by Daniel Brouse

🏔️ SIMPLIFIED INTRODUCTION: MOUNTAIN GLACIERS AT THE EDGE

Mountain glaciers are disappearing faster.

But the bigger danger may be what happens to the mountains when the ice disappears.

Record global heat and the powerful 2023–2024 El Niño helped drive extraordinary glacier mass loss worldwide. Now, with another potentially powerful El Niño developing against an already overheated climate, the consequences extend far beyond shrinking glaciers.

Extreme heat melts glacier ice.

Permafrost thaws.

Mountain slopes weaken.

Rain replaces snow.

Atmospheric rivers deliver enormous amounts of water.

Landslides block rivers.

Temporary lakes form.

And those lakes can suddenly burst downstream.

The danger is no longer simply ICE LOSS.

It is SYSTEM INSTABILITY.

This is what happens when multiple climate-sensitive systems begin moving together—and feedbacks start turning one disturbance into another.

Tipping Point Season: Mountain Glaciers at the Edge

The mountain isn’t just losing ice.

The mountain is changing.

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The Full Report

The combination of the powerful 2023–2024 El Niño and record-breaking global heat severely accelerated the loss of mountain glaciers worldwide, producing some of the largest glacier mass-balance deficits ever recorded. What makes this period particularly important is not simply the amount of ice being lost, but the way extreme heat, altered precipitation, permafrost thaw, and increasingly volatile hydrology are beginning to interact across high-mountain environments.

2023–2024: A Global Glacier Mass-Loss Shock

Data compiled by the World Glacier Monitoring Service (WGMS) and the United Nations illustrate the extraordinary scale of recent glacier deterioration. The compounding effects of human-induced climate change and the 2023–2024 El Niño contributed to exceptionally severe melting conditions.

Record-breaking global mass loss

During the 2023 hydrological year, glaciers experienced a record-breaking global mass loss equivalent to approximately 1.1 meters of ice thickness. The total loss was roughly 600 gigatons of water, making 2023 the largest annual glacier mass loss recorded since systematic measurements began in 1976.

The deterioration continued in 2024. The 2024 hydrological year ranked as the fourth-worst year on record, with glaciers losing another approximately 450 billion tonnes of ice. It also marked the third consecutive year in which all 19 glacier regions monitored globally experienced a net mass loss.

The significance of these numbers extends beyond the glaciers themselves. Mountain glaciers function as frozen reservoirs, storing water that is gradually released into downstream river systems. Their rapid depletion therefore represents both a cryospheric transformation and a growing threat to water security, ecosystems, agriculture, hydropower, and communities downstream.

Tropical Glaciers: Exceptionally Vulnerable

Tropical glaciers, particularly those in the Andes and Indonesia, are exceptionally sensitive to changes in precipitation and temperature. The 2023–2024 El Niño amplified those vulnerabilities.

In the Peruvian Andes, research on the Quelccaya Ice Cap has shown how El Niño can suppress wet-season snowfall, replacing it with warmer and drier conditions. Fresh snow normally provides a highly reflective surface that returns much of the incoming solar energy back to space. When snowfall fails and bare glacier ice is exposed, the darker surface absorbs substantially more solar energy.

This creates a powerful feedback: less snowfall means less reflective snow cover; less reflective snow means greater absorption of solar energy; greater energy absorption accelerates melting and exposes still more bare ice.

Indonesia’s Puncak Jaya glaciers face an even more precarious future. These rare tropical glaciers were already critically endangered, and drought and temperature anomalies associated with El Niño accelerated the timeline toward potential disappearance.

European Alps and North American Ranges

El Niño does not directly control the climate of every mountain region. Its effects are superimposed on a much larger background trend of human-driven global warming.

In the European Alps, persistent and intense summer heatwaves produced severe glacier degradation. Melting occurred even at elevations above approximately 3,100 meters—heights that historically provided substantially greater protection from summer heat.

The North Cascades of the United States experienced a similar pattern. In areas such as North Cascades National Park, monitored glaciers continued to lose mass through both 2023 and 2024, consistent with a broader regional trend in which glacier melt rates have increased dramatically over recent decades.

The important signal is therefore not simply that glaciers are retreating. It is that the elevation, duration, and intensity of melting are changing. Ice that once remained protected through the summer is increasingly being exposed to temperatures capable of transforming both the surface and the internal structure of mountain glaciers.

The 2023–2024 Glacier Signal

Metric / Region	Impact from 2023–2024 Heat and El Niño
Global Mass Loss	2023 was the worst year on record, with approximately 600 Gt of ice lost. 2024 ranked fourth-worst. All 19 monitored glacier regions experienced net loss.
Tropical Glaciers	Reduced seasonal snowfall combined with extreme heat exposed darker bare ice, accelerating thinning and shortening extinction timelines.
Mid-Latitude Glaciers	Extreme high-elevation temperatures pushed the melt zone upward, exposing previously protected ice to rapid melting, fracturing, and structural deterioration.
Sea-Level Contribution	Glacier mass loss adds freshwater directly to the oceans, compounding sea-level rise driven by thermal expansion and other sources.

But the story does not end with glacier retreat.

The more consequential question is what happens when a warming atmosphere begins to destabilize the mountains surrounding and supporting those glaciers.

2026–2027: From Glacier Loss to Mountain Instability

The emerging 2026–2027 El Niño is occurring against an already unprecedented background of global warming. If the event develops with the exceptional strength currently being discussed, its influence will not be confined to ocean temperatures or atmospheric circulation.

High-mountain environments are particularly vulnerable because they sit at the intersection of several climate-sensitive systems: glaciers, snowpack, permafrost, steep rock faces, atmospheric circulation, and rapidly responding river networks.

The result can be a chain reaction in which one disturbance increases the probability or severity of another.

1. The Nepal–Tibet Glacial Collapse

The catastrophic disaster reported along the Nepal–Tibet border on August 26, 2026, provides a stark example of how extreme heat can intersect with high-altitude geological instability.

A massive section of glacier collapsed at approximately 5,200 meters, triggering an enormous avalanche of ice, rock, and mud that moved into the Trishuli and Bhotekoshi River valleys. The resulting destruction affected communities and critical infrastructure, including hydropower facilities and border transportation routes.

The thermal environment preceding the collapse is particularly significant. Meteorological analysis reportedly found prolonged and exceptional warmth at the elevation of the glacier, with temperatures averaging approximately 5°C (41°F) over a six-day period. Such temperatures are extraordinary at 5,200 meters and illustrate how extreme atmospheric warmth can penetrate environments historically protected by elevation.

The lesson is larger than a single glacier failure.

When temperatures rise far enough, high altitude is no longer the same form of protection it once was.

2. Feedback Mechanism: Permafrost Thaw and Slope Failure

Glacier retreat is only one component of high-mountain destabilization. Permafrost provides another critical structural control.

Permafrost consists of permanently frozen soil, rock, and ice. In steep mountain terrain, frozen water can act as a form of geological glue, binding fractured rock and stabilizing slopes.

Extreme warming attacks that structural support.

As temperatures rise, permafrost can thaw progressively deeper into mountain slopes. Ice within fractures melts, reducing the cohesion between rock surfaces. Water can then penetrate deeper into the fractured rock, while repeated freeze-thaw cycles and changing hydraulic pressures further weaken the structure.

The result can be slope failure.

A destabilized glacier, hanging ice mass, or fractured rock face may collapse as a single event, but the material released does not necessarily remain an avalanche of ice. It can entrain enormous quantities of rock, soil, sediment, and meltwater.

What begins as a glacier or rock failure can therefore become a high-speed debris flow or mudslide carrying millions of tonnes of material downstream.

This is a critical transition: climate change is not simply removing ice from mountains; it can alter the mechanical stability of the mountains themselves.

3. Feedback Mechanism: Supersized Atmospheric Rivers

The other half of the problem is water.

El Niño reorganizes global atmospheric circulation and changes the distribution of heat and moisture across the planet. Warmer ocean surfaces provide greater evaporation potential, increasing the amount of water vapor available to the atmosphere.

That additional atmospheric moisture can feed powerful atmospheric rivers—long, narrow corridors transporting enormous quantities of water vapor.

When these systems encounter mountain ranges, the consequences can become extreme.

Instead of falling as snow, warm atmospheric rivers can produce rain at elevations that historically received substantial snowfall. This creates a particularly dangerous combination: rain-on-snow events occurring simultaneously with already accelerated glacier and snowpack melt.

4. The Hydro-Thermal Double Whammy

Rain falling on snow and ice does more than add water.

Rain transfers sensible and latent heat directly into the snowpack and glacier surface. At the same time, the enormous volume of rainfall can rapidly increase runoff.

The result is a hydro-thermal double whammy:

Heat accelerates melting while water accelerates runoff.

Mountain drainage systems can become overwhelmed as rainfall, snowmelt, and glacier melt converge. Steep terrain magnifies the response, sending water and sediment rapidly into narrow valleys.

If landslides or debris flows block those valleys, temporary lakes can form behind natural dams of rock, ice, and sediment. Such impounded water can subsequently breach the blockage, generating devastating downstream floods, including glacial lake outburst floods (GLOFs).

The hazard therefore moves through the system:

Heat → glacier melt → permafrost thaw → slope failure → debris flow → river blockage → temporary lake → sudden flood.

One climate disturbance can become a cascade of physical disturbances.

The Compounding Cycle of Mountain Hazards

Climate Driver	Direct Physical Change	Resulting Environmental Hazard
Record Ambient Heat	Extreme high-elevation temperatures accelerate surface melting and weaken glacier structures.	Rapid ice loss, glacier destabilization, and structural collapse.
Permafrost Thaw	Ice binding rock and soil begins to melt, weakening the mountain’s internal structure.	Whole-slope failures, massive rockfalls, and debris-laden mudslides.
El Niño–Driven Moisture	Warmer oceans increase evaporation and atmospheric moisture availability.	More powerful atmospheric rivers and extreme precipitation events.
Rain-on-Snow Events	Warm rainfall adds heat and water directly to mountain snow and ice.	Accelerated melt, rapid runoff, flooding, and landslides.
Cascading Hydrology	Landslide and debris-flow material blocks narrow river channels.	Temporary lakes and potentially catastrophic glacial lake outburst floods.

Tipping Point Season

The most important signal may therefore not be the disappearance of an individual glacier.

It may be the increasing synchronization of multiple mountain processes.

Glacier loss changes surface reflectivity and water storage. Permafrost thaw weakens mountain slopes. Extreme heat raises the elevation of the melt zone. Atmospheric rivers deliver greater quantities of warm precipitation. Rain-on-snow events accelerate runoff. Landslides alter river channels. Temporary lakes form behind unstable debris dams. Those lakes can subsequently fail.

Each process can amplify another.

This is what makes mountain glacier loss a potential tipping-point problem. The danger is not necessarily one dramatic threshold at which a glacier suddenly disappears. The danger is a system in which multiple thresholds are approached simultaneously, feedbacks proliferate, interactions strengthen, and individual disturbances begin producing consequences far beyond their original location.

The mountain system becomes increasingly nonlinear.

A glacier that once functioned primarily as a frozen reservoir can become a source of floodwater. Permafrost that once stabilized a mountain slope can become a liability when it thaws. Snow that once stored water safely through the winter can become a mechanism for rapid runoff when warm rain falls on it. A landslide that once would have been a localized geological event can block an entire river and create a secondary flood disaster.

The result is a shift from ice loss to system instability.

That may be the larger lesson of Tipping Point Season: climate change is not simply making glaciers smaller. It is changing the physical relationships among ice, rock, water, atmosphere, and gravity.

And when those relationships begin changing together, the mountain can stop behaving like the mountain we knew.

How Coupled Climate Feedbacks Are Accelerating Earth-System Change

By Daniel Brouse

Simplified Introduction to:

🌎 TIPPING POINT SEASON

Tipping points are not necessarily isolated events waiting to happen one at a time.

Several have already begun moving together.

Ice loss changes albedo. Arctic warming alters atmospheric circulation. Greenland melt adds freshwater to the North Atlantic. Permafrost thaws and releases greenhouse gases. Forests are stressed by heat, drought, and fire. Ocean and atmospheric systems respond.

The important question is no longer simply: When will a tipping point occur?

It is: What happens when multiple tipping elements begin interacting with one another?

Tipping points come together. Feedbacks proliferate. Interactions strengthen. And acceleration emerges.

The climate system begins to change faster and in more complex ways than its individual pieces can be understood in isolation.

That is the idea behind the paper:

Tipping Point Season: Comingling Tipping Points and Proliferating Feedbacks

How Coupled Climate Feedbacks Are Accelerating Earth-System Change

The greatest danger may not be one tipping point suddenly toppling.

It may be several moving together.

🌡️ 1.5°C is not a magical switch.

It is a tripwire into a climate system where more interconnected components are being pushed toward critical states.

Tipping Point Season has begun.

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Comingling Tipping Points

The climate system has entered a new phase. The significance of the first sustained period in which global temperatures repeatedly exceeded 1.5°C above the pre-industrial baseline during 2023–2024 is not simply the number itself, but what is happening around that number. Across the planet, multiple components of the Earth system are simultaneously experiencing unprecedented or rapidly intensifying stress. Polar ice is disappearing, Arctic amplification is accelerating, permafrost is thawing, ocean heat content continues to rise, extreme marine heatwaves are becoming more consequential, and tropical forests are being stressed by increasing heat and drought. These are not isolated phenomena. They are interacting.

The central climate question is therefore changing. It is no longer sufficient to ask when an individual tipping point will be crossed. We must ask whether multiple tipping elements are already beginning to influence one another strongly enough to create a self-reinforcing cascade. The evidence increasingly indicates that they are. This is the comingling tipping points: a condition in which multiple vulnerable Earth-system components are changing simultaneously, altering the boundary conditions experienced by other components and strengthening feedbacks between them. The result is feedback proliferation. One change creates another, that change alters another part of the system, and the resulting response feeds back into the original disturbance. The climate system begins to behave less like a collection of separate components and more like a tightly coupled network. As coupling increases, the rate of change can increase with it.

1.5°C Is Not a Switch. It Is a Tripwire.

The 1.5°C threshold should not be imagined as a magical switch that suddenly activates every climate feedback. Climate feedbacks have always existed. What changes as warming increases is their strength, frequency, geographic extent, persistence, and interaction with other feedbacks. At approximately 1.5°C of global warming, numerous tipping elements become increasingly vulnerable, including Greenland ice-sheet instability, West Antarctic ice-sheet instability, Arctic sea-ice loss, permafrost thaw, boreal forest degradation, Amazon rainforest degradation, AMOC weakening, coral-reef collapse, and mountain-glacier loss.

These systems are connected through the atmosphere, oceans, cryosphere, biosphere, and hydrological cycle, and that connectivity matters. A warmer Arctic changes atmospheric temperature gradients; changing gradients alter circulation; circulation changes precipitation, drought, storm tracks, and heat transport; those changes affect forests, soils, glaciers, snowpack, and oceans. Ice loss changes albedo and freshwater delivery, while freshwater changes ocean density and circulation. Forest degradation changes carbon uptake and atmospheric moisture recycling, while permafrost thaw releases additional greenhouse gases. Each response changes the conditions under which the others operate. This is not theoretical coupling. It is the physical architecture of the climate system.

The El Niño Accelerator

ENSO provides another mechanism by which an already-warmed climate system can experience rapid additional warming. During El Niño, heat stored in the tropical Pacific is redistributed toward the atmosphere and higher latitudes, producing a temporary but potentially enormous pulse of global surface warming. A major 2026–2027 El Niño would therefore not be occurring in the climate system of the twentieth century; it would be occurring on top of a much warmer baseline.

That distinction is crucial because the same El Niño forcing applied to a cooler climate and a highly warmed climate does not necessarily produce the same system response. Background conditions have changed, and a strong El Niño can push global temperatures substantially above the 1.5°C level and potentially toward or beyond 1.6°C for extended periods. The danger is not that El Niño creates anthropogenic warming. Rather, an exceptionally warm baseline combined with a powerful natural climate oscillation can push already-stressed tipping elements closer to critical states simultaneously. A climate pulse can therefore become a trigger.

From Individual Tipping Points to Comingling Tipping Points

Consider the sequence already emerging across the polar climate system: polar amplification → weakened equator-to-pole temperature gradient → altered atmospheric circulation → accelerated Arctic and Greenland ice loss. That initial sequence immediately activates multiple feedbacks.

The ice–albedo feedback begins when ice loss exposes darker ocean and land surfaces. Those surfaces absorb more solar energy, producing additional regional warming and further ice loss: ice loss → darker ocean and land surfaces → greater solar absorption → additional warming → additional ice loss ↺. The Arctic consequently changes from a highly reflective surface toward a darker, increasingly heat-absorbing system.

At the same time, a melt–elevation feedback can develop as an ice sheet loses mass and elevation. Lower ice-sheet surfaces are exposed to warmer atmospheric conditions, increasing surface melting and producing further elevation loss: ice loss → lower ice-sheet elevation → exposure to warmer air → increased surface melting → additional elevation loss ↺. Arctic warming also alters the vertical temperature structure of the lower atmosphere, contributing to a lapse-rate feedback in which changes in the vertical temperature gradient can reduce atmospheric cooling efficiency near the surface and promote additional warming: Arctic warming → altered lapse rate → reduced atmospheric cooling efficiency near the surface → additional near-surface warming → additional ice and snow loss ↺.

These are not three independent feedbacks operating in isolation. They interact. The resulting cryospheric response can then connect to the ocean through accelerated Greenland melt and increased freshwater input into the North Atlantic. Freshwater can reduce salinity and density, contributing to AMOC weakening. Ocean circulation then connects back to the atmosphere through altered North Atlantic heat transport, pressure fields, and storm tracks. Atmospheric circulation can consequently reorganize, increasing jet-stream waviness and creating conditions favorable to persistent blocking.

The resulting sequence can extend into slower-moving Rossby waves, persistent blocking and omega blocks, prolonged heat domes, drought, stalled atmospheric rivers, and extreme precipitation. The consequence is hydroclimatic whiplash, in which the same atmospheric circulation regime can produce drought in one region and catastrophic flooding in another, sometimes in rapid succession. The components are no longer simply responding independently to global warming; they are modifying one another’s operating environment.

Feedback Proliferation

Once multiple tipping elements become coupled, the number of potential feedback pathways increases dramatically. A single change can propagate through several systems simultaneously. Consider the sequence: polar amplification → atmospheric circulation change → ice loss → albedo reduction → additional warming → Greenland melt → freshwater input → ocean circulation disruption → atmospheric circulation change → precipitation redistribution → drought and flood extremes → ecosystem stress → carbon-cycle disruption → additional greenhouse forcing → additional warming.

Now introduce permafrost. Warming → permafrost thaw → microbial decomposition → CO₂ + CH₄ release → additional greenhouse forcing → additional warming ↺. Add boreal forests: warming + drought + wildfire → forest degradation → reduced carbon uptake + carbon release → additional warming ↺. Add the Amazon: warming + drought + fire → reduced evapotranspiration → disrupted rainfall recycling → greater drought stress → forest degradation → carbon release → additional warming ↺. Add Antarctica: ocean warming → ice-shelf weakening → accelerated West Antarctic ice loss → sea-level rise → coastal and cryospheric stress.

The system is now operating as a network of interacting positive feedbacks. This is why the phrase feedback proliferation is more useful than simply listing individual feedbacks. The critical issue is not the existence of one feedback, but the rapidly expanding number of ways in which feedbacks can connect.

The Feedbacks Are Accelerating

Acceleration is particularly important because a climate system experiencing a given external forcing does not necessarily produce a constant rate of response. If feedbacks strengthen as warming increases, the response itself can accelerate. This creates a fundamental distinction between a linear response—forcing → proportional response—and a coupled nonlinear response in which forcing → response → feedback → stronger response → stronger feedback → acceleration.

This acceleration is increasingly visible in observations. Ocean heat has accumulated to extraordinary levels, marine heatwaves are becoming more intense and persistent, Arctic warming is occurring at multiple times the global average rate, Greenland is losing ice mass, Antarctica is losing ice mass, permafrost is thawing, extreme precipitation is intensifying as a warmer atmosphere carries more moisture, heat extremes are becoming more severe, and drought and wildfire are degrading major carbon-storing ecosystems.

These are not simply independent records of a warming planet. They are evidence of a planet whose internal responses are becoming increasingly consequential. The critical observation is not merely that each indicator is changing, but that multiple indicators are changing simultaneously across interconnected subsystems, with some changes occurring at accelerating rates. That is a signature of a system becoming increasingly nonlinear.

Water Vapor: The Fastest Amplifier

The water-vapor feedback demonstrates how rapidly a positive feedback can operate. Water vapor is the most abundant greenhouse gas in Earth’s atmosphere and provides one of the strongest and fastest positive feedbacks in the climate system. The Clausius–Clapeyron relationship indicates that the atmosphere can hold approximately 7% more water vapor for every 1°C of warming, assuming relative humidity remains broadly similar.

The sequence is straightforward: warming → increased atmospheric moisture → stronger greenhouse trapping → additional warming ↺. Water vapor does not provide the original forcing; it amplifies it. This feedback operates rapidly, on timescales ranging from days to weeks, and affects the entire atmospheric system. A warmer atmosphere also means that when moisture is transported into storm systems, more water can potentially be released as extreme precipitation. The same thermodynamic process that increases atmospheric heat retention can therefore contribute to more intense precipitation extremes, allowing one feedback to influence multiple hazards.

Ice–Albedo: The Arctic Heat Engine

The cryosphere provides another rapidly reinforcing feedback. Snow and ice reflect incoming solar radiation, while dark ocean and land surfaces absorb it. As Arctic ice disappears, the sequence becomes ice loss → reduced albedo → increased solar absorption → regional warming → additional ice loss ↺.

The Arctic is therefore not simply responding to global warming; it is increasingly participating in the amplification of regional warming. This is particularly important because Arctic amplification alters the temperature contrast between the poles and lower latitudes. That contrast is one of the fundamental drivers of atmospheric circulation, meaning that changes in the polar temperature structure can propagate outward into the mid-latitude atmosphere. The feedback does not stop at the Arctic. It travels.

Permafrost: The Carbon Feedback

Permafrost represents a slower but potentially persistent feedback. Frozen northern soils contain enormous quantities of organic carbon accumulated over thousands of years. When those soils thaw, microorganisms gain access to previously frozen organic matter. Depending on environmental conditions, decomposition releases carbon dioxide and methane.

The sequence is therefore warming → thaw → decomposition → greenhouse-gas release → additional warming ↺. Unlike water vapor, this feedback can continue long after the initial warming event, making it a potential bridge between short-term climate acceleration and long-term carbon-cycle destabilization.

Boreal Forests: From Carbon Sink to Carbon Stress

Boreal forests are increasingly exposed to compound stress from heat, drought, insects, disease, and wildfire, with these stresses capable of interacting rather than simply occurring independently. A forest weakened by drought becomes more vulnerable to fire, fire releases stored carbon, and the loss of forest cover reduces future carbon uptake. The resulting feedback is warming → drought + fire → forest degradation → reduced carbon uptake + carbon release → additional atmospheric warming ↺.

The significance lies in the possibility of a transition from a carbon-absorbing ecosystem toward one that increasingly contributes carbon to the atmosphere. That transition would not be instantaneous, nor would it occur uniformly across the boreal zone, but the direction of the feedback is clear: increasing climate stress can progressively weaken an important carbon sink.

Amazon: The Rainfall-Recycling Feedback

The Amazon provides an even more tightly coupled example because the forest does not merely receive rainfall; it helps generate and recycle it. Through evapotranspiration, vegetation transfers enormous quantities of water back into the atmosphere. Repeated drought and heat stress can weaken this mechanism, creating a potentially dangerous feedback: warming → drought → forest stress → reduced evapotranspiration → reduced rainfall recycling → greater drought → forest degradation → carbon release ↺.

The forest therefore becomes both a victim and a participant in the warming process. The more the ecosystem is degraded, the more its ability to sustain the hydrological processes on which it depends can be compromised, while the carbon released through degradation and fire can add further greenhouse forcing.

The Comingling Cascade

When these systems are considered together, the emerging picture is fundamentally different from a simple list of tipping points. It can be represented as a connected cascade:

POLAR AMPLIFICATION → ARCTIC ICE LOSS → ICE–ALBEDO AMPLIFICATION → GREENLAND ICE LOSS → FRESHWATER INPUT → AMOC STRESS → ATMOSPHERIC CIRCULATION REORGANIZATION → JET-STREAM WAVINESS + PERSISTENT BLOCKING → HEAT DOMES + DROUGHT + STALLED ATMOSPHERIC RIVERS → HYDROCLIMATIC WHIPLASH → AGRICULTURAL + INFRASTRUCTURE + ECOSYSTEM + PUBLIC-HEALTH STRESS → PERMAFROST THAW → CO₂ + CH₄ RELEASE → ADDITIONAL GREENHOUSE FORCING → BOREAL FOREST DEGRADATION → CARBON LOSS + WILDFIRE → AMAZON DROUGHT + FOREST DEGRADATION → ADDITIONAL CARBON RELEASE → ADDITIONAL WARMING → FEEDBACK INTO THE ENTIRE SYSTEM.

This is no longer adequately described as a series of isolated tipping points. It is a tipping cascade, and the cascade is capable of feeding back into itself.

The Speed of the System Is Changing

This may be the most important implication. The climate system is not simply moving toward a warmer equilibrium; it is increasingly exhibiting faster transitions between states. Heat accumulates, ice responds, water vapor amplifies, atmospheric circulation reorganizes, extreme precipitation intensifies, drought stresses ecosystems, wildfire releases carbon, permafrost thaws, and ocean circulation responds. Each process operates on a different timescale, but those timescales overlap, and that overlap creates opportunities for comingling.

A slow process such as ice-sheet destabilization can interact with a faster process such as atmospheric circulation. A seasonal event such as El Niño can temporarily push a slower-moving tipping element toward a threshold. A wildfire can rapidly convert a carbon sink into a carbon source, while a marine heatwave can stress an ecosystem already weakened by long-term warming. The climate system therefore contains multiple clocks, and as warming increases, those clocks increasingly begin to interact.

A New Way of Thinking About 1.5°C

The importance of 1.5°C is therefore not that crossing it suddenly turns the climate system into something entirely different. Its importance is that it places an increasing number of interconnected systems into a zone of elevated vulnerability. The relevant question is not simply whether we crossed 1.5°C, but how many systems are now being pushed toward critical states, how strongly those systems are interacting, whether their feedbacks are strengthening, and whether the rate of change is increasing.

Most importantly, we must ask whether we are beginning to see the Earth system respond to itself.

There is growing evidence that the answer is yes. Human emissions remain the primary driver of contemporary global warming, but the climate system does not remain passive after that forcing occurs. It responds. That response creates feedback. Feedback creates amplification. Amplification changes the conditions experienced by other systems. Those systems respond, and their responses feed back again.

That is the central danger of comingling tipping points.

From Tipping Points to Tipping Point Season

The old conceptual model was relatively simple: human emissions → warming → impacts. The emerging model is more complicated: human emissions → warming → tipping-element stress → feedback activation → system interaction → amplification → additional warming and disruption → additional feedback activation.

The Earth system is becoming an active participant in the trajectory we have initiated. This does not mean that climate change has become independent of human emissions. It means that the consequences of those emissions are increasingly being amplified by the physical and biological systems they have destabilized.

That is why the distinction between climate forcing and climate response is becoming increasingly important. We are no longer dealing solely with the question of how much additional warming humans will cause. We must also contend with how much additional change the warming already imposed can generate through Earth-system feedbacks.

That is the beginning of Tipping Point Season: not a season defined by one spectacular threshold, but a season defined by comingling—multiple tipping elements, multiple feedbacks, multiple timescales, multiple cascading pathways, and an increasingly observable acceleration in the response of the Earth system.

The greatest danger may therefore not be that one tipping point suddenly topples, but that several have already begun moving together. Tipping points are beginning to come together, feedbacks are proliferating, interactions are strengthening, and acceleration is emerging across interconnected Earth-system components. The climate system is consequently beginning to change faster and in more complex ways than its individual pieces can be understood in isolation.

That is the climate challenge we now face: not simply tipping points, not simply feedbacks, but tipping points comingling and feedbacks accelerating one another.

by Daniel Brouse

Introduction: What Is Tipping Point Season?

The first tipping point season was 2023–2024, when global temperatures exceeded +1.5°C for an extended period. During that season, nine tipping points became observable:

• Greenland Ice Sheet Collapse
• West Antarctic Ice Sheet Collapse
• Labrador–Irminger Seas/SPG Convection Collapse
• East Antarctic Subglacial Basins Collapse
• Arctic Winter Sea Ice Collapse
• East Antarctic Ice Sheet Collapse
• Amazon Rainforest Dieback
• Boreal Permafrost Collapse
• Atlantic Meridional Overturning Circulation (AMOC) Collapse

This phenomenon occurred simultaneously with El Niño. ENSO is not a cause of climate change; rather, it is a manifestation of the climate system’s accumulated energy. Most of that accumulated climate energy is stored in the oceans. Every several years, much of this heat is brought toward the surface in an oscillating pattern.

Over the last 30 years, El Niño events have continued to occur at their historical frequency of roughly every 2 to 7 years, but their intensity has dramatically increased. A recent August 2026 study by the University of Michigan revealed that El Niño events have become nearly 40% stronger over the last few decades compared with the pre-industrial era.

The last 30 years have borne witness to three of the most powerful “Super El Niño” events in recorded history, alongside an exceptionally strong event currently unfolding in 2026. The extreme heat released by this “supersized” El Niño is expected to temporarily push the entire planet above the 1.5°C global warming limit by late 2026 and into 2027.

A Planetary Feedback Network

This tipping point season is pushing the climate system even further, with traditionally non-connected tipping points and feedbacks beginning to couple with one another. One example is the coupling of a Pacific El Niño and an 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. 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.

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

became: 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.

This tipping point season makes observable, for the first time in history, the coupling, interaction, and amplification of feedbacks—and their collective pushing of tipping points into their second derivation.

When Climate Feedbacks Stop Looking Theoretical

By Daniel Brouse

The 2023–2024 El Niño event made observable what had previously been discussed largely as theoretical: multiple climate-system tipping processes were being pushed simultaneously.

At least nine potential tipping points were being knocked or pushed toward critical thresholds during the 2023–2024 period. Two of the clearest examples were global coral reef degradation and accelerating permafrost instability.

What has happened since is even more significant.

The 2026–2027 El Niño is now developing on an Earth system that is already substantially warmer and more stressed than it was during the previous major El Niño. NOAA reported in August 2026 that El Niño was strengthening, with a greater than 90% probability of a very strong event during the Northern Hemisphere fall and winter of 2026–27. NOAA also estimated a 69% probability that October–December 2026 would produce a historic event exceeding +2.5°C in the three-month Relative Oceanic Niño Index—a level exceeding previous El Niño events dating back to 1950.

This matters because tipping behavior does not occur in isolation.

A system that has already been weakened can respond very differently to the next pulse of heat.

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The 2023–2025 Coral Reef Collapse

The massive global coral bleaching event that began in 2023 and extended through 2025 was not simply another bad year for coral.

NOAA confirmed in April 2024 that the world was experiencing its fourth global coral bleaching event on record, and the second in only ten years. By the time NOAA’s assessment was updated in 2026, bleaching-level heat stress had affected approximately 84.4% of the world’s coral reef area, with mass bleaching documented across at least 83 countries and territories. NOAA characterized it as the largest global bleaching event on record.

The significance is not merely the percentage of reefs exposed to heat.

Coral reefs depend upon a narrow thermal range. Extreme heat disrupts the relationship between coral animals and the symbiotic algae that supply much of their energy. Bleaching therefore represents a fundamental physiological failure, not simply a change in color.

When extreme heat persists, bleaching can progress to starvation, disease and mortality. And recovery requires time. That is where the feedback becomes dangerous.

If reefs are repeatedly exposed to severe marine heatwaves before they have recovered, the system can move from temporary disturbance to structural ecological degradation. A reef that loses living coral loses the biological architecture that supports fish, coastal protection, biodiversity and future coral recruitment.

The recovery window is shrinking.

A 2026 assessment by the Global Coral Reef Monitoring Network found that the average interval between mass bleaching events has fallen to roughly five or six years, while coral cover during 2020–2024 was approximately 9.5% below historical averages. The 2023 event alone affected an estimated 77% of global reef area, according to the assessment.

The crucial point is that the next El Niño does not begin with the coral system restored to its previous condition.

It begins with an already damaged system.

And now the Pacific is heating again.

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The 2026–2027 El Niño

The present El Niño is not hypothetical.

NOAA reported in August 2026 that sea-surface-temperature anomalies in the eastern equatorial Pacific had exceeded +2°C, while subsurface temperature anomalies reached approximately +10°C at depth. The agency reported a greater than 90% probability of a very strong El Niño during the 2026–27 Northern Hemisphere fall and winter.

By August, sea-surface temperatures in parts of the eastern equatorial Pacific were near or above +3°C, with a Niño-3.4 weekly index around +1.8°C.

This is precisely why the timing matters.

The planet is not resetting between El Niño events.

Heat accumulates in the climate system. Oceans retain enormous quantities of that energy. Ice sheets lose mass. Permafrost thaws. Forests burn. Coral reefs experience repeated thermal stress. Ecosystems lose resilience.

The next disturbance therefore acts upon a system already pushed closer to its limits.

That is how tipping behavior becomes possible.

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Permafrost: The Other Domino

The same basic principle applies to permafrost.

Permafrost is not simply frozen dirt.

It is a massive reservoir of organic carbon accumulated over thousands of years. When frozen ground thaws, microbes gain access to previously locked organic material. They decompose it and release carbon dioxide and, under oxygen-poor conditions, methane.

That creates a feedback:

warming → thaw → microbial decomposition → greenhouse-gas emissions → additional warming → additional thaw.

But that is only one part of the process.

Permafrost is also physically coupled to vegetation, soil moisture, hydrology, fire, snow cover and ground ice.

Once those connections begin changing rapidly, the response can become nonlinear.

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The “Compost Bomb” Effect

One of the most striking mechanisms is what can be called the “compost bomb” or self-heating effect.

When previously frozen organic matter thaws, microbial decomposition accelerates. Decomposition is an exothermic process: biological activity releases heat. That heat is not large enough to explain Arctic warming by itself, but locally it can become part of a reinforcing thermal environment.

That warming activates biological processes that themselves produce heat and greenhouse gases inside a system already undergoing thermal destabilization.

The frozen carbon reservoir is effectively being converted from a long-term carbon store into an active component of the carbon cycle.

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Water Carries the Heat

Rain and changing hydrology provide another pathway.

Permafrost responds not only to air temperature but to the movement of heat through the ground.

Warm rain can penetrate the active layer and transport heat downward. Changes in snow, soil moisture, drainage and groundwater can alter how efficiently heat is stored and transferred through frozen ground.

The result is a system in which atmospheric warming, precipitation, hydrology and ground temperature interact.

This is particularly important because the response is not necessarily gradual.

Research on abrupt permafrost thaw has shown that collapsing ground, rapid erosion, landslides and thermokarst can expose large quantities of previously protected carbon much faster than gradual thaw models assume. Abrupt thaw may occur across less than 20% of the permafrost zone yet potentially affect roughly half of its stored permafrost carbon.

That is a tipping mechanism.

Not because every square mile of permafrost suddenly disappears, but because a relatively limited area of abrupt thaw can have a disproportionately large effect on the carbon cycle.

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Thermokarst: When Frozen Ground Loses Its Structure

Permafrost is also a structural system. Ice binds soil and sediment together. When that ice melts, the ground can collapse.

The result is thermokarst—a landscape of subsidence, ponds, lakes, gullies and collapsing terrain.

This can expose deeper layers of ancient carbon, including carbon-rich deposits such as Yedoma, to oxygen, microbes, water and atmospheric processes.

The important distinction is between gradual thaw and abrupt thaw.

Gradual thaw progressively deepens the seasonally thawed active layer. Abrupt thaw can physically destroy the ground.

That difference matters enormously.

Once the ground collapses, hydrology changes. Lakes form or drain. Slopes destabilize. Sediment moves. Previously protected organic material becomes exposed.

The carbon cycle has effectively changed gears.

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Fire Removes the Insulating Blanket

Then there is fire.

The extraordinary Canadian and Siberian wildfires of recent years are not merely consequences of Arctic warming. They can also become mechanisms that accelerate permafrost degradation.

The surface vegetation, moss and peat layer acts as an insulating blanket. Fire removes that blanket. The exposed soil can absorb substantially more solar energy, increasing ground temperatures and deepening the active layer.

The effect can persist for decades.

Research in Canadian permafrost peatlands has found that wildfire impacts on the soil thermal regime can persist for approximately 30 years, with burned areas experiencing warmer and deeper active layers and accelerated thermokarst development.

The relationship works in both directions.

Warming promotes fire.

Fire promotes permafrost thaw.

Thaw can promote soil drying and further fire.

Recent modeling research published in Nature Communications found that rapid permafrost thaw can produce abrupt changes in soil hydrology, surface warming and atmospheric dryness that intensify Arctic and sub-Arctic wildfires, particularly in western Siberia and Canada.

This is not a single feedback loop.

It is a network of feedback loops.

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The Zombie-Fire Connection

The most disturbing manifestation is the phenomenon popularly called the “zombie fire.”

Peat and organic soils can continue smoldering beneath the surface after the visible flames disappear. These fires can survive through winter and re-emerge when conditions become favorable.

That means a previous year’s fire can effectively become the seed for the next year’s fire. The system acquires memory.

And that matters because climate tipping behavior often involves precisely this kind of persistence: the system does not return to its previous state when the original disturbance ends.

The fire changes the ground. The changed ground changes the next fire. The next fire changes the ground again.

Meanwhile, the carbon released by both combustion and thaw adds additional greenhouse gases to the atmosphere.

The 2023 Canadian fire season demonstrated the scale of this problem. A Nature study estimated approximately 647 million tonnes of carbon (647 TgC) were emitted by Canadian fires from May through September 2023—comparable to the annual fossil-fuel carbon emissions of a major industrial nation. The burned area was more than seven times the average annual area of the preceding four decades.

The climate system is therefore not merely warming the Arctic.

It is increasingly capable of removing the mechanisms that kept the Arctic frozen.

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Then Came Nepal and Tibet

And this brings us to the next level of the argument.

On August 26, 2026, a massive collapse occurred in the Nepal–Tibet border region.

A glacier and associated rock mass collapsed from approximately 5,200 meters, sending ice, rock, sediment and water cascading more than 1,200 meters into the valley below. The resulting event produced a catastrophic flash flood through the Bhotekoshi and Trishuli river systems.

The scale was extraordinary.

By September 3, more than 1,200 people had been reported dead in Nepal, thousands remained missing, entire communities had been destroyed, and thousands of homes had been destroyed or rendered uninhabitable.

It might be premature to claim that the 2026 El Niño directly caused the Nepal–Tibet collapse. The scientific investigation is still developing. But that does not make the event irrelevant to tipping-point dynamics.

Quite the opposite.

It demonstrates what happens when multiple components of a cryospheric system become unstable simultaneously.

Glacier.

Rock.

Water.

Permafrost.

Slope stability.

River system.

Infrastructure.

One failure can trigger another.

That is the essence of a tipping cascade.

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The Second Derivative of the Problem

The August 26, 2026 Nepal–Tibet event was something more than simply another climate disaster.

The first derivative is change. The second derivative is acceleration of change.

But there is another level beyond acceleration:

the coupling of changes.

A glacier loses mass. Permafrost warms. Ground ice melts. Water penetrates fractures. The frozen material that once helped bind rock and soil together loses strength. Slopes become unstable. Rock loses support. Glacial ice moves. A glacier, rock mass, or entire mountainside collapses. The collapse mobilizes ice, water, sediment and debris. The resulting torrent can destroy roads, bridges, vehicles, homes and entire sections of river valleys.

One destabilized component triggers another.

That is a tipping cascade.

And this is precisely why treating every tipping point as an isolated phenomenon misses the larger danger.

Permafrost Is the Glue

Following the catastrophic August 26, 2026 bedrock failure and glacier collapse along the Nepal–Tibet border near Langtang Lirung, geomorphologists have increasingly scrutinized the role of high-altitude permafrost in mountain stability.

In high-altitude alpine environments such as the Himalayas, permafrost is not merely frozen soil. It can function as a critical structural component of the mountain itself.

Ice within fractures, rock pores and sediment acts as a natural cement. Frozen ground can increase the mechanical strength of slopes and help stabilize otherwise extremely steep terrain. When that ground warms and the ice melts, the mechanical properties of the mountain change.

The mountain does not simply become warmer.

It becomes structurally weaker.

That distinction is fundamental.

For thousands of years, freezing temperatures helped lock together rock, sediment, ice and soil. Climate warming attacks that system from multiple directions simultaneously. Higher air temperatures warm the ground. Changing snow cover alters the insulation of the surface. Meltwater and rainfall can penetrate fractures. Repeated freeze–thaw cycles weaken rock. And as permafrost ice melts, the frozen bonds that previously helped hold the landscape together disappear.

The result can be progressive destabilization followed by abrupt failure.

This creates a particularly dangerous feedback:

warming → permafrost thaw → loss of structural strength → slope instability → collapse → debris and water mobilization → downstream destruction.

And the process does not necessarily stop at the first collapse. A collapsing glacier can destabilize rock. A rock avalanche can displace enormous quantities of water. Water can erode and destabilize additional slopes. Sediment can transform a river into a rapidly moving debris flow. The debris flow can destroy infrastructure and alter the river channel. A newly formed blockage can create a temporary lake that becomes another hazard when it fails.

In other words, the mountain itself can become a chain reaction.

The Permafrost Connection

This is where the Nepal–Tibet event becomes particularly important to the broader tipping-point argument.

Permafrost is one of the hidden components of the cryosphere. Unlike a retreating glacier, its destabilization is often invisible until the physical structure it supports begins to fail.

You may not see permafrost disappearing. You see what happens after it disappears. You see rockfalls. You see landslides. You see collapsing slopes. You see thermokarst. You see rivers suddenly carrying enormous quantities of sediment. And, in extreme cases, you see entire mountainsides transform from solid terrain into a rapidly moving mixture of rock, ice, water and soil.

That is why the Nepal–Tibet collapse can be viewed as a possible second-order manifestation of cryospheric destabilization.

The first-order effect is warming. The next effect is permafrost degradation. The next is loss of structural integrity. Then comes cascading physical failure. The climate signal has effectively been converted into mechanical energy.

Frozen ground becomes unstable ground.

Stable ground becomes a landslide.

A glacier becomes a flood.

A mountainside becomes a river of debris.

That is what makes tipping cascades so different from ordinary linear climate change. The danger is not simply that each component changes. The danger is that the components are connected. Permafrost can be the glue holding the system together.

Remove the glue, and the pieces do not merely move independently.

They can bring each other down.

This is the second derivative of the problem:

not merely that the climate is changing, and not merely that the rate of change is accelerating, but that increasingly unstable components are beginning to interact in ways that amplify one another.

And when those interactions become visible as collapsing mountains, cascading glaciers, flash floods and debris flows, the tipping point is no longer something we have to imagine.

You can watch it happen.

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Climate Energy Becomes Fluidized

There is something visually profound about events like this. Climate energy is normally discussed in abstract units: joules, watts per square meter, degrees Celsius. But once enough energy accumulates in the Earth system, its consequences become physical.

Ice melts.

Rock fractures.

Slopes collapse.

Water accelerates.

Sediment becomes a moving fluid.

Rivers jump their banks.

Roads disappear.

Bridges are ripped from their foundations.

Cars, homes, trees and entire sections of mountains can become part of a single moving mass.

You can literally watch stored climate energy being converted into motion.

That is the part that makes these events so difficult to dismiss as theoretical.

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From the Arctic to Pennsylvania

The connection is not confined to the Arctic.

When smoke from the Canadian wildfires descended into Pennsylvania in both 2023 and 2026, the feedback was no longer an abstract Arctic phenomenon. It became observable from the ground. People who had never seen the Arctic could see the consequences of an increasingly unstable northern climate hundreds or thousands of miles away.

The smoke was a visible atmospheric connection between a rapidly changing high-latitude system and everyday life in the northeastern United States.

That is another characteristic of cascading climate disruption:

distance stops protecting us.

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The Dominoes Are Already Moving

This is ultimately “tipping points that toppled” means. A tipping point is often imagined as a single dramatic moment when a system suddenly crosses a line. Earth systems are rarely that simple. They are networks.

Coral reefs are connected to ocean temperature, marine heatwaves, disease, ocean chemistry and ecological recovery.

Permafrost is connected to air temperature, snow, vegetation, soil moisture, microbial activity, hydrology and fire.

Glaciers are connected to temperature, precipitation, meltwater, rock stability, permafrost and downstream hydrology.

These systems interact.

A destabilized system can therefore push another system toward instability.

That is the real danger.

The 2023–2025 coral bleaching catastrophe demonstrated how quickly a global ecosystem can be subjected to unprecedented simultaneous heat stress. The permafrost-fire relationship demonstrates how warming can activate feedbacks that reinforce the original warming. The 2026 Nepal–Tibet catastrophe demonstrates how instability within a cryospheric system can cascade through ice, rock, water and infrastructure.

And the 2026–2027 El Niño is now arriving on top of all of it.

NOAA’s current assessment gives this El Niño a greater than 90% probability of becoming very strong, with a substantial probability of reaching historic strength. We should therefore stop asking only:

“Has a tipping point been crossed?”

The more important question is:

“How many systems are already unstable enough that the next disturbance can push them into a new state?”

Because that is what tipping cascades look like. Not one domino. A row of them. And increasingly, we can watch them fall.

They are no longer merely theoretical.

They are observable.

They are physical.

And they are happening now.

by Daniel Brouse

Public Access Introduction

🌎 HOW IS CLIMATE ENERGY HITTING YOU?

🏊 Backyard Megapitfall Traps: A Changing Ecosystem for Frogs, Spiders & Worms

What can a swimming pool tell us about climate change?

More than you might think.

A backyard pool can unintentionally become a giant ecological trap—and an unexpected biological sensor.

🪱 Earthworms increase after extreme rainfall.

🐛 Millipedes emerge during flash droughts and extreme evaporation.

🕷️ Water-walking spiders are increasing, potentially responding to greater prey availability.

🐸 And the most striking change?

The frogs have disappeared.

What was once a regular cycle of frog rescues and deaths has declined to zero frogs in the pool.

That doesn’t mean a backyard pool can prove climate causation. But it can reveal something important: ecological change leaves fingerprints.

Heat. Drought. Extreme rainfall. Evaporation. Habitat stress. Changing food webs.

These forces don’t remain somewhere far away in a climate model. They reach the backyard.

🌡️ Climate energy → weather extremes → habitat changes → animal behavior → changing wildlife

The pool is small.

The creatures are small.

But the ecological signal may not be.

🔎 Sometimes the first signs of a changing planet are right in your own backyard.

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The Experiment

Backyard Megapitfall Traps: A Changing Ecosystem for Frogs, Spiders, and Worms

A swimming pool can unintentionally function as a giant megapitfall trap—an ecological trap that collects animals from the surrounding landscape. What falls into the pool, what survives, and what disappears can provide a surprisingly revealing snapshot of changes taking place in the local ecosystem.

Detection Surveys: Using Pools as Wildlife Traps

When scientists deliberately examine swimming pools to sample local wildlife or detect invasive species, the practice can be described as a swimming-pool detection survey. Because pools are already constructed, filled with water, and often surrounded by terrestrial habitat, they can serve as convenient passive sampling sites for studying urban and suburban biodiversity.

A backyard observation project in southeastern Pennsylvania has produced several striking changes over the past several years. Although a single backyard pool is not a controlled scientific experiment, the patterns are sufficiently noticeable to raise important questions about how changing temperature, precipitation, drought, and habitat conditions may be affecting local wildlife.

1. More Earthworms After Extreme Rainfall

Earthworms have become noticeably more common in the pool following intense rainfall events.

During heavy rain, saturated soils can force earthworms toward the surface. Flash flooding and rapid changes in soil moisture can then transport them across lawns and other surfaces, increasing the likelihood that they end up in the pool.

The connection to hydroclimatic whiplash—rapid swings between very wet and very dry conditions—is particularly interesting. Increasingly erratic precipitation can produce conditions in which soils cycle rapidly between saturation and drying, potentially altering earthworm movement and survival.

2. More Millipedes During Dry and Wet Extremes

Millipedes have also become more noticeable.

During dry periods, extreme evaporation and declining soil moisture can drive millipedes out of their preferred moist environments in search of shelter and water. When intense rainfall follows a period of drought, the resulting rapid change in soil conditions can further disrupt their normal movement patterns.

This combination of flash drought, extreme evaporation, and intense rainfall is another example of hydroclimatic whiplash affecting even the smallest components of the backyard ecosystem.

3. Water-Walking Spiders: An Unexpected Increase

Perhaps the most intriguing observation is not the number of dead spiders in the pool, but the increasing number of living, water-walking spiders.

Many terrestrial animals—voles, earthworms, beetles, and other insects—fall into the pool accidentally and eventually drown. Water-walking spiders are different. Their hydrophobic bodies and specialized legs allow them to exploit the water surface rather than simply becoming victims of the trap.

The pool can therefore function as an intentional hunting ground rather than an accidental death trap.

Surface tension provides the physical mechanism. The spider’s lightweight body and water-repellent structures allow it to distribute its weight across the water surface without breaking through. Rather than being trapped by the pool, these spiders can use it as habitat.

The noticeable increase in water-walking spiders may reflect several factors, including increased prey availability. This observation coincides with a noticeable increase in beetle activity and other potential food sources around the pool. However, despite the increase in beetle activity, there has not been a corresponding increase in beetle carcasses in the pool. One possible explanation is that the growing spider population is consuming more of the available prey before it accumulates as dead insects in the trap. While this remains a hypothesis, the simultaneous increase in spiders and apparent reduction in prey carcasses is an intriguing pattern worth further observation.

4. The Most Striking Change: Where Are the Frogs?

The most dramatic change in this backyard megapitfall record is the disappearance of frogs.

Frog rescues—and frog deaths—were once common occurrences. Over the past several years, however, the number has steadily declined until there have been zero frogs in the pool.

That does not, by itself, establish that climate change caused a local frog disappearance. But it is a striking observation because amphibians are among the world’s most threatened groups of vertebrates, and they are exceptionally sensitive to changes in temperature, moisture, disease, habitat, and water availability.

The disappearance of frogs from one backyard may therefore be worth viewing as a potential local ecological signal rather than simply an absence of frogs in a swimming pool.

Why Are Amphibians So Vulnerable?

Climate change can interact with multiple stresses that already affect amphibians. Four mechanisms are particularly important.

1. Loss and Drying of Breeding Ponds

Many frogs depend on temporary wetlands, vernal pools, shallow ponds, ditches, and other small bodies of water for reproduction.

Changes in precipitation, warmer temperatures, and increased evaporation can cause these habitats to dry earlier. If breeding pools disappear before tadpoles complete metamorphosis, an entire reproductive season can fail.

Repeated failures over several years can eventually eliminate a local population.

2. Terrestrial Dehydration

Frogs have highly permeable skin and depend on moist environments to maintain water balance.

During periods of extreme heat and drought, the landscape between a frog’s refuge and a backyard pool can become increasingly hostile. Hot lawns, dry soil, pavement, and other impervious surfaces can create barriers that frogs cannot safely cross.

Unlike a water-walking spider, a frog cannot simply tolerate prolonged exposure to a dry, overheated landscape.

3. Disease and Chytrid Fungus

Climate and weather can also interact with infectious disease.

Batrachochytrium dendrobatidis (Bd), commonly known as chytrid fungus, infects amphibian skin and has contributed to severe population declines and extinctions around the world.

The relationship between climate and chytrid disease is complex. Temperature and moisture conditions can influence pathogen growth, transmission, and host susceptibility. Climate change can therefore alter the geographic and seasonal conditions under which amphibian diseases spread.

4. Urbanization and Habitat Fragmentation

Climate stress does not occur in isolation.

Suburban development fragments forests, wetlands, and other amphibian habitat into increasingly isolated patches. A small local population may have nowhere to go when drought, extreme heat, disease, or another disturbance strikes.

Once a population disappears from an isolated habitat fragment, recolonization may be difficult or impossible.

A Backyard Window Into a Larger System

The swimming pool is not a climate instrument. It cannot tell us, by itself, why one species increases while another disappears.

But it can function as an unexpected biological sensor.

The pool collects organisms moving through the surrounding environment. Changes in what appears in the water—and what no longer appears—may reflect changes occurring beyond the pool itself.

Earthworms responding to extreme rainfall.

Millipedes responding to drying soils and sudden moisture.

Water-walking spiders exploiting a changing surface environment.

And frogs disappearing altogether.

These observations raise a larger question:

What happens when the energy entering the climate system is redistributed through the biological system?

Climate change does not arrive in our backyards as an abstract global average temperature. It arrives through altered rainfall, flash floods, drought, evaporation, heat, disease, habitat stress, and changing interactions among species.

Sometimes the evidence is visible in a satellite image.

Sometimes it is recorded by a weather station.

And sometimes, surprisingly, it is floating in your swimming pool.

Expert Perspective

The broader amphibian decline is well documented. The U.S. Geological Survey has reported substantial long-term declines in amphibian populations and has highlighted the vulnerability of amphibians to increasing heat and declining water availability.

One USGS analysis estimated an average annual decline in amphibian abundance of approximately 3.8% per year, with continued declines potentially causing species to disappear from large portions of their former ranges.

The lesson from the backyard pool is not that every ecological change can be pinned on climate change. The lesson is that ecological change leaves fingerprints—and sometimes those fingerprints appear in places we never thought to look.

What enters the trap matters. What survives matters. And what suddenly stops appearing may matter most of all.

The increase in earthworms following extreme rainfall, the surge of millipedes during swings between drought and deluge, the growing presence of water-walking spiders, and the disappearance of frogs are not isolated curiosities. Together, they form a changing biological pattern—a small, local record of a system under stress.

The backyard pool may therefore be more than a place where wildlife accidentally dies.

It may be a biological window into a changing climate.

A swimming pool is tiny compared with the planetary climate system. But climate change is not experienced as a planetary abstraction. It is expressed locally—in the soil, in the water, in insects and spiders, in amphibians, and in the species that suddenly become common or disappear altogether.

The megapitfall trap is small. The signal may not be.

What is happening in this backyard may be one tiny piece of a much larger planetary experiment—one that is already unfolding around us.