global warming

Plant Evapotranspiration Reduction Causes Global Warming, not CO2 GHG

Wryheat note: The following is an original research paper written by David Motes, a chemical engineer with 43 years professional experience. Below I provide the paper abstract with a link to the full paper as a PDF file. The full paper discusses nine problems with the Greenhouse hypothesis and then presents Motes’ alternative hypothesis. Mr. Motes may be contacted at

Plant Evapotranspiration Reduction Causes Global Warming, not CO2 GHG
by David Motes

Anthropogenic (manmade) Global Warming (AGW) has many causes. CO2 drives recent global warming by Plant Evapotranspiration Reduction (PER), not CO2 Green House Gas (GHG) theory. For example, the irrefutable correlation between global temperature and CO2 concentration for the last 800+ thousand years can only be explained by plant evapotranspiration increases / decreases and not by the prevailing CO2 GHG effects. The prevailing GHG theory cannot explain why CO2 increased or decreased or the carbon source prior to fossil fuel emissions, but PER does. Quantitative evidence for PER driving global warming over CO2 GHG follows:

  1. Using a NOAA (National Oceanic and Atmospheric Agency) energy balance, the scientific consensus 0.70%/year plant water use efficiency increase (evapotranspiration reduction) caused by higher CO2 generates a calculated temperature rise 12 times the actual measured temperature rise.
  2. Similarly, the measured 0.23%/year deforestation and land use change (causing same plant evapotranspiration 0.23%/year reduction) generates a calculated temperature rise 3 times the actual measured temperature rise. From scientific consensus, global development, deforestation, commercial farming, and commercial ranching have reduced plants (consequently evapotranspiration) since the 1960 industrial global expansion. Explaining the 12 and 3 factors:
    A. The actual temperature increase was less due to increasing infrared radiation emitted by the atmosphere to space from that same temperature rise.
    B. Terrestrial biomass increases in deserts and arid lands partially offset the measured evapotranspiration reductions.
  3. Only 8% photosynthesis reduction is equivalent to all 2020 fossil fuel CO2 emissions.
  4. Water vapor is 192 times stronger GHG than CO2 when you factor in both infrared absorbances and atmospheric concentrations. Consequently, CO2 GHG contributes only ~0.3% to AGW, balance driven by PER.
  5. The PER impact on global warming is demonstrated in real life at many locations such as city centers being 1-3 °C warmer than the surrounding suburbs or countryside. Secondly, the air is 3-4oC cooler above a green grass lawn vs a black asphalt parking lot. PER provides an explanation for the undeniable Global Warming that fits all the scientific data (climate history, carbon sources, carbon mass balances, energy balances, GHG parameters, humidity data, etc.) as quantified and explained in this engineering and scientific study. “Greening” the earth (increasing plant life) is less expensive and substantially more effective than just reducing annual fossil fuel CO2 emissions (contributes only 1% of existing atmospheric CO2).

Quantified problems with the proposed CO2 annual emission reduction
plans follow:

  1. Will certainly fail by focusing on the 1%/year contribution and foolishly ignoring the 99% existing atmospheric CO2.
  2. Focuses solely on reducing the 8% CO2 emissions driver, while ignoring the 92% plant life CO2 driver. Prior to attempting to resolve the current global warming problem, we should identify, quantify, and confirm the root cause(s) and magnitudes. Then, solutions become clearer and more cost effective.

Read the full paper:

CO2 & Global Temperature 19apr2021

The “Social Cost of Carbon” Scam Revisited

As I wrote in 2015:

The “social cost of carbon”(SCC) is a computer-generated artifice that puts a dollar figure on the alleged environmental and economic damage caused by carbon dioxide emissions from burning fossil fuels. This number is supposed to allow bureaucrats to offset the alleged damage through regulation and taxes, i.e., it will increase the cost of electricity and gasoline. The computer models fail to take into account the benefits of carbon dioxide, such as making our crops more robust and more water efficient. Also, there is absolutely no physical evidence that our carbon dioxide emissions have any significant role in controlling global climate. (Read more on Wryheat)

Recent articles on SCC:

Why ‘Social Cost of Carbon’ Is Most Useless Number You’ve Never Heard Of

by Kevin Dayaratna

Dubbed by some as “the most important number you’ve never heard of,” the social cost of carbon is defined as the economic damages associated with a ton of carbon dioxide emissions across a particular time horizon. That metric, relied upon heavily by the Obama administration, has been used as the basis for regulatory policy in the energy sector of the economy. Three sets of statistical models are used to estimate the social cost of carbon. Social cost of carbon estimates are based on very questionable assumptions regarding the climate’s sensitivity to carbon dioxide emissions, naive projections reaching 300 years into the future, and ignorance of discount rate recommendations by the Office of Management and Budget regarding cost-benefit analysis. Our results tell the same story: Assumptions made by modelers can drastically change the purported estimates and thus beef up the damages as much as they want. (Read more)

Social Cost of Carbon May Be Social Benefit of Carbon, Economist Finds

by James Taylor (commenting on Dauaratna’s paper)

The Biden administration made headlines by imposing a “social cost of carbon” – to be factored into federal cost-benefit analysis – that is more than six times higher than the social cost of carbon determined by the Trump administration. However, economist and data scientist Kevin Dayaratna published an article documenting that the alleged social “cost” of carbon may actually be a social “benefit” of carbon. In an article for the Daily Signal, Dayaratna observes that any accurate assessment of the social cost of carbon must include social benefits as well as merely social harms. Importantly, Dayaratna observes that any sound cost/benefit assessment must take into account “positive agricultural feedback effects associated with carbon dioxide emissions.”

“In fact, we found that under very reasonable assumptions, those benefits can outweigh the costs, suggesting that the social cost of carbon can indeed be negative,” Dayaratna writes. “The policy implication of a negative social cost of carbon is that the government should not be taxing carbon dioxide emissions, but should be subsidizing it instead.” (Source)

See also: The Social Cost of Carbon Fantasy and

Biden’s Arbitrary Social Cost of Carbon: What You Need to Know

12 State Attorneys General Sue Biden Admin Over Its Climate Policies The lawsuit said Biden’s executive order enables regulatory agencies to place restrictions on nearly every aspect of Americans’ lives in order to cut back on greenhouse gas emissions.

For a tutorial on climate read:

A Review of the state of Climate Science

Bjorn Lomborg on how to deal with climate change

Dr. Bjorn Lomborg is president of the Copenhagen Consensus Center, visiting fellow at the Hoover Institution, Stanford University, and visiting professor at Copenhagen Business School. The Copenhagen Consensus Center is a think-tank that researches the smartest ways to do good.

His new paper: Welfare in the 21st century: Increasing development, reducing inequality, the impact of climate change, and the cost of climate policies


Climate change is real and its impacts are mostly negative, but common portrayals of devastation are unfounded. Scenarios set out under the UN Climate Panel (IPCC) show human welfare will likely increase to 450% of today’s welfare over the 21st century. Climate damages will reduce this welfare increase to 434%.

Arguments for devastation typically claim that extreme weather (like droughts, floods, wildfires, and hurricanes) is already worsening because of climate change. This is mostly misleading and inconsistent with the IPCC literature. For instance, the IPCC finds no trend for global hurricane frequency and has low confidence in attribution of changes to human activity, while the US has not seen an increase in landfalling hurricanes since 1900. Global death risk from extreme weather has declined 99% over 100 years and global costs have declined 26% over the last 28 years.

Arguments for devastation typically ignore adaptation, which will reduce vulnerability dramatically. While climate research suggests that fewer but stronger future hurricanes will increase damages, this effect will be countered by richer and more resilient societies. Global cost of hurricanes will likely decline from 0.04% of GDP today to 0.02% in 2100.

Climate-economic research shows that the total cost from untreated climate change is negative but moderate, likely equivalent to a 3.6% reduction in total GDP.

Climate policies also have costs that often vastly outweigh their climate benefits. The Paris Agreement, if fully implemented, will cost $819–$1,890 billion per year in 2030, yet will reduce emissions by just 1% of what is needed to limit average global temperature rise to 1.5°C. Each dollar spent on Paris will likely produce climate benefits worth 11¢.

Long-term impacts of climate policy can cost even more. The IPCC’s two best future scenarios are the “sustainable” SSP1 and the “fossil-fuel driven” SSP5. Current climate-focused attitudes suggest we aim for the “sustainable” world, but the higher economic growth in SSP5 actually leads to much greater welfare for humanity. After adjusting for climate damages, SSP5 will on average leave grandchildren of today’s poor $48,000 better off every year. It will reduce poverty by 26 million each year until 2050, inequality will be lower, and more than 80 million premature deaths will be avoided.

Using carbon taxes, an optimal realistic climate policy can aggressively reduce emissions and reduce the global temperature increase from 4.1°C in 2100 to 3.75°C. This will cost $18 trillion, but deliver climate benefits worth twice that. The popular 2°C target, in contrast, is unrealistic and would leave the world more than $250 trillion worse off. *

The most effective climate policy is increasing investment in green R&D to make future decarbonization much cheaper. This can deliver $11 of climate benefits for each dollar spent.

More effective climate policies can help the world do better. The current climate discourse leads to wasteful climate policies, diverting attention and funds from more effective ways to improve the world.

This article will outline how to establish a rational climate policy in the context of many other, competing global issues. Read full paper: 

*Wryheat comment: I disagree with Lomborg’s stance on “carbon taxes” because where they have been imposed show that they fail to deliver advertised benefits, see:

Carbon Tax Failures – Lessons from Australia and Germany

See also:

A Review of the state of Climate Science

The Fortuitous Link Between CO2 Emissions and Economic Growth (video)

Is Rising Atmospheric CO2 Causing Dangerous Global Warming? (video)

Many people are concerned about the potential impacts of rising levels of atmospheric CO2. For years they have been bombarded with claims that unless its concentration is slowed or even reduced, dangerous global warming will ensue, producing all sorts of undesirable consequences with little to no positive effects. Watch this video to lean why this scenario is unlikely to occur and why CO2 is not the all-important driver of temperature that climate alarmists make it out to be.

Hurricane strength and frequency just part of natural variation

The several recent hurricanes making landfall in the southeastern U.S. have spawned claims that they are the result of global warming. However, real data show that these hurricanes are consistent with natural variation. The following graphs were constructed by meteorologist Dr. Ryan N. Maue, who has recently been appointed as chief scientist at NOAA, the National Oceanic and Atmospheric Administration. See his website:

Hurricane Frequency

On the graph below, the upper line shows all hurricanes with wind speeds of greater than 64 knots. The bottom line show major hurricanes with wind speeds of greater than 96 knots. As you can see, overall, there has been no increase in frequency.

Hurricane Strength

Hurricane strength is measured as “accumulated cyclone energy” ACE. In the graph below, the upper line is global, the bottom line is for the northern hemisphere.


Dr. Maue notes:

“Tropical cyclone accumulated cyclone energy (ACE) has exhibited strikingly large global interannual variability during the past 40-years. In the pentad since 2006, Northern Hemisphere and global tropical cyclone ACE has decreased dramatically to the lowest levels since the late 1970s. Additionally, the frequency of tropical cyclones has reached a historical low. Here evidence is presented demonstrating that considerable variability in tropical cyclone ACE is associated with the evolution of the character of observed large-scale climate mechanisms including the El Nino Southern Oscillation and Pacific Decadal Oscillation. In contrast to record quiet North Pacific tropical cyclone activity in 2010, the North Atlantic basin remained very active by contributing almost one-third of the overall calendar year global ACE.”

Hurricane landfalls:

The graph below shows the number of land-falling hurricanes since 1970. The dark bars are category 1&2 hurricanes; the grey bars are hurricanes of category 3 and above.


See also:

Why Hurricanes Can’t Be Blamed On Global Warming

A Review of the state of Climate Science    See why reducing carbon dioxide emissions from burning fossil fuels will have no effect on global temperature.



What Global Surface Temperature is Ideal for Human Habitation?

The fake fear of climate change is the current boogeyman of our age. Some say we must eliminate some or all of our carbon dioxide (CO2) emissions or the Earth will become uninhabitable. They say we must limit global temperature to a maximum of 2°C. In articles referenced below I show why that is nonsense.

So, what is an ideal temperature? A new study led by Washington State University and published in the Journal of Astrobiology proposes an answer. This study examines exoplanets in the universe. The study is titled: In Search for a Planet Better than Earth: Top Contenders for a Superhabitable World. (Link to full study)

Paper Abstract:

The fact that Earth is teeming with life makes it appear odd to ask whether there could be other planets in our galaxy that may be even more suitable for life. Neglecting this possible class of “superhabitable” planets, however, could be considered anthropocentric and geocentric biases. Most important from the perspective of an observer searching for extrasolar life is that such a search might be executed most effectively with a focus on superhabitable planets instead of Earth-like planets. We argue that there could be regions of astrophysical parameter space of star-planet systems that could allow for planets to be even better for life than our Earth. We aim to identify those parameters and their optimal ranges, some of which are astrophysically motivated, whereas others are based on the varying habitability of the natural history of our planet. Some of these conditions are far from being observationally testable on planets outside the solar system. Still, we can distill a short list of 24 top contenders among the >4000 exoplanets known today that could be candidates for a superhabitable planet. In fact, we argue that, with regard to the search for extrasolar life, potentially superhabitable planets may deserve higher priority for follow-up observations than most Earth-like planets.

Bottom line: The best habitable planets will have a mean surface temperature about 5°C higher than on Earth.

My previous articles on the subject show why reducing CO2 emissions will be a multi-trillion dollar, futile exercise that will send us back to the dark ages :

Who Is Afraid Of Two Degrees Of Warming?

During the past 10,000 years (the Holocene), Earth experienced several cycles of warming and cooling which exceeded the mythical two degree limit. Civilizations thrived during the warm periods and had a harder time during cold periods.

Estimates Of Global Warming Reduction By Reducing CO2 Emissions

The latest talking point of progressive politicians, pundits, and activists is that America cannot afford not to spend trillions of dollars to “solve the climate crisis” because global warming is an existential threat. Even a complete elimination of U.S. greenhouse gas emissions would avert only 0.083°C to 0.173°C by year 2100. All climate policies by the US, China, the EU and the rest of the world, implemented from the early 2000s to 2030 and sustained through the century will likely reduce global temperature rise about 0.17°C in 2100.

A doubling of current atmospheric carbon dioxide will produce global warming of just over one degree Celsius. Since carbon dioxide is plant food, such a doubling would make the planet greener and food farming more productive.

See also:

A Review of the state of Climate Science

No Reduction of Atmospheric CO2 Due to Economic Slowdown

Carbon dioxide in the atmosphere is continuously measured by several observatories such as that at Mauna Loa, Hawaii. So far, the reduction of emissions due to the pandemic-induced economic slowdown has not resulted in a lower carbon dioxide content of the atmosphere.

As explained by Dr. Roy Spencer: “Atmospheric levels of carbon dioxide (CO2) continue to increase with no sign of the global economic slowdown in response to the spread of COVID-19. This is because the estimated reductions in CO2 emissions (around -11% globally during 2020) is too small a reduction to be noticed against a background of large natural variability. The reduction in economic activity would have to be 4 times larger than 11% to halt the rise in atmospheric CO2.” (Source) This means that carbon dioxide is an insignificant driver of global warming.  It also shows that reducing carbon dioxide emissions will have very little effect on global temperature.

See also: A Review of the state of Climate Science

New study shows that carbon dioxide is responsible for only seven percent of the greenhouse effect

Comments on the alleged megadrought

During the past few weeks, media have been hyping alarm about a new study  that claims that the Southwestern US is entering a megadrought and that the drought is made more severe by human-caused global warming. That claim is based on tree-ring analysis and computer modeling speculation.

Droughts have occurred due to natural cycles, but there is no physical evidence that carbon dioxide emissions play a significant role is controlling global temperature or precipitation. The new paper presents no evidence that alleged “human-caused” global warming is making the drought worse, it is just speculation. In fact, many droughts are associated with cooler periods.

Let’s put things in perspective. Here are the data for the past 1,200 years. It seems that “megadroughts” have occurred naturally, without any human influence.

These data show that the 20th century was wetter than normal. However, the next graph shows that there have been droughts. But, rather that entering a megadrought, we seem to be emerging from a dryer period according to NOAA.

The graph above comes from a 4-minute video posted by Tony Heller, on his “Real Climate Science” blog. This video destroys claims that the western United States is currently experiencing a nearly unprecedented megadrought. Video:



Evidence that CO2 emissions do not intensify the greenhouse effect

The Broken Greenhouse – Why CO2 is a minor player in global climate

A Review of the state of Climate Science

Drought in the West

The Scientific Case for Vacating the EPA’s Carbon Dioxide Endangerment Finding

This 24-page report by Patrick J. Michaels and Kevin D. Darayatna of the Competitive Enterprise Institute shows why the EPA’s “endangerment finding” was based on bad science and should be repealed.

Executive Summary

The U.S. Environmental Protection Agency’s (EPA) 2009 “Endangerment Finding” from carbon dioxide (CO2) and other greenhouse gases grants the agency a legal mandate that can have profound and far-reaching effects. The Finding is based largely on a Technical Support Document that relies heavily upon other mandated reports, the so-called National Assessments of global climate change impacts on the United States.

The extant Assessments at the time of the Endangerment Finding suffered from serious flaws. We document that using the climate models for the first Assessment, from 2000, provided less quantitative guidance than tables of random numbers—and that the chief scientist for that work knew of this problem.

All prospective climate impacts in the Endangerment Finding are generated by computer models that, with one exception, made systematic and dramatic errors over the climatically critical tropics. Best scientific practice would be to emphasize the working model, which has less warming in it than all of the others.

Instead, the EPA relied upon a community of wrong models.

New research compares what has been observed to what is forecast, and finds that warming in this century will be modest—near the lowest extreme of the prospective range given by the United Nations.

The previous administration justified its policy choices by calculating the Social Cost of Carbon [dioxide]. We interfaced their model with climate forecasts consistent with the observed history and enhanced the “fertilization” effect of increasing atmospheric concentrations of CO2. We find that making the warming and the vegetation response more consistent with real-world observations yields a negative cost under almost all modeled circumstances.

This constellation of unreliable models, poor scientific practice, and exaggerated estimates of the Social Cost of Carbon argue consistently and cogently for the EPA to reopen and then vacate its endangerment finding from carbon dioxide and other greenhouse gases.

The full document is available on the Competitive Enterprise Institute website at

See also: Dump EPA endangerment finding

Repeal the EPA endangerment finding

The Center for the Study of Carbon Dioxide and Global Change has send a 139-page petition to the Environmental Protection Agency (EPA) urging them to end their 2009 “endangerment finding”  for greenhouse gases due to lack of evidence.

The press release notes:

Over ten years have elapsed since the EPA Administrator made this judgment in its so-called CO2 Endangerment Finding. During that time a considerable amount of scientific research has been conducted on the potential impacts of rising greenhouses gases on humanity and the natural world. The additional knowledge obtained from such research and observations reveal quite clearly that rising greenhouse gases do not represent what EPA identified in 2009 to be a current or future threat to public welfare.

According to the Center’s Chairman, Dr. Craig Idso, who is the lead author of the petition, “multiple observations made over the past decade confirm the projected risks and adverse consequences of rising greenhouse gases are failing to materialize. The truth is, in stark contrast to the Endangerment Finding, CO2 emissions and fossil fuel use during the Modern Era have actually enhanced life and improved humanity’s standard of living. And they will likely continue to do so as more fossil fuels are utilized.”

The 139-page petition by the Center highlights multiple peer-reviewed scientific studies in support of this thesis. In particular, the petition shows (1) there is nothing unusual or unnatural about Earth’s current warmth or rate of warming, (2) historic and modern records of atmospheric CO2 and temperature violate established principles of causation, (3) model-based temperature projections since 1979 artificially inflate warming (compered to observations) by a factor of three, invalidating the models and all their ancillary claims associated with greenhouse gas-induced warming, and that (4) key adverse effects of greenhouse gas-induced warming,
including extreme weather events, temperature-induced mortality and sea level rise, are not occurring despite EPA predictions they should be worsening.

The petition also presents compelling evidence that CO2 emissions and fossil energy use provide critical benefits that act to enhance health and welfare for humanity and the natural world. According to Dr. Idso, “Without adequate supplies of low-cost centralized energy derived from fossil fuels, few, if any, of the major technological and innovative advancements of the past two centuries that have enhanced and prolonged human life could have occurred. Additionally, without the increased CO2 emissions from fossil fuel use over the past two centuries, Earth’s terrestrial biosphere would be nowhere near as vigorous or productive as it is today. Rather, it would be devoid of the growth-enhancing, water-saving and stress-alleviating benefits it has reaped in managed and unmanaged ecosystems from rising levels of atmospheric CO2 since the Industrial Revolution began.”

Download the entire petition here:

Click to access EPAPetitionCO2ScienceMarch2020.pdf

Just another climate extinction prediction scare from the UofA

Arizona Daily Star story Feb 19, 2020:

Print edition title: UA researchers: Warming could kill 3 million species in 50 years.

Online edition title: Arizona researchers predict extinction explosion in bleak new study

Star reporter Henry Brean writes: Human-caused climate change could drive close to a third of all plant and animal species worldwide to extinction in the next 50 years, according to a new study by researchers at the University of Arizona. Without a concerted effort to curb global warming, roughly 3 million species could be lost by 2070, warned UA professor John Wiens, who co-authored the study published last week in the Proceedings of the National Academy of Sciences. “What happens is up to us,” Wiens said. “If we do nothing, there’s going to be a massive loss of species. If we take action … we can cut that in half.”

See also: UofA press release

The paper:

Recent responses to climate change reveal the drivers of species extinction and survival

by Cristian Román-Palacios and John J. Wiens

The paper was published February 10, 2020 in PNAS (Proceedings of the National Academy of Sciences.) The PNAS paper is paywalled but you can read the full paper from Prof. Wiens’ website.


“Climate change may be a major threat to biodiversity in the next 100 years. Although there has been important work on mechanisms of decline in some species, it generally remains unclear which changes in climate actually cause extinctions, and how many species will likely be lost. Here, we identify the specific changes in climate that are associated with the widespread local extinctions that have already occurred. We then use this information to predict the extent of future biodiversity loss and to identify which processes may forestall extinction. We used data from surveys of 538 plant and animal species over time, 44% of which have already had local extinctions at one or more sites. We found that locations with local extinctions had larger and faster changes in hottest yearly temperatures than those without. Surprisingly, sites with local extinctions had significantly smaller changes in mean annual temperatures, despite the widespread use of mean annual temperatures as proxies for overall climate change. Based on their past rates of dispersal, we estimate that 57–70% of these 538 species will not disperse quickly enough to avoid extinction. However, we show that niche shifts appear to be far more important for avoiding extinction than dispersal, although most studies focus only on dispersal. Specifically, considering both dispersal and niche shifts, we project that only 16–30% of these 538 species may go extinct by 2070. Overall, our results help identify the specific climatic changes that cause extinction and the processes that may help species to survive.”

My take:

The paper claims that increases in yearly maximum temperatures is the most critical factor in extinctions, yet according to the paper, maximum temperature increased only 0.4°C at sites with previous extinctions versus 0.14°C at sites without extinction. It is hard to believe that such a small temperature rise would make a difference since over the past 10,000 years Earth experienced several warm-cool cycles of more than 2°C.

The species extinction prediction numbers are based upon temperature projections from climate models and extrapolated to guess possible future temperatures.


“The forcings that drive long-term climate change are not known with an accuracy sufficient to define future climate change.” — James Hansen, “Climate forcings in the Industrial era”, PNAS, Vol. 95, Issue 22, 12753-12758, October 27, 1998.


“In climate research and modeling, we should recognize that we are dealing with a coupled non-linear chaotic system, and therefore that the prediction of a specific future climate state is not possible.” — Final chapter, Third Assessment Report, IPCC.

The researchers speculate that past local extinctions in the areas studied may be related to climate change, but they present no physical evidence to support the speculation. There may have been other factors contributing to extinction.

Both Star reporter Henry Brean and researcher Wiens cite “human-caused” climate change by which I assume they mean carbon dioxide emissions. However, there is no physical evidence that shows carbon dioxide plays a significant role in controlling global temperature.

The researchers recommend: “…our results also suggest that successful implementation of the Paris Agreement targets (i.e., warming <1.5 °C by 2100) …could help reduce extinctions considerably, possibly to 16% or less by 2070. My, how politically correct.

Related articles:

A Review of the state of Climate Science

New study shows that carbon dioxide is responsible for only seven percent of the greenhouse effect

New Study shows that impact of carbon dioxide rising to 700 ppm is about 0.5°C

University of Arizona produces another global warming food scare

(A recent paper from the University of Arizona claims “Grasses across the globe may be unable to keep pace with a changing climate, threatening some of the world’s most critical food sources, according to new research by University of Arizona ecologists.”)

Impact of Paris climate accord and why Trump was right to dump it