One Good Reason Why the Left Should Give Geoengineering a Second Look – Joshua B. Horton

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Geoengineering, the idea of deliberate, large-scale intervention in the Earth’s climate system to help counteract the effects of global warming, has been in the news again. In February, the National Academies of Science released two major reports on geoengineering, one on carbon dioxide removal technologies (to draw down carbon dioxide from the atmosphere and hence reduce the greenhouse effect) and the other on “albedo modification” or solar radiation management technologies (to reflect a fraction of sunlight back to space and thereby cool the planet). These reports, and particularly their calls for more research into both methods, provoked what has become a predictable outcry from segments of the political left. Friends of the Earth decried geoengineering as “unjust, unproven and risky.” Rachel Smolker and Almuth Ernsting of Biofuelwatch agreed, repeating a claim commonly made by opponents of research on geoengineering: “the negative effects of different types of geoengineering would likely be felt most dramatically in the global South.”

Setting aside other objections to geoengineering, many of which are valid and must be thoroughly weighed and considered, it is past time to challenge the assertion that geoengineering, in particular solar geoengineering, would disproportionately harm the world’s poorest and most vulnerable populations. In fact, the available evidence suggests that the exact opposite may be true: solar geoengineering would likely disproportionately benefit developing countries. Moreover, it may be uniquely capable of doing so.

The starting point is the uncontroversial observation that climate change will almost certainly harm the world’s poorest most of all, for the simple reason that the most disadvantaged by definition have the fewest resources available to manage and adapt to negative climate impacts. The poor are least able to protect themselves from heat waves, and limited accessibility to water makes populations in many developing countries especially vulnerable to droughts. These populations are also vulnerable to flooding associated with heavier rainstorms. Strong evidence suggests that crops are easily damaged by high temperatures during their germination season, and that warming over the last three decades has already reduced crop yields. These losses will accelerate sharply with warming, and they will strike hardest in the global South. Marginalized populations tend to depend more directly on local ecosystems for subsistence and survival, so ecosystem stress is likely to affect them more immediately than others. Rising sea levels pose special risks for poor coastal communities, whose relative lack of mobility makes them particularly exposed to the effects of inundation. And of course many of these climatic phenomena are likely to be geographically concentrated in the tropics, where developing countries are also concentrated.

The available evidence suggests that solar geoengineering would likely disproportionately benefit developing countries.

Mitigation and adaptation are essential to addressing climate change over the long term, but over the short to medium term they will almost certainly be insufficient to protect the world’s poorest from the worst effects of global warming. According to the Intergovernmental Panel on Climate Change, inertia in the climate system means that even if the world were to miraculously stop all emissions of carbon dioxide tomorrow, we would still be committed to at least .6° C (1.1° F) of warming. In reality, emissions are growing. We are currently on a trajectory toward 1° to 2° C (1.8° to 3.6° F) of warming by mid-century. And there are real limits to our ability to adapt to climate change; for example, temperature thresholds exist above which staple crops like maize, rice, and wheat simply will not grow.

The unpleasant reality is that mitigation and adaptation will be incapable of fully contending with the most severe impacts of climate change over the coming decades. Indeed, only one possible policy tool looks to be capable of effectively reducing near-term climate risks: solar geoengineering. Solar geoengineering, for instance via dispersal of a small amount of sulfate particles into the upper atmosphere, appears capable of moderating global temperature increases within months to years. There would be side effects, and the fundamental source of climate change, carbon emissions, would be left unaddressed, but as of now, no other serious possibility exists for attenuating near-term climate damages. And to repeat, it is the world’s poorest and most vulnerable people who are likely to suffer the bulk of these damages.

The unpleasant reality is that mitigation and adaptation will be incapable of fully contending with the most severe impacts of climate change over the coming decades.

So why would critics assert that geoengineering would hurt, rather than help, the global South? The answer is not entirely clear, but part of it is undoubtedly related to the nature of the computer modeling work that has constituted most scientific research on solar geoengineering to date. This work has generally involved simulating very large geoengineering interventions in order to produce very strong signals of the climatic effects. The deliberately exaggerated nature of some early simulations produced exaggerated modeling results, including significant changes in regional rainfall such as disruptions to Asian and African monsoons. While these results were troubling and stirred intense debate, subsequent, more refined, and more realistic model simulations have yielded much less dramatic side effects. Indeed, recent research performed by the world’s leading geoengineering modeling collaborative indicates that all regions of the world would be better off (closer to preindustrial conditions) with solar geoengineering than without.

While a more realistic implementation of geoengineering would still inevitably entail costs, there is a reasonable chance that these would be more than offset by benefits in terms of reduced climate impacts of the sort described above. How the ledger is likely to balance out globally, and particularly for the global South, is unknown, yet that is precisely the reason why more research on solar geoengineering is so urgently needed. Acknowledging this leads to a recognition of the profound inconsistency exhibited by many of geoengineering’s most ardent critics, who proclaim deep commitments to social justice but resist any attempt to promote research into the only policy tool that appears capable of alleviating some of the suffering otherwise certain to befall the world’s poorest and most marginalized peoples. If they are truly committed to social justice, these critics ought to voice support for research on those technologies that appear uniquely suited to assist those who are most vulnerable to climate change.

33b4001Joshua Horton is a Postdoctoral Research Fellow with the Science, Technology, and Public Policy Program at the Belfer Center for Science and International Affairs, Harvard Kennedy School.



The Forum for Climate Engineering Assessment does not necessarily endorse the ideas contained in this or any other guest post. Our aim is to provide a space for the expression of a range of perspectives on climate engineering.

  • Duncan McLaren

    Thanks for your post Joshua. As I think you know, I believe the justice question is a
    critical one in consideration of geoengineering. Unfortunately, at the risk of a terrible pun, I’m not sure you’ve done it justice here …

    I do not disagree with your central conclusion that more research into geoengineering is merited, given the very slow progress made in mitigation, and the
    slow rate at which climate systems could respond to accelerated action. There are at least three further issues though:

    First, even if you think it can be managed, you do need to explain why a greater focus on SRM geoengineering would not significantly deter or delay action on mitigation or adaptation (the so-called moral hazard problem). If advocates of SRM research don’t even acknowledge the problem, it’s highly likely that they and opponents will go on simply talking past one another.

    Second, in characterising SRM as the only possible way of attenuating near-term
    climate damages, you need to explain why (presuming you believe that to be the case) CDR approaches cannot play a meaningful role.

    Third, and imo meriting much more attention than you give it, is the question of what sort of SRM schemes might be introduced in practice. Not only does it appear that these might be much more difficult to control and fine-tune than the ideal scenarios suggest; but we need to consider real politics. Who would control the system, and with what objectives? This is the crux of the problem: an ideal scenario for
    fair mitigation has existed for decades, but the world hasn’t adopted it. Models of fair adaptation have been widely understood for years, yet the political arguments continue. It seems to me that to rely on the possibility that there might now be a happy coincidence between the immediate interests of the poor world and the wealthy elites of the rich global North when it comes to SRM is a very dangerous path. The structural disadvantages of the global South will not be tackled by SRM, and may even be reinforced, even if the technology ameliorates suffering in the short term. The challenge progressive interests face is how best to address both of those problems, not just one of them.

    I agree that progressive interests should not seek to prevent more geoengineering
    research, but they would be wise to press for it to be ethically responsible; trans-disciplinary; socially and politically informed; and guided and reported in ways that limit the risk of moral hazard. And I think that means avoiding sweeping claims that ‘there is no alternative’, instead allowing space for real public deliberation over the possible mixes of accelerated mitigation (including both technological and behavioral changes), elevated adaptation, CDR, and potential SRM technologies, and the various ways in which they could be governed and managed.

    Thanks again for stimulating this important discussion.

  • Joshua Horton

    Thanks Duncan. Let me address the issues you raise point by point.

    On moral hazard, in the second paragraph I mention “other objections to geoengineering, many of which are valid and must be thoroughly weighed and considered,” and indeed I regard concerns about moral hazard/risk compensation to be just such valid objections that must be addressed. While it’s certainly plausible that SRM might result in reduced mitigation, it’s equally plausible that SRM might lead to
    more mitigation. Right now we simply don’t know, which is why the question must be researched. But not foregrounding this issue in a short blog post about a separate issue is not the same as failing to “acknowledge the problem.”

    On CDR, the simple and as far as I know uncontroversial answer is that neither existing nor imagined CDR methods could plausibly draw down enough carbon quickly enough to meaningfully reduce potential climate damages over the next couple of decades.

    On the specific design of potential SRM schemes, I fail to see why it is incumbent on me to specify such architectures in a blog post justifying more research on SRM because it might greatly benefit the world’s poor. Certainly this issue raises
    fascinating questions, but insisting that delivery schemes and governance mechanisms be spelled out in advance is akin to demanding that a health care system must be reformed and performing optimally before promising research on new cancer treatments is allowed to move forward.

    Overall I think it’s important not to lose sight of what you fairly describe as my “central conclusion,” with which you evidently agree—given their interests and concerns, the progressive left should be promoting geoengineering research rather than seeking to stymie it.

  • cyclonebuster

    These solve the issue in 5-10 years once placed into operation. Arctic ice extent and mass will return to 1979 levels…