Tag Archives: Michael E. Mann

Geoengineering: We should not play dice with the planet (The Hill)


Kim Cobb and Michael E. Mann, opinion contributors

10/12/21 11:30 AM EDT

The fate of the Biden administration’s agenda on climate remains uncertain, captive to today’s toxic atmosphere in Washington, DC. But the headlines of 2021 leave little in the way of ambiguity — the era of dangerous climate change is already upon us, in the form of wildfires, hurricanes, droughts and flooding that have upended lives across America. A recent UN report on climate is clear these impacts will worsen in the coming two decades if we fail to halt the continued accumulation of greenhouse gases in the atmosphere.

To avert disaster, we must chart a different climate course, beginning this year, to achieve steep emissions reductions this decade. Meeting this moment demands an all hands-on-deck approach. And no stone should be left unturned in our quest for meaningful options for decarbonizing our economy.

But while it is tempting to pin our hopes on future technology that might reduce the scope of future climate damages, we must pursue such strategies based on sound science, with a keen eye for potential false leads and dead ends. And we must not allow ourselves to be distracted from the task at hand — reducing fossil fuel emissions — by technofixes that at best, may not pan out, and at worst, may open the door to potentially disastrous unintended consequences. 

So-called “geoengineering,” the intentional manipulation of our planetary environment in a dubious effort to offset the warming from carbon pollution, is the poster child for such potentially dangerous gambits. As the threat of climate change becomes more apparent, an increasingly desperate public — and the policymakers that represent them — seem to be willing to entertain geoengineering schemes. And some prominent individuals, such as former Microsoft CEO Bill Gates, have been willing to use them to advocate for this risky path forward.  

The New York Times recently injected momentum into the push for geoengineering strategies with a recent op-ed by Harvard scientist and geoengineering advocate David Keith. Keith argues that even in a world where emissions cuts are quick enough and large enough to limit warming to 1.5 degrees Celsius by 2050, we would face centuries of elevated atmospheric CO2 concentrations and global temperatures combined with rising sea levels.

The solution proposed by geoengineering proponents? A combination of slow but steady CO2 removal factories (including Keith’s own for-profit company) and a quick-acting temperature fix — likened to a “band-aid” — delivered by a fleet of airplanes dumping vast quantities of chemicals into the upper atmosphere.

This latter scheme is sometimes called “solar geoengineering” or “solar radiation management,” but that’s really a euphemism for efforts to inject potentially harmful chemicals into the stratosphere with potentially disastrous side effects, including more widespread drought, reduced agricultural productivity, and unpredictable shifts in regional climate patterns. Solar geoengineering does nothing to slow the pace of ocean acidification, which will increase with emissions.

On top of that is the risk of “termination shock” (a scenario in which we suffer the cumulative warming from decades of increasing emissions in a matter of several years, should we abruptly end solar geoengineering efforts). Herein lies the moral hazard of this scheme: It could well be used to justify delays in reducing carbon emissions, addicting human civilization writ large to these dangerous regular chemical injections into the atmosphere. 

While this is the time to apply bold, creative thinking to accelerate progress toward climate stability, this is not the time to play fast and loose with the planet, in service of any agenda, be it political or scientific in nature. As the recent UN climate report makes clear, any emissions trajectory consistent with peak warming of 1.5 degrees Celsius by mid-century will pave the way for substantial drawdown of atmospheric CO2 thereafter. Such drawdown prevents further increases in surface temperatures once net emissions decline to zero, followed by global-scale cooling shortly after emissions go negative.

Natural carbon sinks — over land as well as the ocean — play a critical role in this scenario. They have sequestered half of our historic CO2 emissions, and are projected to continue to do so in coming decades. Their buffering capacity may be reduced with further warming, however, which is yet another reason to limit warming to 1.5 degrees Celsius this century. But if we are to achieve negative emissions this century — manifest as steady reductions of atmospheric CO2 concentrations — it will be because we reduce emissions below the level of uptake by natural carbon sinks. So, carbon removal technology trumpeted as a scalable solution to our emissions challenge is unlikely to make a meaningful dent in atmospheric CO2 concentrations.

As to the issue of climate reversibility, it’s naïve to think that we could reverse nearly two centuries of cumulative emissions and associated warming in a matter of decades. Nonetheless, the latest science tells us that surface warming responds immediately to reductions in carbon emissions. Land responds the fastest, so we can expect a rapid halt to the worsening of heatwaves, droughts, wildfires and floods once we reach net-zero emissions. Climate impacts tied to the ocean, such as marine heat waves and hurricanes, would respond somewhat more slowly. And the polar ice sheets may continue to lose mass and contribute to sea-level rise for centuries, but coastal communities can more easily adapt to sea-level rise if warming is limited to 1.5 degrees Celsius. 

While it’s appealing to think that a climate “band-aid” could protect us from the worst climate impacts, solar geoengineering is more like risky elective surgery than a preventative medicine. This supposed “climate fix” might very well be worse than the disease, drying the continents and reducing crop yields, and having potentially other unforeseen negative consequences. The notion that such an intervention might somehow aid the plight of the global poor seems misguided at best.

When considering how to advance climate justice in the world, it is critical to ask, “Who wins — and who loses?” in a geoengineered future. If the winners are petrostates and large corporations who, if history is any guide, will likely be granted preferred access to the planetary thermostat, and the losers are the global poor — who already suffer disproportionately from dirty fossil fuels and climate impacts — then we might simply be adding insult to injury.

To be clear, the world should continue to invest in research and development of science and technology that might hasten societal decarbonization and climate stabilization, and eventually the return to a cooler climate. But those technologies must be measured, in both efficacy and safety, against the least risky and most surefire path to a net-zero world: the path from a fossil fuel-driven to a clean energy-driven society.

Kim Cobb is the director of the Global Change Program at the Georgia Institute of Technology and professor in the School of Earth and Atmospheric Sciences. She was a lead author on the recent UN Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report. Follow her on Twitter: @coralsncaves

Michael E. Mann is distinguished professor of atmospheric science and director of the Earth System Science Center at Penn State University. He is author of the recently released book, “The New Climate War: The Fight to Take Back our Planet.” Follow him on Twitter: @MichaelEMann

Climate Change Brings a Flood of Hyperbole/The Climate Has a Gun (The Wall Street Journal)


Opinion | The Climate Has a Gun (The Wall Street Journal)

Those who dismiss risk of climate change often appeal to uncertainty, but they have it backward.

Aug. 17, 2021 1:14 pm ET 2 minutes

In “Climate Change Brings a Flood of Hyperbole” (op-ed, Aug. 11), Steven Koonin put himself in the unenviable position of playing down climate change precisely while we are experiencing unprecedented heat waves, storms, fires, droughts, and floods that exceed model-based expectations.

Mr. Koonin claims that regional projections are “meant to scare people.” But the paper he cites for support addresses the “unfolding of what may become catastrophic changes to Earth’s climate” and argues that “being able to anticipate what would otherwise be surprises in extreme weather and climate variations” requires better models. In other words, our current models cannot rule out a catastrophic future.

Model uncertainty is two-edged. If we’d been lucky, we’d be discovering that we overestimated the danger. But all indicators suggest the opposite. Those who dismiss climate risk often appeal to uncertainty, but they have it backward. Climate uncertainty is like not knowing how many shots Dirty Harry fired from his .44-caliber Magnum. Now that it’s pointed at our head, it’s dawning on us that we’ve probably miscalculated. By the time we’re sure, it’s too late. We’ve got to ask ourselves one question: Do we feel lucky? Well, do we?

Adj. Prof. Mark BosloughUniversity of New Mexico


Opinion | Climate Change Brings a Flood of Hyperbole (The Wall Street Journal)

Despite constant warnings of catastrophe, things aren’t anywhere near as dire as the media say.

Steven E. Koonin – Aug. 10, 2021 6:33 pm ET

The Intergovernmental Panel on Climate Change has issued its latest report assessing the state of the climate and projecting its future. As usual, the media and politicians are exaggerating and distorting the evidence in the report. They lament an allegedly broken climate and proclaim, yet again, that we are facing the “last, best chance” to save the planet from a hellish future. In fact, things aren’t—and won’t be—anywhere near as dire.

The new report, titled AR6, is almost 4,000 pages, written by several hundred government-nominated scientists over the past four years. It should command our attention, especially because this report will be a crucial element of the coming United Nations Climate Change Conference in Glasgow. Leaders from 196 countries will come together there in November, likely to adopt more-aggressive nonbinding pledges to reduce greenhouse-gas emissions.

Previous climate-assessment reports have misrepresented scientific research in the “conclusions” presented to policy makers and the media. The summary of the most recent U.S. government climate report, for instance, said heat waves across the U.S. have become more frequent since 1960, but neglected to mention that the body of the report shows they are no more common today than they were in 1900. Knowledgeable independent scientists need to scrutinize the latest U.N. report because of the major societal and economic disruptions that would take place on the way to a “net zero” world, including the elimination of fossil-fueled electricity, transportation and heat, as well as complete transformation of agricultural methods.

It is already easy to see things in this report that you almost certainly won’t learn from the general media coverage. Most important, the model muddle continues. We are repeatedly told “the models say.” But the complicated computer models used to project future temperature, rainfall and so on remain deficient. Some models are far more sensitive to greenhouse gases than others. Many also disagree on the baseline temperature for the Earth’s surface.

The latest models also don’t reproduce the global climate of the past. The models fail to explain why rapid global warming occurred from 1910 to 1940, when human influences on the climate were less significant. The report also presents an extensive “atlas” of future regional climates based on the models. Sounds authoritative. But two experts, Tim Palmer and Bjorn Stevens, write in the Proceedings of the National Academy of Sciences that the lack of detail in current modeling approaches makes them “not fit” to describe regional climate. The atlas is mainly meant to scare people.

Michael E. Mann: “My Comments on New National Academy Report on Geoengineering”

By Michael E. Mann on Thursday, March 25, 2021 – 12:26

Original text

The U.S. National Academy of Sciences has published a new report (“Reflecting Sunlight“) on the topic of Geoengineering (that is, the deliberate manipulation of the global Earth environment in an effort to offset the effects of human carbon pollution-caused climate change). While I am, in full disclosure, a member of the Academy, I offer the following comments in an entirely independent capacity:

Let me start by congratulating the authors on their comprehensive assessment of the science. It is solid as we would expect, since the author team and reviewers cover that well in their expertise. The science underlying geoengineering is the true remit of the study. Chris Field , the lead author, is a duly qualified person to lead the effort, and did a good job making sure that intricacies of the science are covered, including the substantial uncertainties and caveats when it comes to the potential environmental impacts of some of the riskier geoengineering strategies (i.e. stratosphere sulphate aerosol injection to block out sunlight).

I like the fact that there is a discussion of the importance of labels and terminology and how this can impact public perception. For example, the oft-used term “solar radiation management” is not favored by the report authors, as it can be misleading (we don’t have our hand on a dial that controls solar output). On the other hand, I think that the term they do chose to use “solar geoengineering”, is still potentially problematic, because it still implies we’re directly modify solar output—but that’s not the case. We’re talking about messing with Earth’s atmospheric chemistry, we’re not dialing down the sun, even though many of the modeling experiments assume that’s what we’re doing. It’s a bit of a bait and switch. Even the title of the report, “Reflecting Sunlight” falls victim to this biased framing.

In my recent book (“The New Climate War”), I quote one leading scientist on this:

“They don’t actually put aerosols in the atmosphere. They turn down the Sun to mimic geoengineering. You might think that is relatively unimportant . . . [but] controlling the Sun is effectively a perfect knob. We know almost precisely how a reduction in solar flux will project onto the energy balance of a planet. Aerosol-climate interactions are much more complex.”

I have a deeper and more substantive concern though, and it really is about the entire framing of the report. A report like this is as much about the policy message it conveys as it is about the scientific assessment, for it will be used immediately by policy advocates. And here I’m honestly troubled at the fodder it provides for mis-framing of the risks.

I recognize that the authors are dealing with a contentious and still much-debated topic, and it’s a challenge to represent the full range of views within the community, but the opening of the report itself, in my view, really puts a thumb on the scales. It falls victim to the moral hazard that I warn about in “The New Climate War” when it states, as justification for potentially considering implementing these geoengineering schemes:

But despite overwhelming evidence that the climate crisis is real and pressing, emissions of greenhouse gases continue to increase, with global emissions of fossil carbon dioxide rising 10.8 percent from 2010 through 2019. The total for 2020 is on track to decrease in response to decreased economic activity related to the COVID-19 pandemic. The pandemic is thus providing frustrating confirmation of the fact that the world has made little progress in separating economic activity from carbon dioxide emissions.

First of all, the discussion of carbon emissions reductions there is misleading. Emissions flattened in the years before the pandemic, and the International Energy Agency (IEA) specifically attributed that flattening to a decrease in carbon emissions globally in the power generation sector. These reductions continue on and contributed at least party to the 7% decrease in global emissions last year. We will certainly need policy interventions favoring further decarbonization to maintain that level of decrease year after year, but if we can do that, we remain on a path to limiting warming below dangerous levels (decent chance less than 1.5C and very good chance less than 2C) without resorting on very risky geoengineering schemes. It is a matter of political willpower, not technology–we have the technology now necessary to decarbonize our economy.

The authors are basically arguing that because carbon reductions haven’t been great enough (thanks to successful opposition by polluters and their advocates) we should consider geoengineering. That framing (unintentionally, I realize) provides precisely the crutch that polluters are looking for.

As I explain in the book:

A fundamental problem with geoengineering is that it presents what is known as a moral hazard, namely, a scenario in which one party (e.g., the fossil fuel industry) promotes actions that are risky for another party (e.g., the rest of us), but seemingly advantageous to itself. Geoengineering provides a potential crutch for beneficiaries of our continued dependence on fossil fuels. Why threaten our economy with draconian regulations on carbon when we have a cheap alternative? The two main problems with that argument are that (1) climate change poses a far greater threat to our economy than decarbonization, and (2) geoengineering is hardly cheap—it comes with great potential harm.

So, in short, this report is somewhat of a mixed bag. The scientific assessment and discussion is solid, and there is a discussion of uncertainties and caveats in the detailed report. But the spin in the opening falls victim to moral hazard and will provide fodder for geoengineering advocates to use in leveraging policy decision-making.

I am somewhat troubled by that.