Tag: Ocean Circulation

Ancient Stalagmites Reveal When the Global Monsoon Breaks Its Seesaw

A new 450,000- year speleothem (stalagmite) record from the Peruvian Andes shows that the South American Summer Monsoon (SASM) and Asian monsoon were mostly out of phase (a “seesaw”), but occasionally synchronized, both strengthening or both weakening, especially during glacial terminations and warm intervals.

This research relates to climate change primarily by showing how the global monsoon system has responded to rapid shifts in planetary boundary conditions in the past, conditions that are analogous in some ways to those changing today.

Infographic titled 'Ancient Stalagmites Reveal When the Global Monsoon Breaks Its Seesaw' illustrating isotopic archives of rainfall, atmosphere, and climate connections, featuring a diagram of stalagmite layers, a world map highlighting South America and Asia, and details on monsoon patterns and growth rates over 120,000 years.
AI generated by Grok

A new 450,000- year speleothem (stalagmite) record from the Peruvian Andes shows that the South American Summer Monsoon (SASM) and Asian monsoon were mostly out of phase (a “seesaw”), but occasionally synchronized, both strengthening or both weakening, especially during glacial terminations and warm intervals.

The study, published in Nature as “Interhemispheric monsoon dynamics over the past 450,000 years” (Olson, E. J. et al., 2026), is based on oxygen -isotope (δ¹⁸O) data from Andean cave stalagmites (including sites such as Huagapo and Pacupahuain in the Junín region of the Amazon Basin and Andes).

These records track monsoon intensity via the “amount effect”, in which heavier rainfall produces lower δ¹⁸O values. Uranium -thorium dating provided precise ages. Researchers combined the cave data with a nearby Lake Junín glacial/sediment record to isolate a regional SASM signal from local effects.

Key findings

  • Dominant pattern (seesaw): For most of the past ~450,000 years (spanning multiple glacial–interglacial cycles), SASM and Asian monsoon strength varied in antiphase. When one strengthened, the other weakened. This matches Milankovitch orbital forcing (especially precession, ~21,000- year cycles), which shifts seasonal solar insolation between hemispheres and supports the idea of a coherent “global monsoon” system.⁠
  • Exceptions (synchrony): About ten intervals exceeded a synchronicity threshold (identified via running Pearson correlations and mean comparisons of the records). These include glacial terminations (abrupt ends of ice ages) and some warm interglacial and interstadial periods. Synchronous drying occurred during terminations and several warm intervals; synchronous wet conditions were rarer (mainly in the penultimate glacial, MIS 6). In these windows the monsoons moved together rather than opposing each other.⁠
  • Drivers of the exceptions: These events coincide with rapidly changing boundary conditions, rising greenhouse- gas levels, shifting cross- equatorial thermal gradients, anomalous Atlantic and Pacific sea- surface temperatures, ice- sheet collapse, and disruptions to ocean circulation (e.g., Atlantic Meridional Overturning Circulation). Model comparisons support links between high- latitude ocean changes and tropical rainfall reorganization.

Broader implications

The global monsoon system supplies freshwater to more than 2.7 billion people. The record shows it is not rigidly locked to orbital cycles alone; it can reorganize for millennia when ice sheets, greenhouse gases, and ocean temperatures change quickly.

Synchronous droughts across hemispheres would strain water availability on both sides of the equator. The findings provide a long- term natural experiment relevant to understanding monsoon responses under rapid modern forcing.⁠

Related coverage and summaries appear in Nature research briefings, Springer Nature Communities (“Behind the Paper”), Scienmag, and similar outlets; the primary paper is in Nature (doi: 10.1038/s41586-026-11166-3). Data are archived at NOAA NCEI.

Topographic map of a mountainous region in South America showing elevation changes, with a highlighted lake labeled 'd' and marked locations 'a', 'b', and 'c'. An inset map indicates the region's location within South America.
Location of caves where speleothems were recovered. Credit: Nature (2026). DOI: 10.1038/s41586-026-11166-3

This research relates to climate change primarily by showing how the global monsoon system has responded to rapid shifts in planetary boundary conditions in the past, conditions that are analogous in some ways to those changing today.

Core relevance

The 450,000- year speleothem record demonstrates that the South American Summer Monsoon (SASM) and Asian monsoon are usually out of phase (a “seesaw” driven largely by orbital- Milankovitch insolation differences).

However, they occasionally synchronize, both strengthening or, more concerningly, both weakening, during intervals of rapid change.

These synchronicity events (about ten identified) cluster around glacial terminations and warm interglacial/interstadial periods.⁠

Key drivers of those exceptions include:

  • Rising greenhouse- gas concentrations
  • Changes in cross- equatorial thermal gradients
  • Anomalous sea- surface temperatures in the Atlantic and Pacific
  • Disruptions to ocean circulation (including Atlantic Meridional Overturning Circulation, or AMOC, collapse or weakening)

In short, when ice sheets, carbon dioxide levels, ocean temperatures, and circulation shift quickly, the global monsoon can reorganize for millennia rather than simply following the slow orbital “clock”. Synchronous drying across both hemispheres would reduce freshwater availability in major monsoon regions at the same time.

Link to present- day and future climate change

  • Greenhouse gases and rapid forcing: Past synchronous events occurred when greenhouse gases rose (though more slowly than today). Modern CO₂ is increasing far faster than during most of the last 450,000 years. The paper notes that the monsoon is not rigidly locked to orbital cycles; it can flip modes when boundary conditions change rapidly, exactly the situation under (anthropogenic) warming.
  • Ocean circulation risks: Model comparisons (including AMOC “hosing” experiments) link high- latitude ocean changes to tropical rainfall reorganization. Ongoing observations and projections of AMOC weakening under climate change therefore raise the possibility of monsoon disruptions that are more simultaneous and less “seesaw- like.”
  • Water security: Monsoons supply freshwater to more than 2.7 billion people. Historical evidence of multi- millennial synchronous droughts underscores the risk that future reorganization could strain water resources across both hemispheres rather than allowing one region’s gains to offset another’s losses.
  • Not a direct prediction: The study is a paleoclimate reconstruction, not a future forecast. Orbital forcing today is different from glacial terminations, and human- driven change includes additional factors (aerosols, land- use change, etc.). Still, it supplies a long- term natural experiment showing the monsoon system’s sensitivity to fast shifts in ice, greenhouse gases, SSTs, and ocean circulation, the same variables that climate models project will continue changing this century.

In essence, the stalagmite record strengthens the scientific case that rapid climate change can push the global monsoon beyond its usual interhemispheric balance, with potentially widespread impacts on rainfall patterns and water availability. It does not claim that today’s warming will automatically produce the exact same synchronicity events, but it shows that such reorganization is physically possible and has occurred under analogous (if slower) past conditions.

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Interhemispheric monsoon dynamics over the past 450,000 years

Abstract (key points)

The global monsoon system supplies freshwater to much of Earth’s biota and human population. Milankovitch orbital variations in solar insolation are expected to drive long- term changes in the monsoon, and internal factors (ice cover, sea- surface temperatures) can also influence it. Southern Hemisphere monsoon records spanning multiple glacial– interglacial cycles have been scarce.

This study presents a 450,000- year record of South American Summer Monsoon (SASM) variability based on speleothem (stalagmite) oxygen- isotope (δ¹⁸O) data from the Amazon Basin (Peruvian Andes caves).

  • SASM variability and the Asian monsoon have been strikingly out of phase for most of this interval (a classic interhemispheric “seesaw”).
  • Occasional synchronous behaviour occurs in regions affected by both monsoons.
  • A synchronicity threshold is exceeded during ten events, including glacial terminations.
  • Comparison with palaeoclimate forcings indicates that greenhouse- gas concentrations, cross- equatorial thermal gradients, and Atlantic and Pacific sea- surface temperatures probably influence these synchronous intervals.

The record shows that the global monsoon can reorganize itself, especially during periods of rapidly changing planetary boundary conditions.

Additional details from the paper and related coverage

  • Data & methods: Speleothem δ¹⁸O records (validated by modern cave monitoring) combined with a nearby Lake Junín glacial record to separate local vs. regional signals. Uranium-thorium dating provides precise chronology. Compared with established Asian monsoon speleothem records (e.g., Cheng et al.).
  • Figures (from the page): Location of caves; assessment of local vs. regional SASM signals; comparisons with other records; synchronicity events vs. climate forcings; Pearson correlations between Andean and Asian records; tropical precipitation maps and modelled response to AMOC collapse.
  • Data & code availability: Data at NOAA NCEI (doi:10.25921/ecnf-7908); analysis code on CodeOcean; related model data on Zenodo.

The full text is behind a paywall/subscription. Summaries and “Behind the Paper” discussions are available via Nature research briefings and Springer Nature Communities.

Journal: Nature, 658, pages 943–950 (2026)

DOI: 10.1038/s41586-026-11166-3

Published: 14 October 2026

Authors: E. J. Olson,
D. P. Gillikin,
D. Parmenter,
S. Burns,
A. Verheyden,
O. Miyawaki,
M. Vuille,
L. F. Piccirillo,
R. Castro,
G. Yurivilca,
R. L. Edwards &
D. T. Rodbell

A horseback rider in a cowboy hat and coat, contemplatively looking off into the distance, with text overlay questioning when the climate has ever remained unchanged in Earth's history.

Slower Winds Boost Grassland Carbon Uptake by Enhancing Soil Moisture Retention

Wind speed is indeed emerging as a key, yet often underappreciated, regulator of Earth’s carbon and water cycles, particularly on land.

Wind speed is indeed emerging as a key, yet often underappreciated, regulator of Earth’s carbon and water cycles, particularly on land.

Wind stilling (the observed multi-decadal decline in near-surface wind speeds, aka “terrestrial stilling”) is significantly improving water-use efficiency (WUE) in global grasslands by enhancing soil moisture retention.

“Terrestrial stilling” (declining near-surface winds) has been observed in many regions, linked to factors like land-use changes, vegetation growth increasing surface roughness, and atmospheric circulation shifts. This study highlights a positive side effect for these ecosystems, adding nuance to climate impacts on carbon and water cycles.

A paper published today (May 13, 2026) in Science Advances finds that declining wind speeds (“terrestrial stilling”) are helping global grasslands become more efficient at taking up carbon while using less water.

_____________________________________________________________________________________

Wind stilling shapes grassland water use efficiency by enhancing soil moisture retention

That’s the title of the new Science Advances paper (published May 13, 2026).

Precise Mechanism:

Wind stilling doesn’t just passively reduce evaporation — it creates a coupled biophysical feedback loop that enhances ecosystem water-use efficiency (WUE_eco = GPP / ET) in grasslands:

Direct aerodynamic effect: Lower wind speed reduces boundary layer conductance (g_bw) to water vapor. This slows the removal of moist air near the surface/canopy, directly suppressing soil evaporation (the dominant component of ET in many grasslands) and canopy transpiration.

Indirect humidity feedback: Reduced vapor exchange increases near-surface relative humidity and lowers vapor pressure deficit (VPD) locally, further decreasing evaporative demand.

Soil moisture bridge: The suppressed ET leads to higher soil moisture (SM) retention. This is critical in water-limited grasslands, where plants are highly sensitive to soil drying.

Stomatal response: With better SM availability, plants increase stomatal conductance (keep stomata more open longer). This boosts CO₂ uptake (higher GPP/carbon gain) while the overall water loss (ET) rises less than proportionally — hence higher WUE.

Quantitative insight from the study:

A 1% decline in wind speed → +0.31% GPP but –0.65% ET (driven mostly by soil evaporation reduction), with SM increasing ~0.38%. Structural equation modeling (SEM) confirmed the dominant pathways: wind → lower g_bw + higher humidity → lower ET → higher SM → higher stomatal opening → higher GPP.

This loop is stronger under drier conditions, providing a natural buffer against drought intensification.

Why Grasslands Are Special

Low-stature vegetation minimizes vegetation-wind feedbacks (unlike forests, where greening increases surface roughness and can complicate stilling signals).

Grasslands experience more pronounced stilling than other biomes.

They are predominantly water-limited, making SM retention particularly impactful for carbon-water coupling.

Evidence Strength (Multi-Line Convergence)

Observations: 991 meteo stations + 13 eddy-covariance flux towers.

Remote sensing + reanalysis: Consistent negative WUE-wind sensitivity.

Modeling: CMIP6 simulations + targeted wind-manipulation experiments in CLM5 (Community Land Model) to isolate causality.

Spatial scale: >80% of global grasslands show WUE gains from stilling.

Contribution:

Wind stilling explains 7.7–25.7% of observed/projected WUE increases — second only to CO₂ fertilization.

Temporal Dynamics (1983–2100)

Strong stilling 1983–2010 → WUE boost.

Partial recovery ~2011–2028.

Renewed (and potentially stronger) stilling post-2029, especially under high-emission scenarios.

Key caveat: CMIP6 models underestimate the magnitude of wind declines, implying real-world WUE gains and drought resilience may be larger than current projections.

This aligns with related work by the same team showing wind stilling boosts global vegetation GPP (with grasslands contributing disproportionately). It adds nuance to climate impacts: while warming/VPD increases can stress ecosystems, stilling provides a counteracting positive effect on carbon-water efficiency.

Limitations:

Benefits may saturate or interact negatively with extreme events (e.g., if precipitation changes dominate).

Attribution relies on statistical isolation and model experiments; real-world confounding (e.g., land use, aerosols affecting circulation) exists.

Future projections depend on uncertain wind trends (driven by land-use change, atmospheric circulation shifts, etc.).

This suggests grasslands have more built-in resilience to climate change than previously modeled, particularly for carbon sequestration and drought tolerance. It could inform conservation priorities, grazing management, and expectations for terrestrial carbon sinks. However, it doesn’t negate other threats like conversion to agriculture or extreme heat.

Published:  Science Advances

DOI: 10.1126/sciadv.aee4995

Authors: Haohao Wu, Congsheng Fu, Philippe Ciais, Zelalem A. Mekonnen, Lingling Zhang, Qing Zhu Jiafu Mao, Jianyao Chen, Dagang Wang and Guishan Yang 

Abstract

Covering more than 40% of Earth’s vegetated surface, grasslands critically regulate terrestrial carbon and water cycles. Their ecosystem water use efficiency (WUEeco), the ratio of carbon uptake to water loss, governs drought resilience in these water-limited ecosystems. While global terrestrial wind speed declined substantially from the 1960s to 2000s followed by a recovery in the subsequent decade, the extent and mechanisms of its influence on grassland WUEeco remain poorly understood. Using site observations, satellite data, Earth system models, and wind manipulation experiments, we found a consistent negative sensitivity of grassland WUEeco to wind speed. Mechanistically, declining winds reduce evaporative water loss, improve soil moisture, and promote stomatal opening, thereby enhancing carbon uptake. Wind speed changes accounted for 7.7 to 25.7% of WUEeco increases under historical and future climates, making wind the second most important climatic driver after atmospheric carbon dioxide. Since Earth system models underestimate observed wind speed declines, future WUEeco increases and drought resilience may exceed current projections for global grassland.

No, New York Times, We Don’t Need to Dam the Bering Strait

The New York Times (NYT) reports in “A New Idea to Save the Climate? Dam the Bering Strait.” that scientists have proposed building a 50-mile-long dam between Alaska and Russia to stabilize the Atlantic Meridional Overturning Circulation (AMOC) in order to prevent climate catastrophe. This is a seriously risky idea.

From ClimateRealism

By Anthony Watts

The New York Times (NYT) reports in “A New Idea to Save the Climate? Dam the Bering Strait.” that scientists have proposed building a 50-mile-long dam between Alaska and Russia to stabilize the Atlantic Meridional Overturning Circulation (AMOC) in order to prevent climate catastrophe. This is a seriously risky idea. The proposal is not an engineering plan grounded in observational need, but rather is computer-model thought experiment based on speculative tipping-point scenarios not justified by data concerning the AMOC or an understanding of what the possible future consequences might be for humans, the oceans, and sea life.

The author describes an article published in Science Advances where the idea of a cross continental dam across the Bering Strait is proposed as a “proof of concept,” noting that the dam could, under certain modeled conditions, prevent an AMOC collapse. It further explains that the findings come from a computer model of Earth’s climate, not from direct evidence that the AMOC is about to fail. That distinction is critical.

As Climate Realism has reported in dozens of articles, the AMOC has been the subject of repeated alarmist headlines over the past decade. Some studies have projected weakening. Others have suggested relative stability. Still others have found mechanisms, such as Southern Ocean wind-driven upwelling, which may be strengthening the AMOC. The scientific literature has moved in three directions: collapse, steady-state persistence, and even partial strengthening depending on assumptions.

What has not emerged is observational evidence of imminent shutdown.

The NYT acknowledges that “the uncertainty is very, very large,” quoting a climate scientist who says researchers do not know how close the AMOC is to collapse.

The proposed intervention outlined in the study would block the Bering Strait to alter freshwater flows between the Pacific, Arctic, and Atlantic Oceans. The model simulations suggest that if the AMOC is still strong, closing the strait might help maintain salinity and stabilize circulation. But if the AMOC is already weak, the same intervention could accelerate collapse.

In other words, the intervention could help, harm, or do nothing depending on timing and initial conditions.

That is not a control mechanism; it is a Las Vegas style gamble on a global scale.

The proposal relies on climate model outputs run under specific forcing assumptions. Models are useful tools, but they are not reality. Ocean circulation at the scale of the AMOC involves complex thermohaline processes, wind forcing, stratification, and deep-water formation, most of which aren’t well understood and, at best if accounted for at all in climate models, are only imperfectly represented even in state-of-the-art systems.

Moreover, the underlying modeling framework uses coarse resolution that does not fully resolve the Bering Strait’s dynamics, instead parameterizing throughflow behavior. From that abstraction comes a proposal to physically block a major ocean gateway. The AMOC is critical to coastal communities and the health and lifecycles of sea life. There is no evidence the models accounted for ancillary impacts on these communities or species – the only focus was keeping the AMOC from collapsing, though, it turns out, the proposed cure may, in fact, cause the collapse.

The scale of the proposal itself should give pause. An 80-kilometer barrier in Arctic conditions across an international boundary is not comparable to ordinary coastal infrastructure. The NYT notes that once built, such a structure “couldn’t easily be taken down.” Geoengineering does not come with an undo button.

The Bering Strait is also a biological choke point linking Pacific and Arctic ecosystems. Blocking it would alter nutrient transport, salinity gradients, and marine migration pathways. The ecological consequences are acknowledged only briefly in the NYT coverage, yet they could be profound.

There is also a glaring contradiction embedded in this narrative. For years, readers have been told that the AMOC is fragile, sensitive to freshwater perturbations, and prone to tipping points. If that is true, why would deliberately shutting off a major ocean exchange be considered a sane idea? If the system is robust enough to tolerate such intervention, then perhaps the entire AMOC collapse narrative deserves reconsideration.

The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) states that while AMOC weakening is likely under high-emissions scenarios – scenarios which are not just improbable but likely impossible, there is low confidence in a collapse before 2100. That is a far cry from imminent shutdown requiring Arctic mega-dams. The NYT article concedes that scientists do not know how close the AMOC is to collapse.

What we are seeing is a pattern. As climate modeling grows more dramatic, proposed interventions grow more extreme: carbon capture and permanent storage; solar radiation blocking; and now ocean dams. Each rest on the assumption that models reliably predict nonlinear system behavior decades in advance.

Before entertaining planetary-scale geoengineering, a simpler question should be asked: where is the observational evidence of near-term failure? The RAPID array has been monitoring the AMOC since 2004 and shows variability but not collapse. Paleo records indicate multidecadal fluctuations long before industrial emissions.

Ocean circulation is complex. Uncertainty is high. Models disagree. And now, on that uncertain foundation, we are asked to consider blocking an ocean strait. This is mad scientists from the movies type stuff. The NYT shouldn’t have even given this proposal an audience.

This is not sober climate reporting by The New York Times. It amplifies a speculative modeling exercise as if it were visionary thinking. When the cure involves restructuring planetary oceanic circulation based on uncertain and likely flawed simulations, skepticism is not denial, it is prudence in the face of a crazy idea with unknown consequences. The evidence that humans actually control the climate is exceedingly weak, but this proposal, if enacted, would certainly cause unforetold and unpredictable climate disruptions that we haven’t even begun to consider.

Crazy plans don’t become reasonable just because some group of scientists propose them. And crazy plans, just because they are floated, don’t necessarily merit the attention of a major media outlet, promoting it as a reasonable idea.

The Question Climate Alarmists Avoid: What IS the Correct CO₂ Concentration?

If CO₂ is classified as a pollutant (as per the U.S. EPA’s 2009 Endangerment Finding, which enabled regulation under the Clean Air Act), then there must be a scientifically defensible “safe” or “correct” threshold concentration in the atmosphere.

If CO₂ is classified as a pollutant (as per the U.S. EPA’s 2009 Endangerment Finding, which enabled regulation under the Clean Air Act), then there must be a scientifically defensible “safe” or “correct” threshold concentration in the atmosphere. Yet climate policy rarely specifies one beyond implying pre-industrial levels (~280 ppm) as the ideal baseline to return to.

No Clear Threshold Defined: Policies aim to limit warming (e.g., to 1.5–2°C) via emissions cuts, but don’t pinpoint an exact “safe” ppm level for CO₂. Is it 280 ppm (pre-industrial)? 350 ppm? 400 ppm?

Over the past 800,000 years (from ice cores), CO₂ fluctuated between 180–300 ppm during glacial-interglacial cycles.

For most of the Phanerozoic eon (last ~550 million years), CO₂ was often 1,000–4,000+ ppm during periods of lush vegetation and no “icehouse” Earth.

Photosynthesis responds strongly (nonlinearly) to CO₂ increases from ~280 ppm up to ~1,100 ppm. Commercial greenhouses deliberately enrich air to 800–1,000 ppm to boost crop yields.

Everyday examples undercut toxicity claims: Exhaled breath is 40,000 ppm CO₂.

Even burning all known fossil fuels might only reach ~1,000 ppm globally.

In a hypothetical “post-Endangerment” scenario, what concentration should we target?

_________________________________________________________________________________________________________

What Is the Correct CO2 Concentration?

From Irrational Fear

By Dr. Matthew Wielicki

A Scientific Thought Experiment in a Post-Endangerment World

The 2009 Endangerment Finding treated carbon dioxide as a pollutant that threatens public health and welfare. For more than a decade, that designation has functioned as the legal foundation for regulating fossil fuels, electricity generation, transportation, and much of the modern economy.

Now that the Finding is being reconsidered, it is worth stepping back from the regulatory framework and asking a much more basic scientific question.

What is the correct atmospheric concentration of CO2?

If carbon dioxide is truly a pollutant, then there must be a threshold. There must be some identifiable boundary at which CO2 shifts from being part of the natural carbon cycle to being harmful in a biological or climatic sense. If such a boundary exists, it should be visible in geology, in plant physiology, or in the empirical record of Earth’s climate.

But when we begin to examine those lines of evidence, the clarity we are promised does not appear.


In The Endangerment Finding Was Pre-Cooked, I walked through the Phanerozoic reconstruction of atmospheric CO2. Over the last 550 million years, concentrations frequently exceeded 1000 parts per million and at times reached several thousand.

Life did not collapse under those conditions. On the contrary, biodiversity expanded. Forests flourished. Marine ecosystems diversified. The idea that 400 ppm constitutes dirty air sits uneasily beside a geological record in which far higher concentrations coincided with biological abundance.

If today’s atmosphere is “endangering,” then vast stretches of Earth’s history would need to be reclassified as ecologically reckless. That conclusion should at least give us pause.

In Does More CO2 = More Heat?, I also explored the complex relationship between CO2 and temperature over deep time. The geological record does not display a simple linear mapping between atmospheric concentration and climate state.

Source: Does More CO2 = More Heat?

Continental configuration, ocean circulation, solar luminosity, volcanic outgassing, and feedback processes all shape global temperature. CO2 plays a role, but it is not the only control knob.

If there is an upper danger threshold, it is not obvious in deep time.

The Ice Age Constraint

The more recent record complicates things further.

In Atmospheric CO2 Concentrations of the Past and Do We Really Know the Surface Temperature or CO2 Concentration of the Past?, I discussed the proxy records and their limitations. Even accepting the ice core framework at face value, atmospheric CO2 over the past 800,000 years fluctuated between roughly 180 and 300 ppm.

Those low points coincided with massive continental ice sheets. Glacial maxima were not periods of ecological flourishing. They were periods of climatic severity and instability.

Pre-industrial levels near 280 ppm did not represent a golden age of climatic balance. They were part of a cycle of repeated glaciations driven by orbital forcing. The Earth system oscillated between ice ages lasting nearly 100,000 years and comparatively brief interglacials.

That history raises an uncomfortable possibility.

Perhaps 280 ppm was not an optimal equilibrium. Perhaps it was closer to a lower boundary of climatic stability.

The Modern Biosphere Response

Meanwhile, as CO2 rose from roughly 280 ppm to more than 420 ppm, something measurable occurred.

In Greening Earth and Booming Crops, I examined satellite evidence showing widespread increases in global leaf area. Agricultural production has expanded dramatically over the past several decades. Water use efficiency has improved under elevated CO2 conditions.

Commercial greenhouse operators routinely enrich indoor air to concentrations between 800 and 1000 ppm in order to maximize plant growth. They do not regard 280 ppm as biologically ideal.

CO2 is not a trace contaminant in plant physiology. It is the fundamental substrate of photosynthesis.

If rising CO2 were inherently degrading the biosphere, we would not expect to observe widespread greening.

The Sea Level Complication

Perhaps, then, the danger lies in the sea level.

That argument is often presented as straightforward. Higher CO2 increases radiative forcing. Higher temperatures melt ice. Melting ice raises the sea level.

But in Sea Levels Were Significantly Higher in the Mid to Late Holocene at Pre Industrial Levels of CO2, I reviewed multiple peer-reviewed reconstructions showing that regional sea levels during the mid to late Holocene were, in many places, higher than today. These highstands occurred while atmospheric CO2 remained near 260 to 280 ppm.

Evidence from the Arabian Gulf, the southwestern Atlantic, and the southeast Australian coast indicates elevated sea levels under what we now describe as safe pre-industrial concentrations.

This does not mean CO2 has no climatic influence. It does mean that sea level does not map cleanly or uniquely onto atmospheric concentration. Glacio isostatic adjustment, meltwater redistribution, and regional dynamics complicate the picture.

Once again, the boundary between safe and dangerous becomes difficult to identify.

The Asymmetry

Taken together, these observations produce a striking asymmetry.

There is clear evidence that very low CO2 concentrations coincide with biospheric stress and glacial amplification.

There is far less clarity about a specific upper danger threshold anywhere near modern levels.

And yet policy treats 280 ppm as a moral baseline.

Why?

Why was the concentration that happened to exist before industrialization elevated to the status of climatic ideal?

Below the paywall, I will attempt to answer the original question directly. Not rhetorically. Not politically. But analytically.

If the objective were maximizing biospheric productivity, minimizing glacial instability, preserving adaptability, and supporting human flourishing, what atmospheric CO2 range would we rationally choose?

Subscribers receive the full stability framework, the plant physiology constraints, the radiative forcing context, and a direct answer grounded in the evidence reviewed above.

New Study: Today’s Climate Models ‘Do Not Agree with Reality’ And Thus Their Usefulness Is ‘Doubtful’

Because the current state-of-the-art general circulation models (GCMs) cannot simulate the trends and variances in global precipitation over the last 84 years (1940-2023), their usefulness should be reconsidered.

From NoTrickZone

By Kenneth Richard

Because the current state-of-the-art general circulation models (GCMs) cannot simulate the trends and variances in global precipitation over the last 84 years (1940-2023), their usefulness should be reconsidered.

Hydrological processes – ocean circulation, water vapor, clouds – are key components of climate, easily overshadowing the impact of anthropogenic CO2 emissions by a factor of 2,100 (Koutsoyiannis, 2021).

The effect that clouds cover variability has on surface temperature is so uncertain, and our cloud-effect measurement capacities are so primitive, even NASA has had to admit that “today’s models must be improved by about a hundredfold in accuracy” to even begin to attribute current or future temperature changes to increases in atmospheric CO2.

Image Source: NASA.gov

In that vein, a new paper published by Dr. Koutsoyiannis, a hydrologist, statistically assesses the utility of today’s climate models. He documents the general circulation models’ capacity to simulate trends and variability in global (hemispheric) precipitation since 1940.

The results are not encouraging. The best computer models we have cannot accurately simulate what occurs in the real world.

“It turns out that the precipitation simulated by the climate models does not agree with reality on the annual scale…”

When the models are tuned to assess what happens at a continental scale, their performance plunges from poor to worse. These modeling failures cast doubt on whether GCMs are even worth using at all.

“[W]hen the areal scale is decreased from hemispheric to continental, i.e., when Europe is examined, the model performance is poor even at large time scales.”

“Therefore, the usefulness of climate model results for hydrological purposes is doubtful.”

Image Source: Koutsoyiannis, 2025

,water-17-00264-v2Herunterladen

Arthur Viterito:”I think the temperatures are going to cool down” | Tom Nelson Pod #175

Art Viterito is a retired Professor of Geography who taught at the University of Pittsburgh, the George Washington University and the College of Southern Maryland.

Art Viterito is a retired Professor of Geography who taught at the University of Pittsburgh, the George Washington University and the College of Southern Maryland.

Art received his Ph.D. from the University of Denver with specialties in climatology, physical geography, and geographic information systems. He has published research in the areas of urban climatology and global climate change. His work in urban climatology was cited in the first report of the Intergovernmental Panel on Climate Change, and his most recent work on the role of oceanic geothermal heat in modulating climate has been cited by the Nongovernmental International Panel on Climate Change.

Art is a member of the National Association of Scholars, and is a policy advisor to the Heartland Institute. He currently resides in Vero Beach, Florida.

00:00 Introduction and Guest Background
00:38 Understanding the Geothermal Paradox
01:24 Geothermal Heat and Global Temperatures
01:57 Exploring the Mid Ocean Ridge System
04:56 The Geothermal Paradox and its Impact
06:38 The Role of Seismic Activity in Global Warming
08:30 The Impact of Geothermal Heating on Ocean Circulation
14:22 The Connection Between Seismic Activity and Global Temperatures
21:27 Understanding the Impact of Geothermal Heating on Climate
46:02 Conclusion and Future Predictions

Climate alarmists DENY the science of the world’s top ocean scientists!

A team of top expert oceanographers from Harvard and MIT, published the attached graph in the paper Liang (2015) Vertical Redistribution of Oceanic Heat Content, illustrating how oceans absorb heat in the tropics, and due to ocean circulation, release that heat as ocean currents move that heat towards the poles.

By Jim Steele

Jim Steele

A team of top expert oceanographers from Harvard and MIT, published the attached graph in the paper Liang (2015) Vertical Redistribution of Oceanic Heat Content, illustrating how oceans absorb heat in the tropics, and due to ocean circulation, release that heat as ocean currents move that heat towards the poles. Ninety nine percent of all climate scientists have always acknowledged this dynamic.

Clearly greenhouse gases are not adding heat to every region of the oceans, despite claims oceans are absorbing 90% of greenhouse warming. The regions in white represent where any absorption of heat, whether via solar or greenhouse radiation, is quickly radiated back to space with no net warming.

The blue regions (negative heat flux) represent regions where the oceans absorb more heat than is locally released. Those blue regions represent La Nina-like conditions where upwelling of cool subsurface waters reduce cloud cover and intensify deeper solar heating of the oceans.

The red (positive heat flux) represents regions where the oceans release more heat than has been locally absorbed, whether solar or greenhouse energy. Ocean circulation has simply transported excess absorbed heat out of the tropical blue regions, into the red regions where it is released, such as along the Gulf Stream and in Arctic Ocean!

During the Little Ice Age, the oceans were in a El Nino-like state, during which the oceans absorbed less solar heat in the tropics, and thus, absorbed and transported less heat towards the poles. This resulted in the cooling of the northern hemisphere and glacier advances.

Since 1850, La Nina-like conditions have dominated, which promoted the increased absorption of solar heat in tropical oceans. Unlike solar energy, greenhouse infrared does not penetrate deeper than a few microns into the ocean surface, so that any infrared greenhouse heat that is absorbed by the oceans is also quickly released back to space.

This is why only the eastern tropical oceans absorb and store solar heat, while the remaining ocean regions (represented in white) do not!

New Study: Climate Models Mired In ‘Terra Incognita’ – Lack The Resolution To Model Climate Change

“…models are pushing further and further into the domain of the ‘terra incognita.’” – Stephens et al., 2023

From NoTricksZone

By Kenneth Richard on 3. August 2023

“…models are pushing further and further into the domain of the ‘terra incognita.’” – Stephens et al., 2023

It is well established in climate science that water (1) “exerts a fundamental influence on the physical climate system and on climate change,” (2) clouds “control the planetary albedo and the amount of solar radiation reaching the surface,” and (3) “ocean circulation…determines and modulates the climate of many regions of the world.”

But there’s a rather large problem here. When it comes to climate models, the unknown, unexplored “terra incognita zone is what we experience today.”

“Existing climate models…cannot resolve the detailed structure and life cycles of systems such as tropical cyclones, depressions, and persistent high pressure systems, which are key in the coupling of the energy and water cycle.”

While ocean circulation determines the regional climate, “present day global models are also unable to resolve ocean currents that are fundamental to climate variability.”

At the surface-troposphere altitude, convection dominates heat transfer. While radiation only accounts for 8% of the heat transfer process here, convection accounts for 67%. But today’s climate models cannot “resolve convection.”

“There is now compelling evidence the lack of resolution of coarse global models and even coarsely resolved mesoscale cloud models and the inability to explicitly resolve convection specifically is a major obstacle in making the advances needed to confront important Earth science challenges of today.”

Assessing Earth’s top-of-atmosphere (TOA) energy imbalance (EEI) is fundamental to determining the extent and rate of global (ocean) warming. A measured accuracy of less than ±0.3 W/m² (±0.1 W/m²) is required for attribution (to, for example, human CO2 emissions), and yet the absolute accuracy of TOA measurements is ±2 W/m², and long-term estimates of global mean EEI are “not possible.”

“…none of the techniques available today enable us to estimate the EEI with the perceived required accuracy less than ±0.3 W/m², let alone with an aspirational accuracy of ±0.1 W/m².”

Claiming that we know it is humans controlling the climate today is thus a statement of belief. The claim has no scientific meaning or testability. Indeed, it is unfalsifiable.

Image Source: Stephens et al., 2023

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“The Day After Tomorrow” to Happen in the Next Few Decades?

A claim that a “The Day After Tomorrow” style global warming driven ice age is imminent – but we’ve been looking at the wrong ocean.

From Watts Up With That?

A claim that a “The Day After Tomorrow” style global warming driven ice age is imminent – but we’ve been looking at the wrong ocean.

New Research Sparks Concerns That Ocean Circulation Will Collapse

Scientists have long feared that warming could cause a breakdown of ocean circulation in the North Atlantic. But new research finds the real risk lies in Antarctica’s waters, where melting could disrupt currents in the next few decades, with profound impacts on global climate.

BY FRED PEARCE • APRIL 18, 2023

It is being hailed as a sea change in scientific understanding of the global ocean circulation system and how it will respond as the world heats up. A doomsday scenario involving the collapse of the circulation — previously portrayed in both peer-reviewed research and the climate disaster movie The Day After Tomorrow — came a lot closer in the last month. But rather than playing out in the far North Atlantic, as previously assumed, it now seems much more likely at the opposite end of the planet. 

A new analysis by Australian and American researchers, using new and more detailed modeling of the oceans, predicts that the long-feared turn-off of the circulation will likely occur in the Southern Ocean, as billions of tons of ice melt on the land mass of Antarctica. And rather than being more than a century away, as models predict for the North Atlantic, it could happen within the next three decades. 

Leading ocean and climate researchers not involved in the study who were contacted for comment praised the findings. “This is a really important paper,” says Stefan Rahmstorf, an oceanographer and head of earth system analysis at the Potsdam Institute for Climate Impact Research in Germany. “I think the method and model are convincing.”

…Read more: https://e360.yale.edu/features/climate-change-ocean-circulation-collapse-antarctica

The abstract of the paper;

Abyssal ocean overturning slowdown and warming driven by Antarctic meltwater

Qian Li 1, Matthew H England 2, Andrew McC Hogg 3, Stephen R Rintoul 4 5, Adele K Morrison 6

The abyssal ocean circulation is a key component of the global meridional overturning circulation, cycling heat, carbon, oxygen and nutrients throughout the world ocean1,2. The strongest historical trend observed in the abyssal ocean is warming at high southern latitudes2-4, yet it is unclear what processes have driven this warming, and whether this warming is linked to a slowdown in the ocean’s overturning circulation. Furthermore, attributing change to specific drivers is difficult owing to limited measurements, and because coupled climate models exhibit biases in the region5-7. In addition, future change remains uncertain, with the latest coordinated climate model projections not accounting for dynamic ice-sheet melt. Here we use a transient forced high-resolution coupled ocean-sea-ice model to show that under a high-emissions scenario, abyssal warming is set to accelerate over the next 30 years. We find that meltwater input around Antarctica drives a contraction of Antarctic Bottom Water (AABW), opening a pathway that allows warm Circumpolar Deep Water greater access to the continental shelf. The reduction in AABW formation results in warming and ageing of the abyssal ocean, consistent with recent measurements. In contrast, projected wind and thermal forcing has little impact on the properties, age and volume of AABW. These results highlight the critical importance of Antarctic meltwater in setting the abyssal ocean overturning, with implications for global ocean biogeochemistry and climate that could last for centuries.Read more: https://pubmed.ncbi.nlm.nih.gov/36991191/

Unless you are the kind of person who has a poster of Greta in your bedroom, global warming isn’t actually that scary. For most people, global warming would mean more BBQ weather, more time swimming in the pool, long summer walks.

But an abrupt return to ice age conditions would be truly scary and devastating – which is why “The Day After Tomorrow” was such a successful film. And it actually happened once, though circumstances were very different – today we don’t have a gigantic glacial lake caused by melting of the North American Ice Sheet, which is poised to collapse into the landlocked Arctic ocean, like we did last time.

Nevertheless the ice age claim is a sliver more plausible than most of the tipping point nonsense climate scientists push. Of course for any of this to happen, the Antarctic would need to actually warm. Robust warming has not exactly been a feature of the last century of Antarctic climate observations.

One benefit of making such predictions is that if global temperatures take a dive, scientists have it covered with an each way bet on the future trajectory of the global climate – though I’m not suggesting this is the motivation for such predictions.

Whatever happens, it will still all be our fault of course.