a motorcycle courier who delivers mainly restaurant meals, doesn’t routinely check forecasts – partly because he doesn’t trust them, and partly because he has to work in sun and rain anyway, he tells Haaretz. If he could, he would book to work more rainy days, despite the hazard of slippery tarmac. “Usually, during rainy weather people order more – but they tip more,” he explains. Score one for Israeli empathy.

But this Shabbat, as rain fell in buckets and roads turned into rivulets, orders atypically fell off. Compassion for moped couriers in this extreme weather evidently prevailed over their passion for pizza.

Can Tel Aviv do anything realistic to stave off more sudden flooding? Might the large-scale rain-drains Singapore built by the roads be the ticket for it? For one thing Israel’s crowded cities typically don’t have the room to just dig giant new drains by the road. For another, the need for them still isn’t clear: this region is drying out, not becoming generally waterlogged. Singapore meanwhile may find that even its system, built decades ago, won’t cut it in the era of climate change.