by Daniel Brouse

Rerouting the Walker Circulation: The Pacific El Niño–Atlantic Niña Atmospheric Bridge

The unusual co-occurrence of a Pacific El Niño and an Atlantic Niña illustrates how strongly connected Earth’s climate system is. Although the Pacific and Atlantic are separate ocean basins, the atmosphere links them through planetary-scale circulation patterns.

One of the most important connections is the Walker circulation—a vast east-west circulation of rising and sinking air across the tropics. When El Niño warms the central and eastern tropical Pacific, it reorganizes convection, atmospheric pressure, and wind patterns across the tropics. Those changes can extend into the Atlantic, altering the trade winds and ocean circulation there.

The result is a remarkable sequence of interconnected processes: Pacific warming → atmospheric rerouting → Atlantic pressure changes → stronger trade winds → enhanced upwelling → Atlantic cooling.

1. Rerouting the Walker Circulation

Walker circulation / ENSO Teleconnection:
The Walker circulation is a large-scale tropical atmospheric circulation that links changes in convection, pressure, winds, and ocean–atmosphere heat exchange across the Pacific and beyond. During El Niño, changes in Pacific sea-surface temperatures reorganize this circulation, creating atmospheric teleconnections that can extend into the Atlantic.

Pacific warming:
During El Niño, unusually warm surface waters develop across the central and eastern tropical Pacific. The additional oceanic heat increases evaporation and fuels stronger deep atmospheric convection.

Shifted convection:
As warm, moisture-rich air rises over the anomalously warm Pacific, the center of tropical convection shifts eastward. This changes the pattern of rising and sinking air that defines the Walker circulation, redistributing atmospheric energy and altering pressure and wind patterns across the tropics.

Atlantic subsidence:
The reorganized tropical circulation can produce compensating regions of sinking, relatively dry air over parts of the tropical Atlantic and Caribbean. This subsidence suppresses cloud formation and deep convection and can contribute to higher surface pressure.

The atmospheric bridge:
The Pacific warming does not directly “cause” the Atlantic to cool. Instead, ENSO reorganizes the atmospheric circulation, and that planetary-scale response can alter Atlantic pressure, winds, evaporation, and ocean circulation—providing the atmospheric bridge between the two ocean basins.

2. The Planetary Teleconnection: From the Pacific to the Atlantic and Beyond

The ENSO teleconnection does not stop at the Atlantic. The atmospheric disturbance generated by El Niño can propagate across the tropics and into the extratropics, linking the Pacific to the Atlantic, North Atlantic, Europe, and the United Kingdom through a network of atmospheric circulation patterns.

As tropical convection shifts over the Pacific, it alters the distribution of atmospheric heating. These changes can generate large-scale Rossby waves that propagate through the atmosphere, modifying the position and strength of the jet streams, storm tracks, and persistent pressure systems far from the original Pacific anomaly.

Pacific → Atlantic

The first major connection is the tropical Atlantic.

Pacific El Niño
↓
Shifted tropical convection
↓
Walker circulation response
↓
Changes in tropical pressure and winds
↓
Atlantic trade-wind response
↓
Ocean circulation and sea-surface temperature changes

This atmospheric bridge helps explain how a warming anomaly in the Pacific can coincide with cooling in the tropical Atlantic.

Atlantic → North Atlantic → Europe

The teleconnection can extend farther north.

Changes in tropical heating and atmospheric wave patterns can influence the North Atlantic jet stream and pressure fields, including variations associated with the North Atlantic Oscillation (NAO). These changes can alter the path of Atlantic storms and the transport of heat and moisture toward Europe.

The United Kingdom sits downstream of this North Atlantic circulation and can therefore experience changes in the probability of particular weather regimes—even though the original oceanic disturbance began thousands of miles away in the tropical Pacific.

The relationship is probabilistic, not deterministic. ENSO is one influence among many, and the eventual European response depends on the season, the state of the North Atlantic, stratospheric conditions, and other interacting climate modes.

A Planetary Feedback Network

The important point is that this is not a simple one-way pipeline.

PACIFIC
🔥 El Niño
↓
ATMOSPHERE
Walker circulation + planetary waves
↓
ATLANTIC
Trade winds + ocean response
↓
NORTH ATLANTIC
Jet stream + NAO
↓
EUROPE / UK
Weather-pattern response
↓
GLOBAL OCEAN–ATMOSPHERE SYSTEM
↓
PACIFIC

The final connection back toward the Pacific should not be interpreted as a single atmospheric current literally traveling around the planet. Instead, it represents coupled feedbacks within the global climate system. Changes in one ocean basin alter atmospheric circulation; those atmospheric changes affect other ocean basins and land surfaces; and those changes can subsequently feed back into the global circulation system.

ENSO is therefore not simply a Pacific phenomenon.

It is a planetary-scale disturbance that can reorganize atmospheric and oceanic conditions across multiple basins and continents.

One ocean warms.
The atmosphere responds.
The response travels.
The planet adjusts.

3. Amplification of Atlantic Trade Winds

Pressure gradients:
The redistribution of rising and sinking air modifies sea-level pressure across the tropical Atlantic. A stronger pressure gradient can develop along the equatorial Atlantic.

Stronger easterly winds:
The resulting pressure gradient can strengthen the Atlantic trade winds. These persistent easterlies are critical because they directly interact with the ocean surface.

The atmosphere has effectively rerouted part of the Pacific’s excess energy through a planetary-scale circulation response, creating conditions that can cool a distant ocean basin.

4. Wind-Driven Ocean Upwelling

Surface-water displacement:
Stronger easterly trade winds push warm surface waters westward across the equatorial Atlantic and alter the distribution of ocean heat.

Cold water rises:
As surface waters are displaced, deeper, colder water can rise toward the surface through equatorial upwelling. This water is typically cooler and richer in nutrients than the surface layer.

The Atlantic Niña emerges:
When the resulting cooling is sufficiently strong and persistent, tropical Atlantic sea-surface temperatures can fall substantially below normal, producing the characteristic cold anomaly known as an Atlantic Niña.

The Atlantic cooling is therefore not an isolated ocean event. It can be part of a larger coupled atmosphere–ocean response initiated thousands of miles away in the Pacific.

The Atmospheric Shield: A Planetary Teleconnection Comes Full Circle

When a Pacific El Niño and an Atlantic Niña occur together, their effects can reinforce one another over the tropical Atlantic. But the hurricane response is only one part of a much larger planetary circulation story.

The sequence begins thousands of miles away:

Pacific El Niño
↓
Rerouted Walker circulation
↓
Planetary atmospheric teleconnection
↓
Atlantic pressure + wind changes
↓
Stronger trade winds
↓
Enhanced equatorial upwelling
↓
Atlantic Niña / cooler tropical Atlantic

The resulting Atlantic conditions can then influence tropical cyclone development.

El Niño tends to increase vertical wind shear, disrupting the organization of developing tropical cyclones. At the same time, cooler tropical Atlantic waters reduce the oceanic heat available to support deep convection and storm intensification.

Together, these effects can create an atmospheric shield over the Atlantic hurricane-development region:

ATLANTIC NIÑA
❄️ Cooler ocean
↓
Less convective energy

EL NIÑO
🔥 Pacific warming
↓
Stronger vertical wind shear

Combined effect
↓
Less favorable conditions for Atlantic tropical cyclones

This does not mean an Atlantic hurricane season becomes impossible. Tropical cyclone activity depends on many interacting factors, including sea-surface temperatures, atmospheric moisture, vertical wind shear, African easterly waves, upper-level circulation, and broader Atlantic climate conditions.

One Planetary System

The deeper significance is the connection itself.

A thermal anomaly in the Pacific can reorganize tropical convection. That atmospheric reorganization can propagate through the global circulation system, altering pressure and winds over the Atlantic. Those winds can change ocean upwelling and sea-surface temperatures. The resulting ocean anomaly can then modify atmospheric moisture, convection, and storm development.

The signal can extend even farther through the North Atlantic jet stream and atmospheric wave patterns, influencing weather regimes across Europe and the United Kingdom.

This is not a single atmospheric current traveling around the planet. It is a coupled network of atmospheric and oceanic responses operating across different spatial and temporal scales.

What begins as:

PACIFIC WARMING 🔥

can become:

ATMOSPHERIC REROUTING

then:

ATLANTIC COOLING ❄️

and ultimately:

REGIONAL WEATHER + HYDROCLIMATIC CONSEQUENCES

The climate system is therefore not a collection of isolated ocean basins and weather systems.

Energy moves through the connections.
The atmosphere carries the signal.
The oceans respond.
Feedbacks propagate.

One planet. One interconnected climate system.

Public Access Version

Tonight’s homework assignment is about climate chaos.

The climate system is chaotic. I started out researching the odd ENSO coupling — Pacific El Niño + Atlantic Niña. Usually, the Pacific and Atlantic pretty much “do their own thing.”

But this year is different.

The climate system has been supercharged with energy, and that energy is manifesting in some strange and surprisingly interconnected ways.

How Is Climate Energy Hitting You?
Rerouting the Walker Circulation

This is a story about teleconnections.

That proverbial butterfly wing flapping in the Pacific…
flutters across the atmosphere…
affects the USA…
and messes with the Atlantic.

At some point during this homework assignment, I thought to myself:

“I wonder if this teleconnection is… planetary?”

Does it hit Rocky Rex in the UK? 🇬🇧

A: Yes. Yes, it does.

And if you keep following the atmospheric energy and the feedbacks, you discover something even more interesting:

It isn’t just a Pacific–Atlantic connection.

It’s a planetary teleconnected climate system, where disturbances propagate through the atmosphere and oceans, affecting distant regions—and feeding back into the system.

One ocean warms.
The atmosphere responds.
The response travels.
The planet adjusts.

Homework continues… 🌎

by Daniel Brouse

Sudan: Hydroclimatic Whiplash and the Socio-Economic Feedback Loop

Sudan is experiencing more than a succession of extreme weather events. It is experiencing a coupled climate, ecological, and socioeconomic crisis in which each shock weakens the systems needed to absorb the next one.

Extreme heat increases water demand and accelerates soil and vegetation stress. Drought reduces agricultural productivity. Then intense rainfall arrives, producing flash floods that destroy crops, homes, roads, dams, and water infrastructure. Conflict magnifies the damage by degrading institutions, displacing populations, destroying infrastructure, and forcing people to rely more heavily on already-stressed natural resources.

The result is a reinforcing feedback loop:

Climate energy → hydroclimatic extremes → ecological degradation → economic losses → displacement and resource pressure → weakened infrastructure and institutions → greater vulnerability → larger impacts from the next climate extreme.

This is hydroclimatic whiplash interacting with socioeconomic vulnerability.

The Climate Shock Is Only the Beginning

A warmer climate does not simply produce more heat. Additional energy in the climate system can intensify the hydrological cycle, increasing atmospheric moisture demand while creating conditions for more intense precipitation when moisture is released.

Sudan is particularly vulnerable because millions of people depend directly or indirectly on rainfall, agriculture, groundwater, grazing lands, and fragile infrastructure.

A period of extreme heat and drying can therefore initiate a chain reaction. Heat increases evaporation and evapotranspiration. Soils lose moisture. Vegetation becomes stressed. Agricultural productivity declines. Water demand increases. Households and farmers draw more heavily on remaining water resources. Then, when intense rainfall arrives, degraded soils and damaged landscapes may have less capacity to absorb and retain water. Runoff increases. Flooding intensifies. Crops are destroyed. Infrastructure fails.

And the socioeconomic damage begins feeding back into the ecological system.

Hydroclimatic Whiplash

The most important feature is not simply that Sudan experiences droughts and floods.

It is the rapid alternation between them.

Prolonged heat and drying can be followed by intense, irregular rainfall. Communities already weakened by drought have fewer resources available to respond when flooding arrives.

This creates a compounding sequence:

Heat → drying → water scarcity → agricultural stress → poverty → reduced resilience → extreme rainfall → flooding → crop and infrastructure losses → displacement → increased resource pressure.

The same climate energy can therefore produce apparently opposite hazards—drought and flood, scarcity and excess—within the same broader system.

Ecological Degradation Becomes an Economic Feedback

Environmental degradation is not merely an ecological consequence of the crisis. It can become an amplifier of socioeconomic risk.

Vegetation provides natural protection against erosion, slows runoff, promotes infiltration, stores carbon, and helps moderate local temperatures.

When forests and other vegetation are removed, those ecological services decline.

In Khartoum, the loss of large areas of green cover has reduced natural buffering against heat and intense rainfall. Conflict and desperate resource extraction can accelerate this process as displaced and impoverished populations become increasingly dependent on local biomass for fuel and other necessities.

That creates another feedback:

Economic hardship → resource extraction → ecological degradation → greater climate vulnerability → larger economic losses → deeper hardship.

This is a classic reinforcing feedback loop.

The people most dependent on the natural environment are often the people least able to absorb its degradation.

Conflict Accelerates the Feedback

Sudan’s civil war dramatically increases the speed and severity of these feedbacks.

Conflict destroys roads, electrical systems, water infrastructure, health facilities, housing, agricultural assets, and government institutions. It also displaces people from established livelihoods and concentrates populations in places with limited resources.

The result is a reduction in adaptive capacity at precisely the moment climate volatility is increasing. A functioning society can respond to a flood by evacuating people, repairing roads, restoring electricity, treating contaminated water, rebuilding homes, and providing emergency food. A society experiencing war may be unable to do any of those things at sufficient scale. Consequently, the same physical climate event produces a much larger socioeconomic impact.

And that impact creates the conditions for the next crisis.

Water: The Central Feedback

Water connects nearly every component of Sudan’s crisis. Extreme heat increases atmospheric demand for moisture and raises human and agricultural water requirements. Drought reduces available water. Power failures can prevent wells and pumps from operating. Flooding can contaminate water supplies and damage water infrastructure. Displacement increases demand in receiving communities. Damaged infrastructure reduces distribution capacity. Unsafe water increases health risks. Illness reduces household productivity and increases economic stress. The system can therefore become self-reinforcing:

Heat → water demand → infrastructure stress → water scarcity → socioeconomic stress → reduced resilience → flood damage → contaminated water → health and economic losses.

Water is not simply another resource being affected by climate change. It is the connecting medium through which climate, ecology, infrastructure, health, agriculture, and economics interact.

Agriculture: Where Climate and Economy Collide

Agriculture is particularly sensitive to hydroclimatic whiplash.

Drought and extreme heat can reduce yields, deplete soil moisture, damage livestock, and consume seed reserves. Then intense rainfall can wash away soil, flood fields, destroy standing crops, and delay planting or harvesting.

A failed harvest has consequences beyond the farm. Food prices rise. Household purchasing power falls. Farmers lose income. Seed stocks decline. Livestock assets are depleted. Families sell productive assets to survive. Malnutrition increases. Migration and displacement accelerate. And the next growing season begins with fewer resources.

The feedback can therefore look like:

Climate shock → crop failure → income loss → asset depletion → reduced productive capacity → greater vulnerability to the next climate shock.

This is how a meteorological event becomes an economic event—and eventually a humanitarian event.

Displacement Creates New Ecological Pressure

Displacement adds another layer to the feedback system. People fleeing conflict or flooding must find food, water, shelter, fuel, and land. Large concentrations of displaced populations can place enormous pressure on surrounding forests, groundwater, agricultural land, and grazing areas. As resources become depleted, competition increases. Environmental degradation accelerates. Local livelihoods become less viable. More people become dependent on humanitarian assistance or migration.

The feedback therefore extends beyond individual households:

Extreme event → displacement → resource pressure → ecological degradation → livelihood loss → further displacement.

Climate vulnerability becomes socially transmissible.

The Collapse of Early Warning Capacity

Institutions are another component of the feedback loop. Effective meteorological services, flood monitoring, early-warning systems, emergency communications, and local governance can reduce the consequences of extreme weather. But conflict has severely weakened Sudan’s institutional capacity, including its ability to provide reliable meteorological information and early warnings.

That creates an important asymmetry:

The climate hazard can intensify faster than society’s capacity to respond to it.

When institutional capacity declines, the same amount of climate energy produces greater damage. Greater damage then further reduces institutional and economic capacity.

That is a reinforcing feedback.

The Socio-Economic Multiplier

The critical point is that climate change does not need to directly cause every component of Sudan’s crisis to substantially amplify it.

War is not caused by climate change. Poverty is not caused by climate change. Infrastructure destruction is not caused by climate change. But climate extremes can make each of these problems harder to manage.

Likewise, war, poverty, environmental degradation, and infrastructure failure do not cause climate change—but they can dramatically increase the damage produced by a given climate hazard.

This is why vulnerability matters. The physical climate signal enters a system that already contains feedbacks.

Those feedbacks determine how large the final impact becomes.

From Climate Energy to Human Consequences

Sudan provides a powerful example of how climate energy propagates through a coupled human-environment system.

The pathway is not simply:

Climate change → extreme weather → disaster.

It is closer to:

Climate energy
↓
Heat and hydroclimatic volatility
↓
Water and agricultural stress
↓
Ecological degradation
↓
Economic losses
↓
Displacement and resource pressure
↓
Infrastructure and institutional stress
↓
Reduced adaptive capacity
↓
Greater vulnerability
↓
Larger impacts from the next extreme event
↺

That final arrow is the most important part.

It turns a sequence of disasters into a feedback system.

Sudan as a Climate-Energy Feedback Experiment

Sudan demonstrates why climate risk cannot be understood through temperature records or individual disasters alone.

The important question is not simply:

How much hotter is it?

It is:

What does that additional energy do when it enters a stressed ecological and socioeconomic system?

In Sudan, it is interacting with water scarcity, extreme rainfall, agricultural vulnerability, environmental degradation, displacement, infrastructure failure, institutional collapse, and conflict.

Each component can reinforce the others.

The result is a system in which ecological degradation increases socioeconomic vulnerability, while socioeconomic stress accelerates ecological degradation.

Climate change supplies the additional energy.

Hydroclimatic whiplash supplies the shocks.

And the ecological and socioeconomic feedback loops determine how those shocks propagate through society.

That is how climate energy hits you.

Not as a single event.

As a cascade.

The Grand Canyon Flash Flood Tragedy

By Daniel Brouse

A devastating flash flood on August 29, 2026, tore through Grand Canyon National Park, leaving one person dead and approximately 15 people missing or unaccounted for. The disaster struck around 2:30 p.m. following intense rainfall on the Kaibab Plateau. Up to an inch of rain fell in just 20 to 30 minutes, sending an enormous surge of water cascading down the steep terrain into Bright Angel Canyon and the Phantom Ranch area.

The sudden deluge unleashed massive torrents that destroyed nearly every footbridge over Bright Angel Creek, forced the helicopter evacuation of more than 60 hikers and campers, and swept heavy boulders, trees, mud and metal debris into the Colorado River.

Emergency crews recovered the body of a 46-year-old man Sunday evening near Crystal Rapids.

This was not simply a lot of rain.

It was atmospheric water being converted into enormous amounts of kinetic energy in a matter of minutes.

And the conditions that made the landscape so vulnerable are increasingly being shaped by climate change.

Infrastructure and Park Impact

The flash flood caused severe and widespread damage to the inner canyon’s ecosystem and infrastructure.

Water Logistics: The flood ruptured the park’s critical water pipeline, forcing immediate water restrictions. Because the pipeline supplies essential water and fire-suppression capacity, overnight lodging within Grand Canyon National Park was suspended beginning August 31, 2026, while officials addressed the water emergency.

Transit Closures: The Colorado River was closed to river traffic because of hazardous floating debris and metal structures.

Trail Closures: The Black Bridge and Silver Bridge crossings of the Colorado River were closed, as was the North Kaibab Trail.

The destruction occurred extraordinarily quickly.

A few inches of atmospheric water falling over a few minutes became a moving wall of water, carrying enough energy to move massive rocks and debris, destroy bridges and fundamentally reshape portions of the canyon.

The Climate Connection

Monsoon storms are not new to the American Southwest. Flash floods have always occurred in the Grand Canyon. But saying that flash floods are natural does not mean climate change is irrelevant.

Climate change is altering the energy and moisture conditions under which these storms occur—and it is also altering the landscape through which that water moves.

As temperatures rise, the atmosphere can hold substantially more water vapor. The Clausius-Clapeyron relationship tells us that the atmosphere’s capacity to hold water vapor increases by approximately 7% for every 1°C of warming.

More atmospheric moisture means more potential precipitation energy available to intense storms. When that moisture is released rapidly through a powerful convective storm, enormous quantities of water can fall over a very small area in a very short period of time. That is exactly the kind of event that produces flash flooding in steep terrain.

But there is another part of the climate connection.

Wildfire Changes the Landscape

Climate change is also contributing to hotter, drier conditions and an increasingly dangerous wildfire environment across the American West. Wildfire strips vegetation from the landscape and can dramatically alter soil properties. Severe burns can leave soils far less capable of absorbing intense rainfall. Then the monsoon arrives.

Instead of rainfall being intercepted by vegetation and gradually infiltrating the ground, a much larger fraction can become rapid surface runoff.

The sequence becomes brutally efficient:

Heat → wildfire → vegetation loss → altered soils → intense rainfall → rapid runoff → flash flood → debris flow.

The National Park Service has specifically warned that areas affected by the Dragon Bravo Fire are particularly vulnerable to flash flooding and debris flows during monsoon storms.

This is where climate energy becomes visible.

When Climate Energy Becomes Kinetic Energy

The atmosphere supplies the water. The landscape supplies the gravitational potential. The canyon converts that potential energy into motion.

Rain falling on the Kaibab Plateau enters steep drainage channels. As the water rapidly descends toward Bright Angel Creek and the Colorado River, gravitational potential energy is converted into kinetic energy.

And the water begins carrying the landscape with it. Rocks. Boulders. Trees. Sediment. Mud. Ash. Metal. Infrastructure.

The result is a fluidized mass capable of enormous destructive force.

A rainfall event lasting only 20 or 30 minutes can therefore produce geological-scale consequences.

Atmospheric energy becomes hydrologic energy.
Hydrologic energy becomes gravitational energy.
Gravitational energy becomes kinetic energy.
Kinetic energy becomes destruction.

That is the physics of the event.

Climate Change Doesn’t Have to Create the Hazard

One of the most important points about climate attribution is that climate change does not have to invent a completely new type of weather event to make the event more dangerous. The Grand Canyon has always experienced monsoons. It has always experienced flash floods. It has always experienced erosion.

But climate change can change the background state of the system.

A warmer atmosphere can contain more moisture. Hotter and drier conditions can increase wildfire risk. Wildfires can remove vegetation and alter soils. A burned watershed can produce much faster runoff. And when extreme precipitation arrives, the same amount of rain—or potentially more rain—can produce a substantially different physical response.

The climate system is therefore not merely changing the weather.

It is changing the conditions under which weather interacts with the landscape.

Hydroclimatic Whiplash

This is one expression of hydroclimatic whiplash: rapid transitions between extreme drying and extreme wetting as increasing climate energy moves through the hydrological cycle.

First comes heat and drying. Then wildfire. Then atmospheric moisture. Then extreme precipitation. Then runoff. Then erosion and debris flows. The landscape can go from severely water-stressed to violently inundated in a matter of hours.

That is the whiplash.

And the Grand Canyon provides an almost perfect natural laboratory for watching the process unfold because steep terrain concentrates and accelerates the movement of water.

The Bigger Picture

The August 29 tragedy is therefore more than another isolated weather disaster. It is a powerful example of how climate energy can move through a coupled atmosphere-landscape system. The atmosphere held the moisture. The storm released it. The burned and altered landscape failed to absorb it. Gravity accelerated it. The canyon concentrated it.And the resulting kinetic energy moved rocks, debris and infrastructure toward the Colorado River.

One person died. Approximately 15 people remained missing or unaccounted for. More than 60 people had to be evacuated by helicopter. Bridges were destroyed. Trails were closed. The Colorado River was closed to river traffic. Critical water infrastructure was ruptured. And the landscape itself was reshaped.

This is what climate change looks like when you follow the energy.

It is not just a number on a temperature chart. It is not just a rising global average. It is not just another hotter summer.

Climate energy moves.

It moves through the atmosphere as heat and moisture.

It moves through storms as precipitation.

It moves through watersheds as runoff.

It moves downhill as gravitational energy.

And eventually, it becomes kinetic energy powerful enough to move boulders, destroy bridges and sweep human beings away.

The Grand Canyon has always been a place where the forces of geology are visible.

On August 29, 2026, those forces became brutally visible again.

Climate change didn’t create the Grand Canyon flash flood—it amplified the energy that drove it.

A warmer, more energetic climate can make the atmospheric and landscape conditions that produce such disasters more extreme.

And when that energy is released all at once, the question is no longer simply:

How much rain fell?

The more important question is:

How much energy did that rain unleash?

That is How Is Climate Energy Hitting You?

In the Grand Canyon, on August 29, 2026, the answer was:

As a wall of water, rock, mud and debris moving through the canyon with enough energy to destroy almost everything in its path.

by Daniel Brouse

The permafrost tipping point—and its feedbacks with other tipping points—is the most interesting part to me. Permafrost was kind of the glue holding everything together… until 1.5°C. Then the coupled feedbacks start feeding each other, and the whole system begins to unravel. And the mountains crumble to the sea… see? 😉

The Energy That Moves Mountains

• The Mountains Crumble to the Sea
• Nepal–Tibet: Glacier Loss, Permafrost Collapse, Glacial Lake Outburst Floods, Flash Floods, Mudslides and Avalanches
• The Nepal-Tibet Domino Effect: A Continuous Cascade of Failures
• Nepal-Tibet: Energy Like Wet Concrete
• Nepal-Tibet: Fluidization Physics
• Observe Tipping Points Topple → Climate Change Avalanche
• The Physics of When the Earth Starts Moving

The Backyard Experiments: Hydroclimatic Whiplash, Soil Degradation, Insect Decline, and Ecosystem Collapse

By Daniel Brouse

Have You Looked Out Your Back Door for Climate Change?

It’s there.

I noticed an interesting phenomenon: an increase in dead earthworms and millipedes in the swimming pool.

It turns out this is connected to opposite extremes of a coupled feedback loop.

Too wet. Then too dry. Then too wet. Then too dry.

That is hydroclimatic whiplash, and it was destroying the ecosystem that is my backyard.

What initially appeared to be two unrelated observations—earthworms at the bottom of the swimming pool after extreme rainfall and millipedes at the bottom during periods of intense drying—began to look like two sides of the same climate-energy problem: too much water, followed by too little.

The backyard was being hit from both directions.

---

TOO MUCH WATER

Earthworms commonly move toward the soil surface when soils become saturated. Heavy rainfall can produce much larger and more rapid changes in soil moisture and oxygen availability than gentle, prolonged rainfall.

The swimming pool then becomes an accidental trap.

The basic sequence is remarkably simple:

[Extreme Rainfall] → [Soil Saturation + Oxygen Stress] → [Surface Migration] → [Accidental Pool Entry]

Once an earthworm reaches the pool deck, there is little it can do to escape the water.

What begins as a survival response to changing soil conditions can therefore end with a dead worm in the pool.

But the earthworms were only the visible part of a much larger biological response occurring beneath the surface.

See: West Chester, Pennsylvania: Hydroclimatic Whiplash and Urban Flooding — Unfortunately, Worms Can’t Swim

---

TOO LITTLE WATER

Millipedes are fundamentally creatures of moist microhabitats.

They live in leaf litter, soil, rotting wood, and other environments where humidity remains relatively high. Their survival depends on maintaining water balance in an environment that is normally protected from direct solar heating and rapid atmospheric drying.

When extreme evaporative demand suddenly arrives, that microclimate can collapse.

The same atmospheric conditions that pull extraordinary amounts of water from a swimming pool can also pull moisture from the soil and leaf litter where millipedes live.

Extreme evaporative demand amplifies evapotranspiration, a core component of Earth’s climate system that links soil, vegetation, and atmosphere through continuous water and energy exchange.

The resulting feedback can be expressed as:

[Increased Evaporative Demand] → [Soil & Litter Drying] → [Vegetation Stress] → [Habitat Loss] → [Insect & Soil-Organism Decline]

And once vegetation begins to disappear, another feedback can emerge:

[Reduced Vegetation] → [Reduced Transpiration] → [Reduced Atmospheric Moisture Recycling] → [Reduced Rainfall] → [Increased Drought] → [Further Vegetation & Insect Loss]

The landscape begins losing the biological machinery that helped regulate its own water cycle.

See: West Chester, Pennsylvania: Hydroclimatic Whiplash and Flash Droughts — Unfortunately, Millipedes Can’t Swim

---

THE CLIMATE ENERGY OF HYDROCLIMATIC WHIPLASH

Soil Worth Dirt

Soil is alive.

Hydroclimatic whiplash kills it.

Extreme rainfall can cause erosion, nutrient loss, oxygen stress, physical disruption, and mortality among soil organisms.

Extreme drying can produce an entirely different set of stresses: dehydration, vegetation loss, declining microbial activity, loss of organic matter, and collapse of moisture-dependent habitat.

This was evident across the soil layers in my backyard:

Epigeic — Surface Dwellers

Endogeic — Shallow Soil Dwellers

Anecic — Deep Burrowers

Both too much rain and not enough rain resulted in mass casualties within the same week—and on multiple occasions during a single season.

That is not simply a wet-dry cycle.

It is an ecological stress cycle.

The soil receives an extreme pulse of water, followed by extreme atmospheric demand for water.

Then the process repeats.

The organisms living in the soil are caught between extremes.

---

WHEN SOIL DIES

When soil dies, it undergoes desertification.

Desertification is the transformation of productive, biologically functioning land into degraded land with declining capacity to support vegetation and ecosystem processes.

As soil loses organic matter, biological activity, structure, and water-holding capacity, it becomes increasingly vulnerable to erosion and drying.

The feedback is vicious:

[Extreme Rainfall] → [Erosion & Soil-Organism Loss] → [Vegetation Decline] → [Less Soil Protection] → [More Erosion]

At the opposite extreme:

[Extreme Heat & Evaporative Demand] → [Soil Drying] → [Vegetation Stress] → [Vegetation Loss] → [Reduced Soil Organic Matter] → [Reduced Water Retention] → [Greater Drying]

The two pathways eventually converge.

The soil loses its ability to hold water.

When soil can no longer retain water effectively, rainfall increasingly becomes runoff rather than stored moisture. When the atmosphere demands water, there is less moisture available to sustain vegetation. The result is a landscape increasingly vulnerable to both flooding and drought.

That is the climate paradox of degraded soil:

Too much water can destroy its structure.

Too little water can destroy its biology.

Repeatedly alternating between the two can destroy its resilience.

As this process advances, the land can cross from a productive biological system into a degraded one.

That is desertification.

And once the soil’s biological engine begins to fail, its capacity to sequester and store carbon declines as well.

The climate feedback then becomes even more serious:

[Soil Degradation] → [Reduced Carbon Storage] → [More Atmospheric CO2] → [Additional Warming] → [Greater Evaporative Demand] → [More Soil Degradation]

Soil therefore acts as both a carbon reservoir and a climate buffer.

Destroy the soil, and you weaken both.

---

BACKYARD PHYSICS

The backyard observations can be connected to fundamental physical relationships governing Earth’s water and energy cycles.

Two of the most important are the Clausius–Clapeyron relationship and the Penman combination equation.

The Clausius–Clapeyron relationship describes how saturation vapor pressure changes with temperature.

The Penman combination equation describes how available surface energy and atmospheric drying conditions combine to determine evaporative demand.

Together, they help explain the physics behind extreme evaporation.

---

THE CLAUSIUS–CLAPEYRON RELATIONSHIP

The Clausius–Clapeyron relationship describes the temperature dependence of saturation vapor pressure.

In differential form:

d(e_s)/dT = (L_v × e_s) / (R_v × T²)

where:

• e_s = saturation vapor pressure
• T = absolute temperature in kelvins
• L_v = latent heat of vaporization
• R_v = specific gas constant for water vapor

Dividing both sides by e_s gives:

(1/e_s) × (d(e_s)/dT) = L_v / (R_v × T²)

Under typical near-surface atmospheric temperatures, this relationship corresponds approximately to a 7% increase in saturation vapor pressure per 1°C of warming.

In other words, a warmer atmosphere has a substantially greater capacity to contain water vapor before reaching saturation.

That increased capacity matters because it can increase the atmospheric demand for evaporation when water is available.

---

EXTREME EVAPORATION

For an open water surface such as a swimming pool, evaporation depends on several interacting variables.

A useful framework is the Penman combination equation, which incorporates both the available energy at the surface and aerodynamic drying.

One common form is:

λE = [Δ(R_n − G) + ρ_a × c_p × (e_s − e_a) / r_a] / (Δ + γ)

where:

• λE = latent heat flux associated with evaporation
• Δ = slope of the saturation vapor pressure curve
• R_n = net radiation
• G = ground or substrate heat flux
• ρ_a = air density
• c_p = specific heat capacity of air
• e_s = saturation vapor pressure
• e_a = actual vapor pressure
• r_a = aerodynamic resistance
• γ = psychrometric constant

The equation contains two major physical components.

1. Available Energy

The term:

Δ(R_n − G)

represents the energy available at the surface to drive evaporation.

Greater available energy generally means greater potential evaporation when sufficient water is available.

2. Aerodynamic Drying

The term:

ρ_a × c_p × (e_s − e_a) / r_a

represents the aerodynamic component.

The difference:

e_s − e_a

is the vapor pressure deficit (VPD).

A larger VPD means the atmosphere is farther from saturation and therefore has greater capacity to remove water from a wet surface.

Wind increases turbulent exchange and continually replaces moist air near the evaporating surface with drier air.

The result can be extreme evaporation.

---

WHERE THE PHYSICS MEETS THE BACKYARD

The connection between temperature, atmospheric moisture, and evaporation can be represented as:

[Higher Temperature] → [Higher Saturation Vapor Pressure] → [Potentially Higher VPD] → [Greater Atmospheric Drying Demand]

At the same time:

[Higher Available Energy] + [Greater Atmospheric Drying Demand] → [Greater Potential Evaporation]

A swimming pool has an abundant supply of water.

So when atmospheric evaporative demand increases, the water can continue evaporating.

Soil is different.

Once soil moisture becomes limited, evaporation can become water-limited, even while atmospheric evaporative demand remains extremely high.

This creates a critical climate paradox:

The atmosphere can become increasingly thirsty while the landscape becomes increasingly dry.

---

THE BACKYARD AS A CLIMATE SENSOR

The dead earthworms and millipedes in my swimming pool are not, by themselves, proof of climate change.

They are observations of biological responses to environmental conditions.

But observations become scientifically meaningful when they are connected to measurable physical mechanisms.

The backyard contains a miniature version of the larger climate system:

RAIN

↓

SOIL SATURATION

↓

BIOLOGICAL RESPONSE

↓

SURFACE WATER

↓

SOLAR ENERGY

↓

EVAPORATION

↓

ATMOSPHERIC MOISTURE

↓

SOIL DRYING

↓

VEGETATION STRESS

↓

HABITAT LOSS

↓

ECOSYSTEM STRESS

Then the rain comes again.

And the cycle starts over.

---

HYDROCLIMATIC WHIPLASH

The climate problem is not simply that the world is becoming warmer.

It is that warming can alter the intensity, timing, and interaction of water-cycle extremes.

A landscape can experience:

Extreme Rain → Saturation → Flooding → Erosion

followed by:

Extreme Heat → High VPD → Evaporative Loss → Drought

followed again by:

Extreme Rain → Runoff → Erosion → Soil Disruption

followed again by:

Extreme Drying → Vegetation Stress → Habitat Loss

The ecological damage can accumulate even when each individual event is temporary.

The ecosystem does not necessarily get enough time to recover before the next extreme arrives.

That is what makes hydroclimatic whiplash so dangerous.

---

FROM THE SWIMMING POOL TO THE PLANET

Though a swimming pool is not a climate model, it is an excellent reminder that climate physics is not abstract.

It operates in the backyard.

It operates in the soil.

It operates in the leaf litter.

It operates in every evaporating puddle.

It operates in every plant releasing water vapor through transpiration.

And it operates in every organism struggling to maintain its water balance as environmental conditions swing between extremes.

The physics begins with energy.

Solar energy warms surfaces.

That energy can become latent heat as water changes phase.

Temperature affects saturation vapor pressure.

Atmospheric dryness creates evaporative demand.

Water availability determines whether that demand can actually be met.

And biological systems respond to the resulting changes in moisture, temperature, oxygen, habitat, and food availability.

That is climate energy hitting the backyard.

Sometimes it arrives as too much water.

Sometimes it arrives as too little.

And sometimes the greatest damage comes from the violent transition between the two.

---

THE LESSON FROM THE POOL

The next time you find an earthworm or millipede in the swimming pool, don’t just ask:

“How did it get here?”

Ask:

“What was happening to the ecosystem before it got here?”

Because sometimes the most visible evidence of a changing climate isn’t in a satellite image or a global temperature graph.

Sometimes it is floating in the swimming pool.

And sometimes the smallest casualties are telling us something much larger:

The climate system is not merely changing the temperature.

It is changing the movement of water.

And when water extremes begin arriving faster than ecosystems can recover, the consequences can reach all the way down to the soil beneath our feet.

by Daniel Brouse

Why are millipedes showing up dead at the bottom of the swimming pool?

The answer may seem strange at first: extreme weather is changing the moisture dynamics of the tiny ecosystem around your home.

Earlier this summer, I wrote about earthworms turning up dead in the pool. Their appearance followed intense rainfall after several dry days—a small example of climate-change-driven hydroclimatic whiplash.

After prolonged dryness, intense rainfall can rapidly saturate the soil and displace oxygen from the pore spaces. Earthworms respond by moving toward the surface, where oxygen is more readily available. But when the surface is saturated, they can still be trapped in an inhospitable environment. As they search for better conditions, some ultimately end up in the swimming pool.

See: Urban Flooding — Unfortunately, Worms Can’t Swim

Millipedes are responding to the opposite extreme.

They are showing up after several days without rain, particularly during periods of unusually rapid evaporation. In my backyard, the microclimate can swing from flash rainfall to flash drought within a day or two.

And those swings matter.

When a Swimming Pool Becomes an Evaporation Gauge

Under ordinary summer conditions, a pool might lose roughly 0.25 to 0.5 inches of water per day, depending on temperature, humidity, wind, solar radiation, pool temperature, and other factors.

During the recent extreme conditions, however, evaporation appeared to approach an inch per day—roughly two to four times a typical baseline.

That isn’t simply a story about hotter temperatures.

It is a story about energy and atmospheric demand for water.

The Clausius-Clapeyron relationship is a fundamental principle of thermodynamics. As temperature rises, the atmosphere’s saturation vapor pressure increases by roughly 7% per °C. A warmer atmosphere can therefore support substantially more water vapor.

But Clausius-Clapeyron alone does not explain a localized three- or four-fold increase in evaporation.

The missing piece is the interaction between temperature and the atmosphere’s ability to remove water from the surface.

The Physics of Extreme Evaporation

For an open water surface, evaporation depends on several interacting variables. A useful framework is the Penman combination equation, which incorporates both the available energy at the surface and aerodynamic drying:$$E = \frac{\Delta(R_n-G)+\gamma f(u)(e_s-e_a)} {\Delta+\gamma}$$

The important point is that evaporation is not controlled by temperature alone.

Three major factors can amplify water loss:

1. Vapor Pressure Deficit

The difference between the saturation vapor pressure at the water surface and the actual vapor pressure of the surrounding air is the vapor pressure deficit (VPD):$$VPD=e_s-e_a$$

When hot, dry air moves over a pool, VPD can become very large.

The water surface is effectively surrounded by air with a strong capacity to accept additional water vapor.

That creates a powerful evaporative gradient.

2. Wind

The aerodynamic term, $f(u)$, represents the influence of wind.

Immediately above a pool is a thin boundary layer of relatively humid air. Wind continually removes that moist layer and replaces it with drier air.

Think of it as nature’s hair dryer.

The stronger the atmospheric mixing, the more efficiently water vapor is transported away from the surface.

3. Solar Radiation

Net radiation, $R_n$, supplies energy to the system.

Strong, cloudless sunlight transfers energy into the pool and surrounding surfaces. As the water warms, its saturation vapor pressure rises, increasing the potential for evaporation.

The result is not simply:

hotter = more evaporation.

It is:

heat + solar energy + dry air + wind = dramatically increased evaporative demand.

Visualizing the Whiplash Surge

During a normal summer week, these variables remain within a relatively familiar range.

But during hydroclimatic whiplash, they can change rapidly.

A sequence might look like this:

Dry period → intense rainfall → saturated soil → rapid drying → heat → low humidity → high VPD → wind → extreme evaporation

The same landscape can therefore move from waterlogged to severely moisture-stressed within days.

That is the physical signature of hydroclimatic whiplash.

The swimming pool becomes an unintended local measuring device for that atmospheric forcing.

The Pool as a Heat Sink

There is another interesting component: the pool’s thermal mass.

Water has a high heat capacity. After cool nights, the pool can retain substantial stored thermal energy. When brutally hot, dry air moves over that relatively warm water, the temperature and vapor-pressure gradients can become especially favorable for evaporation.

The atmosphere is essentially pulling moisture out of the pool while the pool supplies some of the energy required to make that phase change possible.

That is why an isolated observation of “one inch of evaporation” should not automatically be interpreted as a simple temperature effect.

It is the result of an energy-balance and mass-transfer process—and these are precisely the weather conditions we have been experiencing.

And that brings us back to the millipedes.

Evapotranspiration and the Penman Combination Equation

In hydrology and climate science, evapotranspiration (ET) is the standard term for the combined movement of water from the land surface into the atmosphere through soil evaporation and plant transpiration.

The topsoil experiences a process similar to what happens at the surface of a swimming pool. When the atmosphere becomes hot, dry, and windy, the vapor pressure deficit (VPD) increases, strengthening the gradient that drives water from the surface into the atmosphere:

Low humidity → high VPD → wind → extreme evaporation

But the process does not stop at the surface. Transpiration draws water from deeper in the soil through plant roots and transports it upward through the plant, where it exits as water vapor through microscopic pores called stomata.

During periods of extreme heat and atmospheric dryness, this combined evaporative demand can rapidly deplete available soil moisture, increasing water stress on vegetation and accelerating the drying of the entire soil–plant system.

The result is a powerful feedback:

Heat + dry air → higher VPD → increased evapotranspiration → declining soil moisture → greater vegetation stress

See: Transpiration, Atmospheric Moisture Recycling, and Climate-Driven Heat Stress in a Warming World 

The Millipede Problem

Millipedes are fundamentally creatures of moist microhabitats.

They live in leaf litter, soil, rotting wood, and other environments where humidity remains relatively high. Their survival depends on maintaining water balance in an environment that is usually protected from direct solar heating and rapid atmospheric drying.

When extreme evaporative demand suddenly arrives, that microclimate can collapse.

The same atmospheric conditions that pull an extraordinary amount of water from a swimming pool can also pull moisture from the soil and leaf litter where millipedes live.

1. The Desiccation Trap

Millipedes are vulnerable to water loss because their bodies are not as well protected against desiccation as those of many terrestrial arthropods.

During periods of high VPD, water is lost more rapidly to the surrounding atmosphere.

The drier the air becomes, the stronger the gradient driving water out of the animal.

For a moisture-dependent organism, that can quickly become a physiological crisis.

2. Microclimate Collapse

Millipedes normally exploit the humid boundary layer beneath leaves, moss, vegetation, and decaying organic material. That tiny environment can be dramatically different from the air temperature and humidity measured a few feet above the ground. But extreme evaporation changes that.

As soil and vegetation dry, the humid refuge beneath the vegetation becomes progressively less effective. The millipedes are then faced with a choice:

Stay and desiccate—or move.

So they move. They may retreat deeper into soil, beneath logs, or into other remaining pockets of moisture. But when those refuges become unsuitable, some millipedes emerge and begin searching for a new moist environment.

3. Their Food Supply Dries Out

Millipedes are primarily detritivores. They feed on decaying plant material, leaf litter, fungi, and other organic matter.

That food web also depends on moisture.

When leaf litter becomes severely dried out, the physical and biological processes that make organic material available to decomposers and detritivores can be disrupted.

The result is a double problem:

The habitat is drying out—and the food system is changing with it.

4. The March Begins

This is where the swimming pool becomes relevant. A millipede doesn’t understand what a swimming pool is. It responds to its immediate environment. When its normal habitat becomes dangerously dry, it searches for a more favorable moisture environment.

A swimming pool represents an enormous source of water compared with the surrounding dry landscape.

Unfortunately for the millipede, a pool is a moisture sink but not a safe habitat. Once it reaches the water, the outcome can be fatal.

Millipedes are not strong swimmers. They can become trapped at the water’s edge, fall into the pool, and drown.

What appears to be a bizarre invasion of millipedes may therefore be the final stage of a much larger environmental chain.

Climate Energy Has a Marching Order

The important point isn’t that climate change “created” millipedes or directly ordered them into the swimming pool.

It is that changes in atmospheric energy and moisture transport can reorganize the physical environment in which they live.

The sequence looks something like this:

Heat → higher atmospheric moisture demand → higher VPD → increased evaporation → drying vegetation and soil → microclimate collapse → millipede migration → swimming pool

At the other extreme:

Dry period → intense rainfall → saturated soil → reduced pore-space oxygen → earthworm emergence → swimming pool

Same backyard.

Different extreme.

Opposite moisture conditions.

And both can produce the same strange result:

dead creatures at the bottom of the pool.

That is what makes hydroclimatic whiplash so interesting. Climate change isn’t always experienced as a dramatic hurricane, wildfire, or flood. Sometimes it arrives as something much smaller.

Sometimes it is measured in inches of water disappearing from your swimming pool.

And sometimes, if you pay attention, the millipedes get their marching orders.

by Daniel Brouse

The Climate Physics Behind the Nepal-Tibet Collapse

“Warming of Nepal’s glaciers has been a continuous process over this timescale and is not something that has only occurred recently due to human activity.”

This statement is misleading and, as a description of the modern climate system, demonstrably wrong.

Yes, Himalayan glaciers have always experienced natural fluctuations. Glaciers advance and retreat. Temperatures and precipitation have varied throughout Earth’s history. But that fact does not explain away the rapid warming and cryospheric changes occurring today, nor does it establish that recent warming is natural.

The relevant question is not whether Nepal’s glaciers have ever warmed before. The question is whether the recent warming that is altering the glaciers, permafrost, precipitation, and meltwater system is being driven by human greenhouse-gas emissions. The evidence for the human contribution to modern global warming is overwhelming.

A primary climate-related mechanism relevant to an event like this is the intensification of the water cycle. For every 1°C of warming, the atmosphere can hold approximately 7% more water vapor, increasing the potential for heavier precipitation when that moisture is released. This is a consequence of the Clausius-Clapeyron relationship, not a theory about this particular glacier.

That matters because water is not simply something that falls from the sky and runs downhill. In a glacierized mountain system, water can infiltrate snow and ice, penetrate fractures, reach the glacier bed, enter surrounding sediment and rock, and increase water pressure. Under the right conditions, that can reduce friction and increase the mobility of ice and unstable material.

The area around the collapse has also experienced rainfall and substantial meltwater and basal-water flow. Those observations are important because they provide a plausible physical pathway connecting atmospheric warming and precipitation changes to the mechanical stability of the glacier and surrounding terrain. However, demonstrating that this particular collapse was caused by human climate change requires event-specific observations and attribution analysis; the physics establishes the mechanism, not by itself the precise contribution of each factor.

Warming also contributes to glacier mass loss and can thaw permafrost and permanently or seasonally frozen ground that helps stabilize steep mountain terrain. These processes can weaken the physical structure of the landscape while increasing the amount of liquid water moving through it.

So the connection to human activity isn’t simply, “It got warmer, therefore the glacier collapsed.” The physics is much more interesting—and much more complicated.

Human greenhouse-gas emissions have increased atmospheric and surface temperatures. That warming affects the cryosphere and hydrological cycle. More heat can increase ice melt. A warmer atmosphere can carry more moisture. Precipitation can deliver additional water to an already destabilized system. Meltwater can infiltrate ice and rock, increase water pressure, and alter friction. Thawing frozen ground can reduce slope stability.

Those changes can help load the system toward failure.

The collapse itself is a gravitational event. Gravity supplies the immediate energy that drives the mass downward. The climate connection lies in how human-caused warming can alter the physical conditions under which that gravitational energy is released.

And once the mass begins moving, another fascinating piece of physics takes over: water can actually make a moving granular system more mobile.

We generally think of water as something that slows things down. But water under pressure between particles can reduce the friction holding those particles together.

In simplified form:

σ′ = σ − u

where σ′ is effective stress, σ is total stress, and u is pore-water pressure.

As pore-water pressure rises, effective stress falls. As effective stress falls, frictional resistance can decrease. That can make a slope or debris mass substantially more mobile.

This is one reason a wet, saturated mass can behave so differently from the dry rock, soil, and ice from which it originated. The material does not literally turn into water. Instead, water becomes part of a coupled solid-fluid system in which fluid pressure can support and mobilize solid particles.

Under sufficiently energetic and saturated conditions, a granular mass can become partially fluidized, allowing it to flow and transport enormous quantities of additional material.

That is the “wet concrete” effect.

And it provides an important way to understand the collapse: climate change does not need to physically push the mountain downhill. It can alter the water, ice, temperature, and ground conditions that help determine when a mountain becomes capable of moving.

Then gravity does the rest.