Can we switch off El Nino? Scientists say thousands of salt-spraying ships might
Scientists say 2,000 ships spraying seawater over the Pacific could weaken a super El Nino before it peaks. Here is what the new study means for India's monsoon, and why researchers remain uneasy.
Off the coast of Peru, over a patch of ocean roughly the size of India, sits one of the most boring skies on Earth. A low sheet of grey cloud over cold water. It does not really rain. It does not really break.
Climate scientists now believe this dull sky may be the most powerful lever humanity has ever found over extreme weather.
Their proposal is startling in its simplicity. Send about 2,000 ships there. Spray a fine mist of seawater upwards for nine months. Make those clouds slightly whiter.
And a super El Nino, forming 8,000 kilometres away, quietly fails to happen.
First, the basics. El Nino is a natural warming of the Pacific Ocean that returns every few years and reshuffles weather across the planet. A strong one is often called a super or Godzilla El Nino.
If you live in India, it concerns you more than almost anyone, because when El Nino is strong, our monsoon tends to be weak. And a very strong El Nino is forming right now.
WHAT IS BEING PROPOSED?
The study, "Targeted marine cloud brightening weakens subsequent El Nino", appeared in the journal Science Advances on July 8. A free earlier version sits on arXiv, a website where scientists post their work before it is formally published.
It was led by Jessica S. Wan, who began the work at the Scripps Institution of Oceanography in California and is now at the University of Chicago, with Katharine Ricke of Scripps and the University of California San Diego.
The technique belongs to a controversial idea called solar geoengineering. That simply means deliberately bouncing a little more sunlight back into space to cool things down.
But this paper does something no such study has done before. It does not try to cool the whole planet, and it does not run for decades. It switches on in June and off in February.
HOW DO YOU BRIGHTEN A CLOUD?
You do not add chemicals. You add salt.
Ships spray tiny droplets of seawater upwards. The water dries out in the air, leaving behind minute grains of sea salt that float up into the cloud above.
Here is the key bit. A cloud is made of water droplets, and each droplet can only form if it has a speck of something to gather around.
Add more specks, and the same amount of water gets split into many more, much smaller droplets.
A cloud made of countless tiny droplets is whiter than a cloud made of fewer big ones, the same way crushed ice looks whiter than a single ice cube.
A whiter cloud reflects more sunlight, so the sea beneath it cools.
This is not exotic physics. Those bright white lines you sometimes see crossing the ocean in satellite photographs are trails left by ships, clouds accidentally brightened by the soot from their engines.
Ships have been doing this by mistake for a hundred years.
WHY PERU, TO FIX A PROBLEM NEAR INDONESIA?
El Nino lives in the middle of the Pacific. Yet the scientists chose to brighten clouds thousands of kilometres away, off Peru and Chile. To see why, you have to understand what El Nino actually is.
It is not simply a warm patch of water. It is a loop that feeds itself.
Normally, steady winds blow across the Pacific from east to west, pushing warm surface water towards Asia. If those winds weaken even slightly, the warm water slides back eastwards. That warmer water in the east weakens the winds a little more. Weaker winds let still more warm water slide east. Round and round it goes, each turn making the next one stronger.
Scientists have a name for this self-feeding loop: the Bjerknes feedback, after the researcher who first described it. Once it is spinning properly, almost nothing stops it.
Cooling that patch of sea off South America raises the air pressure sitting on top of it. Think of cool air as heavier, pressing down harder. That extra push strengthens the Pacific winds again, and stronger winds pull cold water up from the deep ocean.
The trade winds over the Pacific blow from east to west in normal conditions, that is, from the South American or eastern side (Peru, Chile) towards the Asian or western side (Indonesia, Australia). So Peru sits at the eastern end of the Pacific, where the winds begin their journey, and the warm water gets pushed away from Peru towards the western Pacific, where Asia lies.
During El Nino, this breaks down. The trade winds slacken. Without them pushing steadily westwards, the warm water that normally piles up near Asia slides back east towards Peru, and the cold water that usually rises along the South American coast stops surfacing. The eastern Pacific, off Peru, turns unusually warm, and that warmth weakens the winds further, which lets even more warm water drift east. The loop feeds itself.
So the plan is not to fight the heat directly. It is to jam the loop before it can build.
THE ACCIDENT THAT STARTED IT
Nobody would ever be allowed to test something like this on purpose. Nature tested it instead.
During Australia's Black Summer bushfires of 2019 and 2020, huge amounts of smoke drifted east across the South Pacific, passing directly over that same dull patch of cloud. The smoke particles did exactly what the sea salt would do.
The clouds brightened. The ocean beneath cooled. And an unusually long La Nina, the cool opposite of El Nino, followed and lasted three years.
Earlier research by John Fasullo, a co-author of the new study, argued that the fires helped cause it. A planet-sized experiment had already been run by accident, and somebody had been taking notes.
WHAT THE MODEL SHOWED
The team could not experiment on the real ocean, so they used a climate model instead: a giant computer simulation of the Earth's oceans and atmosphere.
They rebuilt two of the strongest El Ninos in living memory, from 1997 and 2015, inside the model, then ran them again with the imaginary ships switched on.
Spraying from June right through to the following February cut the peak warming of the 2015 event by roughly 1.5 degrees Celsius. That was enough to stop one of the century’s strongest El Ninos counting as an El Nino at all.
Spraying only from June to August cut it by 0.83 degrees. Spraying only in December, at the peak, cut it by a mere 0.31 degrees. Barely a scratch.
And here is the finding that makes this science serious. December is high summer in the southern half of the world, so the Sun is strong and that late spraying actually blocked a decent amount of sunlight. Yet it achieved almost nothing.
That mismatch is the whole discovery. The cooling is not doing the work directly. Early spraying worked because it strengthened the winds and restored the natural temperature gap between the eastern and western Pacific.
It ran the self-feeding loop backwards. The December spraying just chilled some water near Chile and left the loop spinning.
It is the difference between stopping a boulder at the top of a hill and trying to stop it halfway down.
WHAT IT WOULD MEAN FOR INDIA
Around half of India’s farmland has no irrigation at all. It waits for the monsoon. Ask any farm economist about 1997, 2009 and 2015, all difficult years.
The study looked at 14 regions around the world where El Nino reliably changes the weather. South Asia, where El Nino tends to bring extra heat, was one of them, and the longest spraying strategy reduced that heat. La Nina years are usually kind to our monsoon, so weakening an El Nino could be doubly good news here.
That is exactly what worries other countries. The same shift that fills Indian reservoirs could arrive in Australia as floods. The cycle does not vanish. It just moves.
And remember where the ships would sit. Off Peru, half a world away from every farmer whose harvest depends on the result. No treaty exists anywhere that would require whoever does this to ask India first.
WHY SCIENTISTS ARE UNEASY
The machines do not exist. David Keith of the University of Chicago points out that the sprayers built so far are, in his words, at least a hundred times too weak to be of practical use.
A different climate model disagrees violently. James Haywood of the University of Exeter, running similar tests on another model, found that cooling the eastern Pacific this way could instead trigger a mega La Nina, stronger than anything ever recorded.
And most of the benefits are unproven. Each scenario was run only 10 times, and of those 14 regional effects, just two were statistically solid, meaning the rest could still be down to ordinary chance.
There is an irony too. Wan’s own 2024 study in Nature Climate Change found that this kind of cloud brightening works less well as the planet heats up. The tool may fade just as the problem grows.
COULD WE STOP THIS ONE?
No, and the researchers say so plainly. America's weather agency, NOAA, declared El Nino conditions in June. By mid-July, 23 of 26 international forecasting models were pointing to a very strong event peaking between October and January.
There are no sprayers, no fleet, no law and no organisation with the authority to decide. There is also a stubborn scientific limit called the spring predictability barrier.
You would be sending out thousands of ships on a forecast that had only just become trustworthy.
For 30 years, the argument over solar geoengineering has been about whether we should permanently dim the Sun to cancel out the warming from carbon dioxide. This paper asks something smaller and stranger.
Could you step in for nine months, against a natural cycle rather than against pollution, and then simply stop?
Daniele Visioni of Cornell University, who was not involved, called the work "in no way the final answer", but thinks the question is worth asking, given what large El Ninos cost. Research published in Science puts that cost in the trillions of dollars.
To summarise, scientists have found, in computer simulations, that spraying seawater from about 2,000 ships to brighten clouds over the Pacific off Peru could weaken a super El Nino before it peaks.
Brighter clouds reflect more sunlight, cooling the ocean and jamming the self-feeding loop that powers El Nino.
The idea matters to India because strong El Ninos usually mean weak monsoons. But the technology does not yet exist. One rival model warns of a dangerous overcorrection, and no law governs who could decide to try it.
Not a plan, then, or a proposal. A question that has become much harder to dismiss.
And a monsoon, arriving next June, that will succeed or fail entirely on its own.
Off the coast of Peru, over a patch of ocean roughly the size of India, sits one of the most boring skies on Earth. A low sheet of grey cloud over cold water. It does not really rain. It does not really break.
Climate scientists now believe this dull sky may be the most powerful lever humanity has ever found over extreme weather.
Their proposal is startling in its simplicity. Send about 2,000 ships there. Spray a fine mist of seawater upwards for nine months. Make those clouds slightly whiter.
And a super El Nino, forming 8,000 kilometres away, quietly fails to happen.
First, the basics. El Nino is a natural warming of the Pacific Ocean that returns every few years and reshuffles weather across the planet. A strong one is often called a super or Godzilla El Nino.
If you live in India, it concerns you more than almost anyone, because when El Nino is strong, our monsoon tends to be weak. And a very strong El Nino is forming right now.
WHAT IS BEING PROPOSED?
The study, "Targeted marine cloud brightening weakens subsequent El Nino", appeared in the journal Science Advances on July 8. A free earlier version sits on arXiv, a website where scientists post their work before it is formally published.
It was led by Jessica S. Wan, who began the work at the Scripps Institution of Oceanography in California and is now at the University of Chicago, with Katharine Ricke of Scripps and the University of California San Diego.
The technique belongs to a controversial idea called solar geoengineering. That simply means deliberately bouncing a little more sunlight back into space to cool things down.
But this paper does something no such study has done before. It does not try to cool the whole planet, and it does not run for decades. It switches on in June and off in February.
HOW DO YOU BRIGHTEN A CLOUD?
You do not add chemicals. You add salt.
Ships spray tiny droplets of seawater upwards. The water dries out in the air, leaving behind minute grains of sea salt that float up into the cloud above.
Here is the key bit. A cloud is made of water droplets, and each droplet can only form if it has a speck of something to gather around.
Add more specks, and the same amount of water gets split into many more, much smaller droplets.
A cloud made of countless tiny droplets is whiter than a cloud made of fewer big ones, the same way crushed ice looks whiter than a single ice cube.
A whiter cloud reflects more sunlight, so the sea beneath it cools.
This is not exotic physics. Those bright white lines you sometimes see crossing the ocean in satellite photographs are trails left by ships, clouds accidentally brightened by the soot from their engines.
Ships have been doing this by mistake for a hundred years.
WHY PERU, TO FIX A PROBLEM NEAR INDONESIA?
El Nino lives in the middle of the Pacific. Yet the scientists chose to brighten clouds thousands of kilometres away, off Peru and Chile. To see why, you have to understand what El Nino actually is.
It is not simply a warm patch of water. It is a loop that feeds itself.
Normally, steady winds blow across the Pacific from east to west, pushing warm surface water towards Asia. If those winds weaken even slightly, the warm water slides back eastwards. That warmer water in the east weakens the winds a little more. Weaker winds let still more warm water slide east. Round and round it goes, each turn making the next one stronger.
Scientists have a name for this self-feeding loop: the Bjerknes feedback, after the researcher who first described it. Once it is spinning properly, almost nothing stops it.
Cooling that patch of sea off South America raises the air pressure sitting on top of it. Think of cool air as heavier, pressing down harder. That extra push strengthens the Pacific winds again, and stronger winds pull cold water up from the deep ocean.
The trade winds over the Pacific blow from east to west in normal conditions, that is, from the South American or eastern side (Peru, Chile) towards the Asian or western side (Indonesia, Australia). So Peru sits at the eastern end of the Pacific, where the winds begin their journey, and the warm water gets pushed away from Peru towards the western Pacific, where Asia lies.
During El Nino, this breaks down. The trade winds slacken. Without them pushing steadily westwards, the warm water that normally piles up near Asia slides back east towards Peru, and the cold water that usually rises along the South American coast stops surfacing. The eastern Pacific, off Peru, turns unusually warm, and that warmth weakens the winds further, which lets even more warm water drift east. The loop feeds itself.
So the plan is not to fight the heat directly. It is to jam the loop before it can build.
THE ACCIDENT THAT STARTED IT
Nobody would ever be allowed to test something like this on purpose. Nature tested it instead.
During Australia's Black Summer bushfires of 2019 and 2020, huge amounts of smoke drifted east across the South Pacific, passing directly over that same dull patch of cloud. The smoke particles did exactly what the sea salt would do.
The clouds brightened. The ocean beneath cooled. And an unusually long La Nina, the cool opposite of El Nino, followed and lasted three years.
Earlier research by John Fasullo, a co-author of the new study, argued that the fires helped cause it. A planet-sized experiment had already been run by accident, and somebody had been taking notes.
WHAT THE MODEL SHOWED
The team could not experiment on the real ocean, so they used a climate model instead: a giant computer simulation of the Earth's oceans and atmosphere.
They rebuilt two of the strongest El Ninos in living memory, from 1997 and 2015, inside the model, then ran them again with the imaginary ships switched on.
Spraying from June right through to the following February cut the peak warming of the 2015 event by roughly 1.5 degrees Celsius. That was enough to stop one of the century’s strongest El Ninos counting as an El Nino at all.
Spraying only from June to August cut it by 0.83 degrees. Spraying only in December, at the peak, cut it by a mere 0.31 degrees. Barely a scratch.
And here is the finding that makes this science serious. December is high summer in the southern half of the world, so the Sun is strong and that late spraying actually blocked a decent amount of sunlight. Yet it achieved almost nothing.
That mismatch is the whole discovery. The cooling is not doing the work directly. Early spraying worked because it strengthened the winds and restored the natural temperature gap between the eastern and western Pacific.
It ran the self-feeding loop backwards. The December spraying just chilled some water near Chile and left the loop spinning.
It is the difference between stopping a boulder at the top of a hill and trying to stop it halfway down.
WHAT IT WOULD MEAN FOR INDIA
Around half of India’s farmland has no irrigation at all. It waits for the monsoon. Ask any farm economist about 1997, 2009 and 2015, all difficult years.
The study looked at 14 regions around the world where El Nino reliably changes the weather. South Asia, where El Nino tends to bring extra heat, was one of them, and the longest spraying strategy reduced that heat. La Nina years are usually kind to our monsoon, so weakening an El Nino could be doubly good news here.
That is exactly what worries other countries. The same shift that fills Indian reservoirs could arrive in Australia as floods. The cycle does not vanish. It just moves.
And remember where the ships would sit. Off Peru, half a world away from every farmer whose harvest depends on the result. No treaty exists anywhere that would require whoever does this to ask India first.
WHY SCIENTISTS ARE UNEASY
The machines do not exist. David Keith of the University of Chicago points out that the sprayers built so far are, in his words, at least a hundred times too weak to be of practical use.
A different climate model disagrees violently. James Haywood of the University of Exeter, running similar tests on another model, found that cooling the eastern Pacific this way could instead trigger a mega La Nina, stronger than anything ever recorded.
And most of the benefits are unproven. Each scenario was run only 10 times, and of those 14 regional effects, just two were statistically solid, meaning the rest could still be down to ordinary chance.
There is an irony too. Wan’s own 2024 study in Nature Climate Change found that this kind of cloud brightening works less well as the planet heats up. The tool may fade just as the problem grows.
COULD WE STOP THIS ONE?
No, and the researchers say so plainly. America's weather agency, NOAA, declared El Nino conditions in June. By mid-July, 23 of 26 international forecasting models were pointing to a very strong event peaking between October and January.
There are no sprayers, no fleet, no law and no organisation with the authority to decide. There is also a stubborn scientific limit called the spring predictability barrier.
You would be sending out thousands of ships on a forecast that had only just become trustworthy.
For 30 years, the argument over solar geoengineering has been about whether we should permanently dim the Sun to cancel out the warming from carbon dioxide. This paper asks something smaller and stranger.
Could you step in for nine months, against a natural cycle rather than against pollution, and then simply stop?
Daniele Visioni of Cornell University, who was not involved, called the work "in no way the final answer", but thinks the question is worth asking, given what large El Ninos cost. Research published in Science puts that cost in the trillions of dollars.
To summarise, scientists have found, in computer simulations, that spraying seawater from about 2,000 ships to brighten clouds over the Pacific off Peru could weaken a super El Nino before it peaks.
Brighter clouds reflect more sunlight, cooling the ocean and jamming the self-feeding loop that powers El Nino.
The idea matters to India because strong El Ninos usually mean weak monsoons. But the technology does not yet exist. One rival model warns of a dangerous overcorrection, and no law governs who could decide to try it.
Not a plan, then, or a proposal. A question that has become much harder to dismiss.
And a monsoon, arriving next June, that will succeed or fail entirely on its own.
Off the coast of Peru, over a patch of ocean roughly the size of India, sits one of the most boring skies on Earth. A low sheet of grey cloud over cold water. It does not really rain. It does not really break.
Climate scientists now believe this dull sky may be the most powerful lever humanity has ever found over extreme weather.
Their proposal is startling in its simplicity. Send about 2,000 ships there. Spray a fine mist of seawater upwards for nine months. Make those clouds slightly whiter.
And a super El Nino, forming 8,000 kilometres away, quietly fails to happen.
First, the basics. El Nino is a natural warming of the Pacific Ocean that returns every few years and reshuffles weather across the planet. A strong one is often called a super or Godzilla El Nino.
If you live in India, it concerns you more than almost anyone, because when El Nino is strong, our monsoon tends to be weak. And a very strong El Nino is forming right now.
WHAT IS BEING PROPOSED?
The study, "Targeted marine cloud brightening weakens subsequent El Nino", appeared in the journal Science Advances on July 8. A free earlier version sits on arXiv, a website where scientists post their work before it is formally published.
It was led by Jessica S. Wan, who began the work at the Scripps Institution of Oceanography in California and is now at the University of Chicago, with Katharine Ricke of Scripps and the University of California San Diego.
The technique belongs to a controversial idea called solar geoengineering. That simply means deliberately bouncing a little more sunlight back into space to cool things down.
But this paper does something no such study has done before. It does not try to cool the whole planet, and it does not run for decades. It switches on in June and off in February.
HOW DO YOU BRIGHTEN A CLOUD?
You do not add chemicals. You add salt.
Ships spray tiny droplets of seawater upwards. The water dries out in the air, leaving behind minute grains of sea salt that float up into the cloud above.
Here is the key bit. A cloud is made of water droplets, and each droplet can only form if it has a speck of something to gather around.
Add more specks, and the same amount of water gets split into many more, much smaller droplets.
A cloud made of countless tiny droplets is whiter than a cloud made of fewer big ones, the same way crushed ice looks whiter than a single ice cube.
A whiter cloud reflects more sunlight, so the sea beneath it cools.
This is not exotic physics. Those bright white lines you sometimes see crossing the ocean in satellite photographs are trails left by ships, clouds accidentally brightened by the soot from their engines.
Ships have been doing this by mistake for a hundred years.
WHY PERU, TO FIX A PROBLEM NEAR INDONESIA?
El Nino lives in the middle of the Pacific. Yet the scientists chose to brighten clouds thousands of kilometres away, off Peru and Chile. To see why, you have to understand what El Nino actually is.
It is not simply a warm patch of water. It is a loop that feeds itself.
Normally, steady winds blow across the Pacific from east to west, pushing warm surface water towards Asia. If those winds weaken even slightly, the warm water slides back eastwards. That warmer water in the east weakens the winds a little more. Weaker winds let still more warm water slide east. Round and round it goes, each turn making the next one stronger.
Scientists have a name for this self-feeding loop: the Bjerknes feedback, after the researcher who first described it. Once it is spinning properly, almost nothing stops it.
Cooling that patch of sea off South America raises the air pressure sitting on top of it. Think of cool air as heavier, pressing down harder. That extra push strengthens the Pacific winds again, and stronger winds pull cold water up from the deep ocean.
The trade winds over the Pacific blow from east to west in normal conditions, that is, from the South American or eastern side (Peru, Chile) towards the Asian or western side (Indonesia, Australia). So Peru sits at the eastern end of the Pacific, where the winds begin their journey, and the warm water gets pushed away from Peru towards the western Pacific, where Asia lies.
During El Nino, this breaks down. The trade winds slacken. Without them pushing steadily westwards, the warm water that normally piles up near Asia slides back east towards Peru, and the cold water that usually rises along the South American coast stops surfacing. The eastern Pacific, off Peru, turns unusually warm, and that warmth weakens the winds further, which lets even more warm water drift east. The loop feeds itself.
So the plan is not to fight the heat directly. It is to jam the loop before it can build.
THE ACCIDENT THAT STARTED IT
Nobody would ever be allowed to test something like this on purpose. Nature tested it instead.
During Australia's Black Summer bushfires of 2019 and 2020, huge amounts of smoke drifted east across the South Pacific, passing directly over that same dull patch of cloud. The smoke particles did exactly what the sea salt would do.
The clouds brightened. The ocean beneath cooled. And an unusually long La Nina, the cool opposite of El Nino, followed and lasted three years.
Earlier research by John Fasullo, a co-author of the new study, argued that the fires helped cause it. A planet-sized experiment had already been run by accident, and somebody had been taking notes.
WHAT THE MODEL SHOWED
The team could not experiment on the real ocean, so they used a climate model instead: a giant computer simulation of the Earth's oceans and atmosphere.
They rebuilt two of the strongest El Ninos in living memory, from 1997 and 2015, inside the model, then ran them again with the imaginary ships switched on.
Spraying from June right through to the following February cut the peak warming of the 2015 event by roughly 1.5 degrees Celsius. That was enough to stop one of the century’s strongest El Ninos counting as an El Nino at all.
Spraying only from June to August cut it by 0.83 degrees. Spraying only in December, at the peak, cut it by a mere 0.31 degrees. Barely a scratch.
And here is the finding that makes this science serious. December is high summer in the southern half of the world, so the Sun is strong and that late spraying actually blocked a decent amount of sunlight. Yet it achieved almost nothing.
That mismatch is the whole discovery. The cooling is not doing the work directly. Early spraying worked because it strengthened the winds and restored the natural temperature gap between the eastern and western Pacific.
It ran the self-feeding loop backwards. The December spraying just chilled some water near Chile and left the loop spinning.
It is the difference between stopping a boulder at the top of a hill and trying to stop it halfway down.
WHAT IT WOULD MEAN FOR INDIA
Around half of India’s farmland has no irrigation at all. It waits for the monsoon. Ask any farm economist about 1997, 2009 and 2015, all difficult years.
The study looked at 14 regions around the world where El Nino reliably changes the weather. South Asia, where El Nino tends to bring extra heat, was one of them, and the longest spraying strategy reduced that heat. La Nina years are usually kind to our monsoon, so weakening an El Nino could be doubly good news here.
That is exactly what worries other countries. The same shift that fills Indian reservoirs could arrive in Australia as floods. The cycle does not vanish. It just moves.
And remember where the ships would sit. Off Peru, half a world away from every farmer whose harvest depends on the result. No treaty exists anywhere that would require whoever does this to ask India first.
WHY SCIENTISTS ARE UNEASY
The machines do not exist. David Keith of the University of Chicago points out that the sprayers built so far are, in his words, at least a hundred times too weak to be of practical use.
A different climate model disagrees violently. James Haywood of the University of Exeter, running similar tests on another model, found that cooling the eastern Pacific this way could instead trigger a mega La Nina, stronger than anything ever recorded.
And most of the benefits are unproven. Each scenario was run only 10 times, and of those 14 regional effects, just two were statistically solid, meaning the rest could still be down to ordinary chance.
There is an irony too. Wan’s own 2024 study in Nature Climate Change found that this kind of cloud brightening works less well as the planet heats up. The tool may fade just as the problem grows.
COULD WE STOP THIS ONE?
No, and the researchers say so plainly. America's weather agency, NOAA, declared El Nino conditions in June. By mid-July, 23 of 26 international forecasting models were pointing to a very strong event peaking between October and January.
There are no sprayers, no fleet, no law and no organisation with the authority to decide. There is also a stubborn scientific limit called the spring predictability barrier.
You would be sending out thousands of ships on a forecast that had only just become trustworthy.
For 30 years, the argument over solar geoengineering has been about whether we should permanently dim the Sun to cancel out the warming from carbon dioxide. This paper asks something smaller and stranger.
Could you step in for nine months, against a natural cycle rather than against pollution, and then simply stop?
Daniele Visioni of Cornell University, who was not involved, called the work "in no way the final answer", but thinks the question is worth asking, given what large El Ninos cost. Research published in Science puts that cost in the trillions of dollars.
To summarise, scientists have found, in computer simulations, that spraying seawater from about 2,000 ships to brighten clouds over the Pacific off Peru could weaken a super El Nino before it peaks.
Brighter clouds reflect more sunlight, cooling the ocean and jamming the self-feeding loop that powers El Nino.
The idea matters to India because strong El Ninos usually mean weak monsoons. But the technology does not yet exist. One rival model warns of a dangerous overcorrection, and no law governs who could decide to try it.
Not a plan, then, or a proposal. A question that has become much harder to dismiss.
And a monsoon, arriving next June, that will succeed or fail entirely on its own.
