Earth’s Cloud Calamity Explained

Part One of Three: Ocean Pastures, Clouds, and Climate

© Russ George

Climate Boffins Finally Noticed Something Had Broken in 2023

In the summer of 2023, every temperature record on Earth shattered. Not by the thin margins climate scientists had been tracking for decades, but by a full quarter of a degree Celsius beyond what anyone predicted. Global average temperatures didn’t just nudge past previous records—they leapt past them. The North Atlantic hit temperatures that existing models said shouldn’t arrive until the 2060s. Antarctic sea ice didn’t just retreat; it fell off a cliff, recording the lowest extent since satellite monitoring began.

Scientists were stunned. Not alarmed in the usual, carefully-hedged way of peer-reviewed understatement/bafle-gab. Stunned. The world’s best climate models—the ones that have reliably tracked warming for fifty years—suddenly couldn’t account for what the thermometers were showing.

Something extra was heating the planet. Something the models hadn’t captured. The question that kept every serious climate researcher awake in late 2023 and into 2024 was simple, and terrifying: Where was the extra heat coming from?

The Missing 0.2°C

Here’s what made it truly puzzling. We know how much greenhouse gas humanity has pumped into the atmosphere. We can measure it precisely—CO₂, methane, nitrous oxide, the works. We know the radiative forcing those gases produce. The models account for all of it. They also account for volcanic eruptions, solar cycles, El Niño events, and aerosol pollution from industrial activity.

And yet, when you ran the numbers for 2023, reality exceeded the models by roughly 0.2°C. That might sound like a rounding error to a layperson. It’s not. In a system as massive as Earth’s climate, 0.2°C of unexplained warming is an enormous anomaly. It represents a colossal amount of additional energy being absorbed by the planet—energy that had to be coming from somewhere.

How unlikely is that surplus? Once you account for everything the models do capture—greenhouse gases, El Niño, volcanic aerosols, solar cycles—the residual variability in global temperature has a standard deviation of roughly 0.06–0.08°C. Against that baseline, 0.2°C of unexplained warming is a 3-sigma event—a departure so far outside natural variability that it occurs by chance perhaps once in a thousand years. This wasn’t noise. This was a signal screaming for attribution.

The scientific community spent more than a year chasing this mystery. In early 2025, the answer arrived. And it wasn’t what most people expected.

It’s the Clouds

In January 2025, Goessling and colleagues published a landmark paper in Science with a finding that should have made front-page news everywhere. They showed that Earth’s planetary albedo—the fraction of sunlight our planet reflects back into space—had fallen to its lowest level since 1940. Their analysis was meticulous: without the reduced albedo observed since December 2020, global temperatures in 2023 would have been 0.23°C cooler.

There it was. The missing heat. Not from extra greenhouse gases. Not from a rogue El Niño. The planet was absorbing more sunlight because it was reflecting less of it.

“The recent collapse in marine cloud reflectivity represents an added radiative forcing of roughly 1–1.5 W/m², making it energetically comparable to one-third to one-half of all historical CO₂ forcing, compressed into a single decade.”

But here’s the finding that should stop you in your tracks: of that albedo decline, 85% came from the loss of clouds. Only 15% came from the loss of polar ice and snow.

Think about that for a moment. The entire public and political conversation about reflectivity has been dominated by melting ice caps. White ice disappearing, dark ocean absorbing more heat—it’s the canonical image of climate feedback. And yet the actual data show that lost clouds are contributing nearly six times more to Earth’s energy imbalance than lost ice.

We’ve been watching the ice while the clouds vanished above our heads.

The Staggering Numbers

If the Goessling paper was the detective identifying the suspect, the Tselioudis paper in Geophysical Research Letters was the forensic report. Published the same month, it revealed that Earth’s storm-cloud zones have been contracting by 1.5 to 3% per decade for the past 24 years. The areas of strongest cloud radiative cooling—those vast, bright regions of marine stratus and stratocumulus that reflect enormous amounts of sunlight—are shrinking at a rate of 0.88 to 1.32% per decade.

This contraction is adding 0.37 watts per square meter per decade of additional heating to the planet’s energy budget. That’s a relentless, compounding increase in absorbed solar energy that has been going on, largely unnoticed, for a quarter century.

Then came James Hansen—NASA’s legendary climate scientist, the man who first warned Congress about global warming in 1988. In his 2025 analysis, Hansen calculated that Earth’s albedo declined by 0.5% between 2000 and 2024. The resulting additional absorbed energy? 1.7 watts per square meter.

Now compare that number to this one: the total radiative forcing from all greenhouse gas emissions over the entire 20th century is estimated at approximately 2.4 watts per square meter.

The cloud decline in just 24 years has added heating equivalent to more than 70% of what all human greenhouse gas emissions accomplished in a hundred years. Hansen, not known for hyperbole, called this finding a “BFD”—a Big F-ing Deal. He was being restrained.

Where the Clouds Are Disappearing

The cloud loss isn’t random. It follows a pattern that tells a story, if you know how to read it.

The most dramatic declines are concentrated over the Atlantic Ocean, the Northern Hemisphere mid-latitudes, and the tropics. These are precisely the regions where vast expanses of low marine clouds—stratocumulus and stratus decks—have historically acted as Earth’s great reflective shield. They’re also the regions where the ocean surface interfaces most powerfully with the atmosphere to drive cloud formation.

The North Atlantic has been hit particularly hard. This isn’t a coincidence. This is the same ocean basin where sea surface temperatures exploded past all historical records in 2023 and have remained stubbornly elevated. Less cloud cover means more sunlight hitting the water. More warm water means conditions that further suppress cloud formation. It’s a feedback loop, and it’s accelerating.

The tropical cloud zones, too, are contracting. Storm-track cloud systems are migrating poleward and weakening, opening wider and wider gaps in Earth’s reflective canopy. What were once reliably overcast ocean regions are becoming clearer, bluer, and hotter.

The Three Suspects

So what’s killing the clouds? The scientific literature has focused on three possible explanations.

Suspect 1: Clean Shipping Fuels

In 2020, the International Maritime Organization’s IMO 2020 regulation slashed the sulfur content of shipping fuel by over 80%. Ships had been spewing sulfur dioxide across every major shipping lane for decades, and those sulfur particles—as dirty as they were—served as cloud condensation nuclei. They seeded clouds. When we cleaned up the fuel (for excellent air-quality reasons), some researchers argue we inadvertently removed a source of cloud-forming particles over the oceans.

There’s something to this. But the timing is wrong for it to be the whole story. Cloud decline has been tracked since at least the year 2000—two full decades before IMO 2020 took effect. Shipping emissions may have contributed to the acceleration of cloud loss after 2020, but they can’t explain the long-term trend…. Bzzzt!

Suspect 2: Natural Variability and Cloud Feedback

Climate models predict that as the planet warms, certain cloud types—especially the low marine clouds that provide the strongest cooling—will diminish. This is what modelers call a “positive cloud feedback”: warming reduces clouds, which allows more warming, which reduces more clouds. Hansen’s 2025 paper identifies this feedback as a major driver, pushing effective climate sensitivity significantly higher than most models assumed…meh!

This is real and important. But it raises a deeper question: why are the clouds declining faster than models predicted? What mechanism is driving a cloud feedback that’s outpacing what greenhouse warming alone should produce?

Suspect 3: The One Nobody’s Investigating

And here we arrive at the question that should be on every climate scientist’s desk but somehow isn’t.

Why are the natural, biological sources of cloud-forming particles declining?

Because they are. Dramatically. And the evidence has been accumulating for years, largely ignored by the climate modeling community. Oh Shit !!!

The Question That Changes Everything

Clouds don’t just form from nothing. They require seeds—tiny particles called cloud condensation nuclei (CCN) around which water vapor can condense. And here’s a fact that deserves far more attention than it receives: more than three-quarters of all clouds on Earth exist over the oceans. Satellite data show that 72% of the ocean surface is cloud-covered at any given moment, compared to 55% over land. Since oceans cover 71% of the planet, the math is straightforward—76% of all cloud area is marine. Nearly 90% of all atmospheric moisture originates from ocean evaporation. On this blue planet, the sea doesn’t just host clouds. It manufactures them.

Over land, dust, soot, and industrial pollution provide cloud seeds in abundance. But over the vast open ocean—where three-quarters of the world’s clouds live—the primary source of CCN isn’t industrial. It’s biological.

The ocean’s great plankton pastures produce over one billion tonnes per year of a molecule called DMSP—dimethylsulphoniopropionate. When marine bacteria break down DMSP, they release dimethyl sulfide (DMS), that distinctive “smell of the sea.” DMS rises into the atmosphere, oxidizes into sulfate aerosol particles, and those particles become the seeds around which marine clouds form.

This isn’t a minor process. Research has shown that roughly 10% of all ocean photosynthesis is dedicated to producing these cloud-forming molecules. To put that in human terms: ocean photosynthesis captures approximately 62 terawatts of energy continuously. Ten percent of that is 6 terawatts—the equivalent of 6,000 large nuclear power plants running around the clock, year-round—devoted to a single task: manufacturing cloud seeds. Nature doesn’t make investments like that on a whim. This is planetary air conditioning, engineered by evolution over billions of years.

So here’s the question the 2025 papers don’t ask, but urgently need to:

What happens when the ocean pastures that produce those cloud seeds collapse?

Because they have collapsed. By 40 to 50% since the 1980s.

The decline in ocean phytoplankton productivity is one of the most alarming and least-discussed ecological catastrophes of our time. Satellite data, ship-based measurements, and proxy records all converge on the same devastating conclusion: the ocean’s great plankton pastures—I call them ocean pastures because that’s exactly what they are, the grasslands of the sea—have withered. Vast stretches of once-productive ocean have become what can only be called blue deserts.

Less plankton means less DMSP. Less DMSP means less DMS. Less DMS means fewer cloud condensation nuclei. Fewer nuclei means fewer clouds.

Fewer clouds means a hotter planet.

The timeline is not a coincidence. Ocean productivity began its steep decline in the 1980s. Cloud cover began its measurable decline around 2000, with acceleration after 2020. Albedo has fallen to its lowest point in at least 80 years, with 85% of that decline attributable to clouds.

The fingerprints match. The timeline matches. The geography matches—the same ocean regions losing plankton productivity are the same regions losing cloud cover.

Let’s Do Some Math

The energy budget reconciles with devastating precision. The ocean has lost roughly 3 terawatts of its cloud-seeding biological energy—the equivalent of shutting down thousands of nuclear power plants’ worth of nature’s air conditioning. Because cloud seeds are catalytic triggers, not the clouds themselves, that biological loss has unshielded the planet from approximately 740 terawatts of additional absorbed solar heating—an amplification ratio of roughly 250 to 1. That 740 terawatts, spread across Earth’s surface, equals the 1.45 W/m² cloud albedo signal that Goessling and Hansen measured. The math doesn’t just work. It snaps shut like a trap.

And yet, the three landmark 2025 papers that finally quantified the cloud crisis don’t explore this connection. Not because the evidence isn’t there, but because climate models have never been designed to see it. They treat oceans physically and chemically, but not biologically. The living ocean—the cloud-making, heat-reflecting, carbon-sequestering engine of ocean life—simply isn’t in the equations.

What Comes Next

The 2025 cloud papers represent a genuine breakthrough. For the first time, mainstream climate science has quantified the scale of the cloud crisis and acknowledged that lost reflectivity—not just greenhouse gases—is a primary driver of recent warming.

But they’ve identified the what without identifying the why. They’ve measured the fever without diagnosing the disease.

In the next article of this series, we’ll follow the evidence to its source. We’ll trace the chain from dying ocean pastures to disappearing clouds, and reveal why the collapse of the ocean’s biological systems isn’t just an environmental tragedy for fish and whales—it’s the missing piece of the climate puzzle that explains why our planet is heating faster than anyone predicted.

We’re not just losing fish. We’re losing our planet’s air conditioning system.

The oceans used to cool this blue planet with living systems—plankton pastures that shaded the seas, made clouds, and helped Earth breathe. Now those systems are collapsing, and Earth is running a fever not just because of our emissions—but because we’ve monkey-wrenched its air conditioner.

The good news? We know how to fix it. That story is coming.

Read the next installment https://russgeorge.net/2026/02/07/the-vital-ocean-connection/

References

Tselioudis, G., et al. (2025). “Contraction of the World’s Storm-Cloud Zones the Primary Contributor to the 21st Century Increase in the Earth’s Sunlight Absorption.” Geophysical Research Letters, 52, e2025GL114882.

Goessling, H. F., et al. (2024). “Recent global temperature surge intensified by record-low planetary albedo.” Science, 387(6729), 68–73.

Hansen, J., et al. (2025). “Large Cloud Feedback Confirms High Climate Sensitivity.” Preprint / working paper.

George, R. (2025). “Climate Science Has Ignored The Ocean Cooling Crisis.” russgeorge.net.

George, R. (2025). “Ocean Pasture Albedo Production: A Nature-Based Climate Solution Delivering Gigatonnes of CO₂e Mitigation Annually.” russgeorge.net.