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Debunked: The Global Dimming Dilemma

History | References

“Whatever way you look at it, we live on a dying planet. But dying does not actually mean dead. Despite all the damage that people have done to planet Earth in the last 100 or so years, the Earth can repair itself if we do the right things.” – John Kennedy

The Global Dimming Dilemma or Paradox
The topic of global dimming (a.k.a. aerosol masking effect) is often misunderstood. It has been used to promote climate change denial and doom [1] alike. It is a very real phenomenon, like its counter part global brightening (video). Right off, let’s be clear this is not a debunk of the global dimming or aerosol masking effect theory pioneered by James Hansen, PhD. This effect is now well-established in scientific research, including the well-known pan evaporation data which highly corroborates reasons to think aerosols cause global dimming. This debunk does not dispute these findings[2] nor does it debate the fact that pollution based aerosol dimming has a role to play in climate forcing.

Further, a new report contends that reducing aerosols that cause dimming may intensify heatwaves due to increases in mean warming, unless we can offset this with trees, biochar and other CO2 reducing agents as well as other last minute natural geoengineering techniques. This will be discussed further below.  But make no mistake, aerosol dimming presents a serious threat.

“Global dimming has devastating effects on the earth’s environment and living beings. The pollutants causing global dimming also lead to acid rain, smog and respiratory diseases in humans. [It also destroys and acidifies natural habitats for animal and plant life].⁠— Conserve Energy Future

However, large uncertainties surround the potential impacts of global dimming as well as brightening and other physics at work here. These effects can be direct as well as indirect meaning that the sum total effect is extremely difficult to map. Making any conclusions at this point indicates false logic and inference-observation confusion (i.e. jumping to conclusions). The top researchers in this field are still investigating what the impacts of these phenomena might be on average global temperatures (AGT), how global or regional these impacts are, and what mitigating strategies might effectively reduce these impacts. This is a matter of scientific inquiry much under investigation.  There are also inherent difficulties in modelling. This is an as yet understudied phenomena with many potential unknowns still being revealed.

For example, one study “Rethinking the lower bound on aerosol forcing” in the Journal of Climate, written by Prof. Bjorn Stevens, director at the Max Planck Institute for Meteorology and head of the department “The Atmosphere in the Earth System” presents a number of arguments as to why the cooling effect of aerosols is neither as strong nor as uncertain as has previously been thought. While some studies point to the potential under-reported impacts of dimming, many other studies show that cutting pollution won’t cause global warming spike. In short, the jury is still out on this research.

“Our study provides assurances that polluted air has a limited ability to prevent the atmosphere from heating up, in addition to being bad for people’s health. There is now one less excuse for us not to cut emissions of both air pollution and greenhouse gases, or we will continue to see that put people and the natural world in danger. In any case, a small temperature rise resulting from cutting is a price very much worth paying to prevent greater, long-term harm caused by greenhouse gases.” ⁠—

The tendency to oversimplify aspects of this theory for conjecture and convenience has led to problematic reporting and the fake news dilemma or paradox (also being called the “McPherson Paradox”) going around on the Internet that states “the aerosol masking effect will cook us with only a 35% reduction in aerosols. We have to keep burning coal until this is resolved.” This pseudoscience paradox is the topic of debunking addressed in this post.

In fact, there is no rationale by which we have to keep burning coal that is sane, rational or informed. Additionally, there is simply no excuse for encouraging continued burning of fossil fuels that is acceptable given our current situation. Anyone saying we must keep burning coal should be highly questioned at this point in history. In fact, the last time CO2 emissions were this high, modern humans didn’t even exist.

There is no question we must curtail dirty energy emissions from fossil fuels. The notion that we must keep polluting is a dangerous and utter absurdity guaranteed to line the pockets of fossil fuel robber barons. Voltaire said “those who can make us believe absurdities, can make us commit atrocities.” In this case, that would be failing to act to stop the climate and global air pollution crisis unfolding undeniably faster than expected everywhere on the planet.

Despite the many unknowns here, different types of deniers like to pretend that there are established certainties that will make solving global warming impossible. Further, they attempt to convince us it’s too late to do anything about it fomenting inaction and defeatism at the worst possible time. Let’s be clear it’s not too late.

These groups groups go so far as to continue to vociferously claim that this paradox makes it necessary to keep burning fossil fuels, which is of course agreeable to those profiting from this industry. They state in no uncertain terms that we will have to keep burning the fossil fuels that are killing us in order to keep temperatures down; temperatures they often claim are not rising in the first place ironically! Where are all the panglossians you might ask? Surely, some opposition to doomsday should present itself, but we are not there yet.

In this fake news and science report tilted “Shocker: Global warming may simply be an artifact of clean air laws,” presented by Watts Up With That, this kind of claim is presented. According to Wikipedia and others, Watts Up With That? (or WUWT) is a fairly well-known blog promoting climate change denial. Global dimming has become the subject of climate change denial campaigns everywhere, even in the White House. It is being used by unscrupulous entities as yet another reason to condone defeatism and inaction on climate issues in these circles.

“The Trump administration put out an environmental impact report a couple weeks ago and the content is, well, unexpected. While this particular White House is full of climate change deniers, the report boldly declares that global warming will be immensely devastating – so much so that it’s futile to try to do anything about it.” – CARE2

The Particle Puzzle: Dimming or Brightening?
Global dimming, known in scientific terms as the aerosol masking effect (video), is a theory being studied internationally. As previously mentioned, eminent climate scientist James Hansen, former Director of NASA Goddard, is among the first to have introduced this problem. In an epic program on this topic that aired on PBS titled Dimming the Sun, James Hansen estimated in 2006 that the so called “global dimming” produced by these aerosol particles is cooling the planet by more than a degree Celsius.

It was Hansen who also raised the initial concern that if we cut back on pollution, global warming could be compounded by this effect especially if we don’t handle this situation very carefully. Hansen first referred to this as a Faustian bargain back in 2006 stating that “aerosols have a cooling effect (by reducing solar heating of the ground) that depends on the rate that we pump aerosols into the air, because they fall out after about five days.” Additionally, there is a BBC Documentary, now a bit outdated, but considered a classic work on this topic and covers how pan evaporation data provides reasons to think aerosols cause dimming likely more regionally than globally. Again, this debunk does not dispute these findings[2]. Aerosols are clearly a factor in climate forcing. However, according to Hansen et al  “the amount [of dimming] is [as yet] uncertain because global aerosols and their effect on clouds are not measured accurately.”

Those at NASA Langley, furthering Hansen’s work, have also reported on this topic. However, no one at NASA has ever suggested that this is in any way a reason to keep burning fossil fuels! In the following video, Bruce Doddrige a NASA scientist, introduces uncertainties surrounding the study of our particulate atmosphere and at the end begins a discussion on how to reduce both global warming and global dimming smartly, using methods such as biochar. Others are now discussing iron salt aerosols and solar radiation management, discussed further on the SW Geoengineering Wiki.

According to the Wikipedia “an aerosol is a suspension of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are haze, particulate air pollutants and smoke.” It is known that anthropogenic aerosols, like those from factories, tailpipes, and fires negatively impact the environment and cause everything from warming, to cooling (what we are talking about here) to the acceleration of glacial melt around the globe by impacting albedo.

This is where it gets interesting. It turns out that some emissions, like black carbon from fossil fuels, can contribute to both warming and cooling (video) in different ways. This is really tricky stuff! Black carbon (BC) is a primary aerosol emitted directly at the source from incomplete combustion processes such as fossil fuel and biomass burning and therefore much atmospheric BC is of anthropogenic origin.

How Much Dimming Is There?
Most scientists are now proposing that the only known means by which humans can avoid climate catastrophe is the significant reduction of industrial activity and greenhouse gasses (GHGs) e.g. carbon dioxide (CO2).  It is proposed that we simultaneously reduce scattering aerosols e.g. sulfur dioxide (SO2) that impact cloud nucleation and formation. Quite simply, less cloud cover means less cooling.

It is understood that reducing emissions will alter solar irradiance and decrease the aerosol masking effect which is providing some cooling. How much is still in question. This cooling could be offsetting global warming by as much as 1°C according to some researchers. You will soon notice that there are at times different estimates given in different studies. On average, 1°C is currently the most widely cited by scientists. Recently a study found that the cooling effect of aerosols in cumulus and MSC clouds could be twice as high as previously thought. “Current global climate predictions do not correctly take into account the significant effects of aerosols on clouds on Earth’s overall energy balance.” says another article on this topic.


According to this Geophysical Research Letters study, “we show how cleaning up aerosols, predominantly sulfate, may add an additional half a degree (0.5°C) of global warming, with impacts that strengthen those from greenhouse gas warming.” Most scientists, journalists and researchers speaking on this say the amount of warming from dimming given in the most widely cited and published estimates is between 0.25 and 0.5°C. Various other estimates discuss that between 0.25-1.1°C of warming MIGHT BE induced if pollution is significantly reduced, unless we drawdown gradually that is. Studies do vary widely. There is no one answer. But the most common answer given is .5°C. This is reflected in the IPCC reporting on this as well which also gives .5°C. However, this is an ongoing matter of scientific investigation. In fact, Jasper Kirkby at CERN says ‘it is simply too soon to be so polarized over these matters because they are still being studied.’

Scientists are collecting and analyzing the data. Because scientists are working hard to share these models and their data online now, anyone can learn this stuff and examine the facts for themselves. There is a lot of good science happening. Check your sources and stay objective. Also check out all these great resources for further education on this topic at CERN’s CLOUD Project. This project is also exploring the connection between climate change and galactic cosmic rays. Yes, that’s right, galactic cosmic rays! In the following video with Dave Borlace of Just Have  A Think this is discussed.

According to Skeptical Science on this topic, “Henrik Svensmark has proposed that galactic cosmic rays (GCRs) could exert significant influence over global temperatures (Svensmark 1998).  The theory goes that the solar magnetic field deflects GCRs, which are capable of seeding cloud formation on Earth.  So if the solar magnetic field were to increase, fewer GCRs would reach Earth, seeding fewer low-level clouds, which are strongly reflective.  Thus an increased solar magnetic field can indirectly decrease the Earth’s albedo (reflectivity), causing the planet to warm.  Therefore, in order for this theory to be plausible, all four of the following requirements must be true.”

This topic is challenging to say the least. Still it is necessary for us to study these topics if we are to be members of an informed society. We also have to understand that science never stops questioning and we must be able to deal with these uncertainties without jumping to conclusions. According to Jasper Kirkby, Particle Physicist at CERN, ‘the area of aerosols is very poorly understood, yet this does not mean we don’t understand the big picture phenomena involved.’

We know that global warming and global dimming are indeed happening, and faster than expected. Also, we have many proposals for solutions. Sadly, this doesn’t mean we are using what we know and this is a constant reminder that we are living in a time when genuine science and scientists are routinely marginalized and undermined by prevalent thinking errors, confusion, fake news, and denial campaigns.

NASA has created a map showing global aerosol distribution for further modelling. This will allow scientists and the public to visualize the movement and impacts of these dangerous particles. The research and data are still coming in. Scientists must continually investigate the extent and knock-on effects of these large scale phenomena.

“The CLOUD project at CERN is essentially just getting started. Its preliminary findings will help aerosol modelers, and hopefully it will continue to provide useful results…But there’s no such thing as too debunked when it comes to myths about climate change, and there’s little chance this will be the last time [that this] will be trotted out to claim that we don’t need to reduce greenhouse gas emissions.” – Skeptical Science

Deniers of Many Stripes
Deniers exaggerate the unknowns related to the effects of aerosols and claim that if we were to stop polluting suddenly, which is unlikely in any case, global average temperatures would shoot up and fast. Catastrophists have made the claim that this is an unsolvable paradox and further, that if we were to stop polluting today by just 35% we would experience an immediate and deadly 1.2-5°C temperature rise in as little as a few weeks time, citing this study by Levy et al.

They claim in no uncertain terms that this fictional temperature rise will terminate all life on the planet and drive us extinct overnight. They weave fact and fiction together so seamlessly that some have now begun to identify this as a new genre of “extinction fantasy.” Although in an era of rabid fake news, this distinction is not clearly made and many begin to take these scenarios very seriously.

Upon closer inspection, this study by Levy et al actually says that these effects are still relatively uncertain and would likely take until at least the end the 21st century, completely invalidating all these premature warnings about a proposed sudden spike in temperatures. Additionally, this study is careful to state there are enormous unknowns “regarding the role of aerosols in climate [and] the actual magnitude of the aerosol effect.” This means that the effects are also known to be regional in nature and that they don’t act all at once globally as these doomers erroneously imply.

According to climate scientist Professor James Renwick, from Victoria University, some doomers have claimed that “cutting aerosol pollution to zero (as would happen when and if industrial society falls over) will unmask another 2.5°C of warming. This is a factor of ten too large, as the actual amount would be around 0.25°C by current best estimates (see figure 10.5).” This shows a clear exaggeration of the data.

Climatologist Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies, in a Twitter thread commenting on the new aerosol research further says, “you cannot assume that net zero CO2 emissions must also imply zero anthropogenic aerosol emissions. As a result, he added, it’s important to note that anthropogenic aerosols will not suddenly disappear and make global warming much worse.”

Still, doomsday scenario writers overstate the unknowns to make the claim that a reduction in global dimming portends an immediate loss of habitat for human animals with human extinction immediately to follow. Based on these biased interpretations they warn copiously that we have to keep polluting or we will go extinct, proffering the exact opposite of the truth.

Deniers and doomers exploit speculative areas of the research for their own ends. They deliberately oversimplify and exaggerate this issue to make it fit their arguments so that they can conclude that if we keep emitting industrial pollution we are creating the conditions for extinction, and, at the same time, if we stop emitting we are creating the conditions for extinction. They refer to this as a paradox, but this is only a paradox of black and white thinking. By definition, it is not a paradox (video).

Additionally, this fictional massive rise of 1.2-5°C in temperature suggested by doomist pseudoscience as the result of reduced aerosol pollution is a completely absurd number“(video) says Paul Beckwith, Climate System Scientist, who reiterates that it is more likely to be about 0.5°C. This exaggerated reporting continues to be responsible for repeated fake news warnings from deniers and doomers who want us to believe that doing anything about it is futile and doing nothing is best. This is a false flag and very bad advice, and it should be treated as such.

It is true that our continued reluctance to reduce carbon emissions fast enough makes the two goals of eliminating air pollution and limiting global warming seem mutually exclusive. This means the real dilemma is, in effect, caused by our inertia and failure to act. It is also because of the continued refusal to discuss what’s really going on or the actual solutions in favor of keeping business as usual (BAU) going at all costs.

Global Brightening
According to the EPA global dimming has already been reversed in North America and Europe. Sulfate aerosols declined with the Clean Air Act (1970) in the United States and similar policies in Europe. The EPA reports that from 1970 to 2005, total emissions of the six principal air pollutants dropped by 53% in the US.

In this article from Forbes titled How Can We Stop Global Dimming?, this is summed up as follows: “since the 1980s, pollution controls have substantially reduced air pollution which was one of the major contributors to dimming. Airplane contrails are still around providing some dimming. Places like Poland and Texas are still burning coal by the freight train load and doing their bit to keep the skies dim. But mostly the developed world has either ditched coal or substantially restricted the crap that it puts into the air.”

This means we have already undergone some the worst effects mentioned by deniers. Now we are actually on a brightening (video) trend. According to Wikipedia “this switch from a global dimming trend to a brightening trend happened just as global aerosol levels started to decline (roughly 1990). Analysis of recent data reveals that the surface of the planet has brightened by about 4% in the past decade. The brightening trend is corroborated by other data, including satellite analyses.”

Removing the Mask
The next time someone tells you global dimming means extinction, remind them that we are actually in global brightening, which essentially means the mask is off. Sometimes this stuff is really counter intuitive and we must also guard against jumping to pseudoscience conclusions as with NTHE claims.

According to Dr. David A. McKay, currently a Postdoctoral Researcher at Stockholm Resilience Centre (Stockholm University) “while the total removal of human-made aerosols would lead to a short-term warming of ~0.4oC (and ~0.6oC by 2100), an abrupt end to all aerosol emissions at once is very unlikely. Decarbonisation will take decades, and aerosols come from a wide variety of sources beyond just the heaviest emitting power stations. Even a challenging target of halving aerosol emissions in the next couple of decades would only lead to ~0.2oC of warming – the equivalent of around a decade more of the current warming trend – which is preferable to carrying on emitting carbon indefinitely instead and is less likely to trigger any tipping points.”

Another study discusses how the relative importance of aerosols, clouds, and aerosol-cloud interactions may differ depending on region and pollution level. This means global brightening or dimming are not actually global, but regional effects at least initially. Over time, it is important to note that there is further mixing of all  emissions in the atmosphere which may have yet another net effect not yet calculated. These conclusions are in line with independent long-term observations of sunshine duration, diurnal temperature range, pan evaporation, and, more recently, satellite-derived estimates. However, as the study indicates, current climate models do not simulate these changes very well.

We Must Reduce Both Global Warming and Aerosol Pollution
Even though the current trend is toward brightening, we still have to contend with aerosol pollution and the some 2-3% of dimming we are still experiencing. The rate of dimming varies around the world, but is estimated at around 2–3% on average per decade. So let’s actually talk about the many proposed mitigations for the global dimming phenomena.

The first thing we need to do is get our emissions down. Some are strongly suggesting that we halt fossil fuel expansion and subsidies by the 2020’s, like the Club of Rome. We need this kind of aggressive approach to make change happen in the time required. Next, because, as many have duly noted we just aren’t doing that, we likely have to consider some necessary evils. No one wants to further disrupt the earth’s already badly disturbed systems.

However, because we have already unbalanced the system, we must now consider options like geoengineering. Geoengineering is often a feared concept. But it doesn’t have to be. In fact, it is recommended that we start to drawdown on emissions right away while applying the natural geoengineering techniques discussed below and beyond. It is certain that we must clean up our act and now.

“Global dimming has devastating effects on the earth’s environment and living beings. The pollutants causing global dimming also lead to acid rain, smog and respiratory diseases in humans….it is going to be important that emission of both greenhouse gases and particulate matter should be reduced simultaneously [while adding exudates from foliage, etc.]. This will balance out both the phenomena [as we begin to gradually drawdown].” – Conserve Energy Future

Natural Geoengineering Means We Don’t Have to Fear Clean Air
Trees are known to produce natural aerosol particles that make up what is known to be the largest river on earth in the sky (video) by seeding clouds, creating cloud cover and ultimately producing rain. Tall prairie grass is also now being discussed as just as effective as trees. Vegetation and rewilding are well-known solution that are often ignored.

Reforestation (afforestation) is always a good idea. It is also a form of natural, non-toxic and safe geoengineering we don’t have to fear. Not all geoengineering involves techno-fantasy and high stakes risks with toxic components. In this case, we have the technology and it’s called a tree! Tragically, we are cutting them down for profit and industry faster than they can grow. In short, we must end limitless growth economy before it ends us.

“Nature produces abundant particles without any pollution…the trees can do it with zero pollution.” Jasper Kirkby, CERN

Recent studies reveal that the findings from the several experiments show that trees release molecules that contribute to cloud seeding. According to these studies, it was thought that the pollutant Sulfuric acid is required for a particular cloud formation. Sulphur dioxide (SO2) dissolves in the water vapour in clouds to form form dilute sulphurous acid (H2SO3). But these studies are showing that aerosols can form and grow to the size needed to seed a cloud from the molecules naturally emitted by trees, without requiring Sulfuric acid.

“What it means is, we don’t have to fear clean air.” – Bjorn Stevens, Max Plank Institute

Bjorn Stevens, atmospheric scientist, said that “the findings of the experiments have another important implication regarding the public’s perception of global warming and clean air. Some scientists believe that measures such as ridding the atmosphere of Sulfur dioxide by limiting coal plant processes could remove some of the beneficial cooling effect of clouds, and therefore boost global warming. However, upon knowing that trees can do the cloud seeding job themselves, this will be less of a concern today. ” New studies continue to emerge to date extolling the virtues of planting trees to mitigate climate change.

Explore Further >>
There are even more natural geoengineering topics under debate and being discussed on the SW Geoengineering Page.

Did You Know The Plankton Make The Clouds?
Did you know that Plankton have a large role in cloud production? Environmental Scientist and Climate Writer, Guy Lane says “the Plankton Meditation is a guided meditation that helps you come to terms with fundamental ecological truths that are often overlooked.”


It’s Not Too Late
Despite this strong, certain and constant claim that it’s too late to act by the Trump administration and other deniers, it is extremely important to be aware that there are many valiant, credentialed climate scientists working on solving this problem and they are saying that it’s not too late. It is certain that anyone saying that it is necessary to keep polluting to avoid this disaster is promoting a fallacy fraught with thinking errors resulting in confirmation bias.

“The evidence that climate change is a serious problem that we must contend with now, is overwhelming on its own. There is no need to overstate the evidence, particularly when it feeds a paralyzing narrative of doom and hopelessness. – Michael Mann

The additional claim that this dilemma will be the end of humanity is paving the way for further adoption by powerful fossil fuel interests (video) and deniers to argue that they might as well “drill baby drill” because it’s too late to do anything about it. Drawing this premature conclusion toward an unquestionable certain extinction clearly leads to inaction, inertia, and defeatism. It also does an extreme disservice to those working to mitigate this crisis. It also halts action from individuals as they assume nothing can be done and fail to act.

Dr. Michael Mann and others have published a paper looking at summertime extreme weather patterns in future scenarios of global warming. Mann says that “while climate change will initially exacerbate extreme weather, it is possible that reduction of aerosols from atmospheric pollution could counteract this effect.”

Michael Mann also recently said “by mid-century, once the aerosols are no longer produced, greenhouse warming once more dominates . (…)The future is still very much in our hands when it comes to dangerous and damaging summer extremes. It’s simply a matter of our willpower to transition quickly from to renewable energy.” Read more on weather extremes still within our grasp.

David Suzuki (video) recently said, to paraphrase, ‘it doesn’t look like we have a chance of staying under 2˚C. But those saying it’s already too late need to go away, and right now.’ Scientists do recognize that the situation is dire and an emergency. Paul Beckwith, Climate Systems Scientist of the University of Ottawa has said we need to declare a global climate emergency and now. But none of these researchers advise quitting and going home. According, to eminent climate scientist, Michael Mann “‘we can still prevent many of the worst impacts of climate change from playing out”. There’s a lot each individual can do. Get started today.

It Is Now or Never
The situation is serious, but according to many scientists it is also solvable. Rewilding, reforestation, and other natural solutions remain the ideal. If we can get out of the way of nature, stop polluting and employ some natural geoengineering strategies to aid this process we might find way out of this very real predicament that has us on course for the sixth mass extinction, now scientific consensus.

“It’s frightening but true: Our planet is now in the midst of its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years. We’re currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago. Although extinction is a natural phenomenon, it occurs at a natural “background” rate of about one to five species per year. Scientists estimate we’re now losing species at 1,000 to 10,000 times the background rate, with literally dozens going extinct every day. It could be a scary future indeed, with as many as 30 to 50 percent of all species possibly heading toward extinction by mid-century.” – The Extinction Crisis

Anyone making predictions of absolute certainty about an inevitable future should possess a crystal ball. Otherwise, we can easily fall prey to self-fulfilling prophecies of denialism and certain doom while failing to notice all the possibilities still in front of us.

“Even if there is no hope, we have to do something. Not having hope is not an excuse for not doing anything. But the thing we need more than hope is action, because once there is action there is hope.” – Greta Thunberg (video)

We have entered the Anthropocene, and we do have some say as much as 130 feet of sea level rise already baked in even if we stop polluting today. We are facing a crisis. We need to talk about what can be done as much as we talk about what can’t be done. Simply put, we cannot afford to get confused by denialism, defeatism or doom now. We only have a short window to act and failure is not an option.

Plant a tree and heal the biosphere: Yes We Can!


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  • 1:25 pm Aug. 5, 2019 – Shani Cairns – (Updated intro paragraphs with even more new study findings and clarified opening remarks, added links to several new studies).
  • 3:35 pm Aug. 4, 2019 – Shani Cairns – (Updated intro paragraphs with new study findings and clarified opening remarks. Re-wrote and updated several sections with the latest information).
  • 5:45 pm Jan. 21, 2019 – Shani Cairns – (Added new footnotes section and anchors).
  • 2:30 pm Jan. 20, 2019 – Shani Cairns – (Added new history/references short-codes and sections. Updated content. Linked to new article regarding aerosol releases double what previously thought).
  • 11:30 am Jan. 1, 2019 – Charles Gregoire – (Fixed a few more offsite links to open in new tabs. Put it up on the Home page new content slider in the number two spot. Updated the title).
  • 6:00 pm Dec. 31, 2018 – Charles Gregoire – (Completed another of several editorial reviews).
  • 1:15 pm Dec. 26, 2018 – Shani Cairns – (Updated content and added NASA atmospheric aerosols explanatory lecture video and NASA aerosol distribution map links. Clarified some terminology and introductory matters).
  • 3:15 pm Dec. 23, 2018 – Shani Cairns – (Wrote and published working article post of “Debunked: Global Dimming” content).
  • 3:00 pm Dec. 23, 2018 – Shani Cairns – (Added “Debunked: Global Dimming” and associated “History” page. This is to address the dilemma of global dimming that has recently been called a paradox and impossible to solve. It is being used by deniers and doomers alike to say that climate change can’t be solved and thus we should continue our path of inaction).

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[1] Usage of the Term Gloom-and-Doomers

Doomers, sometimes called gloom-and-doomers, and catastrophists are trending terms in climate science. They are used here in a descriptive and not a pejorative sense, to refer to those who see no way out of the current predicament and have begun to argue that any action to remediate the situation is already futile as we are headed for inevitable catastrophe. In other words, they are spreading the word that it is too late and that near-term extinction is inevitable within the next decade.

Many in the climate research community have been suffering with increased depression and anxiety due to the sheer mass of negative, extremely dire data they are confronted with on a daily basis. However, this psychological impact should be distinguished from this term doomer as a separate issue altogether not addressed in this article.

In popular culture some are now distinguishing between a near-term human extinction (NTHE) doomer and a gloomer as well. It is worth noting that scientists commonly refer to immediate, unpredictable changes as “abrupt,” so this term, NTHE, is not academically preferred terminology and has begun to also signal fake news and science reports. (Back)

[2] Purpose of This Debunk

Please note that this is a debunk of the global dimming “dilemma” or “paradox” pseudoscience theory (see NTHE) and how it is handled in the media, thus the title Debunked: Global Dimming Dilemma. This debunk addresses the dilemma/paradox and how it often wrongly presented to mean the certain end of all life on the planet. Please be clear, this is not a debunk of the global dimming or aerosol masking effect as a theory. Make no mistake global dimming is a real, valid and well established phenomena.

The purpose is to educate on the topic of the global dimming theory, while distinguishing between science facts versus science fiction. This is about debunking deniers and doomers using this effect to claim we must keep burning fossil fuels because first, its too late to stop polluting now because if we stop then we are guaranteed to lose our cool (not so, if we do the right thing) and second, it’s futile to stop burning the planet because global dimming is already too wide spread.

Further this debunk intends to discuss the complexities and much misinterpreted unknowns, to highlight the potential solutions never addressed by deniers (trees), and finally to highlight that this dilemma is being exaggerated for the purposes of those with another agenda. The primary counter points are can be summarized as follows:

1) It is obvious to all in the scientific community and beyond that we cannot cannot afford anymore warming, thus the 0.5-1.1°C of warming anticipated from the global dimming effect must be offset by gradual drawdown solutions which produce natural aerosol effects such as afforestation, plankton cloud generation, and many more listed on the SW Geoengineering Wiki. These solutions are never discussed by deniers or doomers.

2) Many of the effects of global dimming are as yet unknowns. The impacts of global dimming are not actually always “global” and scientists are just starting to uncover this noting their regional effects differ widely. This is a  field in its infancy.

3) We are actually experiencing global brightening since the 1990’s, a trend never discussed by deniers.

4) We don’t have to fear clean air. It’s simple, plant a tree. And;

5) Claiming that we must keep burning fossil fuels because otherwise we will lose our cool, is not cool.


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Note: This page, as with many wiki pages, is a work in progress. It aims to debunk erroneous notions related to the notion of global dimming as a “paradox” that has been circulating in fake news online. It does not debunk the global dimming effect itself.

3 Replies to “Debunked: Global Dimming Dilemma”

  1. Good job on a tough topic. You really walked the line here and it’s a hard edge.

    To me it seems that to do NOTHING, as advised by these doomers and deniers, while something wrong is occurring, is symptomatic of the current age. Maybe we need more data, or more iPhone pictures of suffering? To do nothing is neither human, nor civilized.

    It seems like the slew of nutters, doomers, and deniers just keeps coming. I am so glad David Suzuki told them to shut up this week. It’s about time all scientists did. That guy reeks of a Frère Jacques mentality, while begging some “material goods” donations. If he and his flock want to be a monks, they should shut up and be monks.

    Deniers and doomers are going after the gullible to science. We must make ourselves impervious to science by knowing it better and knowing it’s limitations – we must avoid making broad sweeping arguments of certainty from unknowns, which seems to be a thing for doomers.

    Meanwhile, lets make an effort to change the toxic paradigm.


  2. Wow, this really impressed me and made me think. We really need to remember that we are experiencing global brightening as pointed out in this educational page. Why is no one talking about this? Yet, so many are saying we can’t stop burning fossil fuels because of this global dimming dilemma. They are also saying it’s too late to plant trees tragically.

    There’s still plenty of pollution coming at us from many sources, even if we stop burning coal. There are also more particles from increased wildfires and volcanic activity. Also, there will be multi-million tons of more pollution from deregulation of auto emissions under Trump. To advocate increased pollution and GHG which will increase the rate of meltdown of the Arctic methane deposits, permafrost melt and heating oceans is pure madness if you ask me.

    Too many people are talking about global dimming doom theories and not studying the phenomena carefully. Everyone it seems has suddenly become a scientist. Meanwhile the scientists studying the issue note it’s an unknown in how it will play out. Furthermore, there are spatial and geographic characteristics to global dimming you pointed out here very nicely. It will have different manifestations throughout the globe. And to single out one pollutant when there is thousands of them makes no sense either.

    So many have been hoodwinked by the hidden neoliberal agenda of the most prevalent global death cult in the world (Trump et al) and are saying we can’t stop burning fossil fuels because then we’ll have an immediate 1°C temperature rise resulting in what pseudoscience is now referring to as near term human extinction – a concept which seems to ironically feed the largest fossil fuel oligarchs on the planet while claiming to care for the environment. It’s definitely time to debunk this. Good job!

  3. Yes, good debunk of the dimming dilemma or paradox … Here’s even more math the proves it too.

    The Absurd Claim That We Must Keep Burning Fossil Fuels
    Let’s explain the pseudoscience of the so-called “McPherson paradox” (which isn’t any paradox at all). The paradox claims that if we stop burning coal, (especially) and “dirty” diesel and other fossil fuels to a lesser extent, we will remove enough air pollution, if industry also cleans up in general, to cause global average temperatures to spike and warming to increase so quickly that is will bring collapse of civilization in short order.  So, let’s look at two optional approaches based on the 2018 burning rates to keep this example simple.

    Option 1: Business As Usual (BAU)
    (This means we keep burning coal/oil/gas at the 2018 rate of +0.81 w/m**2). +0.80 w/m**2 is the extra warming over the next 20 years if 2018 coal/oil/gas is burned each year, so:

    1.61 w/m2 is the total warming over the next 20 years with continued burning.
    2.41 w/m2 is the total warming over the next 40 years with continued burning.
    3.21 w/m**2 is the total warming over the next 60 years with continued burning.

    Option 2: An As Yet Undetermined Alternative Approach
    (This would be if we cut all coal/oil/gas is burning to zero over 20 years, currently +0.81 w/m2).

    +0.40 w/m2 is the extra warming over the next 20 years if coal/oil/gas burning is reduced to zero over 20 years.
    +0.86 w/m**2 is the extra warming over the next 20 years because the air is getting cleaner due to less coal/oil/gas burning so more “sunlight” gets through. (Note: his one-shot one-time-only large extra warming lump of +0.86 w/m**2 is the amount of the so-called, stupidly-named “McPherson paradox”)

    2.07 w/m2 is the total warming over the next 20 years with coal/oil/gas burning reduced to zero. 2.07 w/m2 is the total warming over the next 40 years with coal/oil/gas burning reduced to zero.. 2.07 w/m**2 is the total warming over the next 60 years with coal/oil/gas burning reduced to zero. This would need to consider the climate lag.

    Note: From this experiment above, it shows there would be 30% MORE warming over the next 20 years if coal/oil/gas burning is reduced to zero over 20 years than if 2018 coal/oil/gas is burned each year (as an example). So, it will +0.52 degrees over the next 20 years instead of +0.40 degrees, an extra +0.12 degrees due to reducing coal/oil/gas burning over 20 years.

    So, there’s NO paradox because at 32 years from now the cleaner air has finished most of its warming and there’s no coal/oil/gas burning so the warming is tapering rapidly down to zero if the sensible choice is made but continues relentlessly upward if the poor choice of continuing the burning of coal/oil/gas is made. The same sort of ratios apply with the actual likely emissions rates except, obviously, the faster the rate of burning turns out to be then the more benefit is accrued by disregarding the  “McPherson paradox” and cutting the burning rate immediately because that faster reduction reduces both sets of numbers above but reduces the 1st set far more than the 2nd set.

    To summarize this paradox implies that if we keep burning coal the radiative forcing of the Earth (in accumulated w/m**2 of heating power flux) is 1.61 2.07 over the next 20 years 2.41 2.07 over the next 40 years 3.21 2.07 over the next 60 years. It’s not a paradox because anyone can clearly see that the continuation of BAU and carbon burning rapidly leads to catastrophic warming as the decades go by, but stopping all carbon pollution over the next 20 years does not.

    It would be absurd not to stop BAU and end Fossil Fuel + dirty energy + dirty money ASAP.

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