The Atlantic’s Warning, the Levant’s Reality

British scientists have just detected something from space that should be read carefully in Jerusalem, though it concerns a sea more than two thousand miles away. Researchers at Plymouth Marine Laboratory, working through two decades of satellite data from 1997 to 2018, have found that the waters around the United Kingdom and across much of the north east Atlantic are photosynthesising less than they used to. The microscopic plants that form the base of all marine life, and that quietly absorb a large share of the carbon dioxide humanity emits, are in measurable decline.

The cause is not pollution or overfishing, though both play their part elsewhere. It is heat. As the surface of the sea warms, it separates into more stable layers, a process called stratification. Those layers resist mixing, and mixing is what carries nutrients up from the cold depths to the sunlit surface where phytoplankton grow. Warm the top, and you starve the engine. The Plymouth team, led by Dr Gavin Tilstone and Dr Peter Land and published this month in Frontiers in Remote Sensing, traced the decline precisely to rising sea surface temperature and the deepening calm that follows it.

For Britain this is a warning about the future. For Israel it is a description of the present. The reason the finding matters to Israel is that the Eastern Mediterranean has already travelled the road the Atlantic has only just started down.

The Levantine basin, the body of water lapping Israel’s coast, is among the warmest, saltiest and least productive seas on earth. Its surface has warmed by roughly three degrees in recent decades, faster than almost any comparable sea, and it is so nutrient poor that its primary production runs at around half that of the Atlantic’s famously barren Sargasso Sea. Some of that barrenness is structural and predates the warming, a product of the basin’s peculiar circulation and the loss of Nile nutrients after the Aswan Dam. But the mechanism the Plymouth team identified, warming that drives stratification and starves the surface of nutrients, is the same one now deepening the Levant’s poverty, which is why marine scientists treat this sea not as a backwater but as a natural laboratory for what falling productivity looks like once it has fully set in. What the British satellites have glimpsed faintly in cool northern water, Israelis live with as an established condition.

This is not an abstract concern, and three consequences are already visible. The first is fish. A study published this year on the impact of a warming sea on Israel’s fishing economy describes native temperate species retreating while heat loving and invasive species, many of them arrivals through the Suez Canal, move in to replace them. Catch composition is already shifting, biomass is projected to fall, and the variability that makes a fishery hard to manage is rising. The second is the food web itself, because every fish on a Haifa quayside ultimately depends on the sunlight that phytoplankton fix, and a thinning base means a thinning everything above it.

The third consequence is the one that should command a cabinet’s attention, though for a reason more specific than the headlines suggest. Israel drinks its sea. Between seventy and eighty percent of the country’s drinking water now comes from desalination plants strung along the Mediterranean coast, a remarkable achievement that has freed Israel from the tyranny of drought and a dwindling Sea of Galilee. Falling phytoplankton productivity does not threaten that supply directly, because a reverse osmosis plant needs seawater, not plankton, and warming does not take the seawater away. The threat is more particular. A hotter Eastern Mediterranean is a more hospitable one for the nomad jellyfish, an invasive species that arrived through the Suez Canal and now swarms each summer when the water reaches the high twenties. Those swarms clog the seawater intakes that feed both the coastal power stations and the desalination plants, and the State Comptroller has estimated the potential multi year cost to desalination alone in the tens of millions of shekels. The point is not that the sea will stop giving water, but that the same warming which is thinning the food web is also fouling the machinery on which the nation’s tap now depends. A sea under stress is no longer an environmental file. It is national infrastructure, as strategic as the electricity grid or the gas fields, and far less discussed.

Israel is unusually well placed to lead here rather than merely worry. Off the coast of Haifa, at fifteen hundred metres depth, sits one of the few deep sea monitoring stations in the entire Eastern Mediterranean, gathering exactly the kind of long record that allowed the British to spot their trend. Israeli oceanography is strong, its technology sector is hungry for hard environmental problems, and the country already exports its water expertise to dozens of nations. The instinct to treat the sea as scenery rather than as a system is the one thing standing in the way.

There is a diplomatic dividend too. The Levantine basin is shared with Cyprus, Greece, Egypt, Lebanon and others, and water does not recognise borders or grievances. The science of a warming sea is one of the few subjects on which states that agree on almost nothing can still find reason to cooperate, because the heat rising through the water column is indifferent to whose coast it warms. A regional effort to monitor and understand the Eastern Mediterranean would serve Israel’s interests and, quietly, its standing.

The Mediterranean has shaped the Jewish story for three thousand years, as a route, a frontier and a livelihood. Now its very chemistry is changing, and a laboratory in the south west of England has handed Israel an unintended gift: confirmation, written in light gathered from orbit, of a process its own waters have been running for years. Britain reads the Atlantic carefully. Israel should read the Levant at least as well, because it is not waiting for the future. It is already in it.