https://www.theguardian.com/commentisfree/2021/apr/22/climate-crisis-emergency-earth-day
Some say we can ‘solar-engineer’ ourselves out of the climate crisis. Don’t buy it Ray Pierrehumbert and Michael Mann <https://www.theguardian.com/profile/michael-e-mann> What could go wrong with this idea? Well, quite a lot [image: A coal-fired power station near Liverpool, England.] ‘The heating effect of carbon dioxide persists for ten thousand years or more, absent unproven technologies for scrubbing carbon dioxide out of the atmosphere.’ Photograph: Phil Noble/ReutersAs we arrive at Earth Day, there is renewed hope in the battle to avert catastrophic climate change. Under newly elected president Joe Biden, the US has reasserted global leadership <https://www.theguardian.com/us-news/2021/mar/31/biden-infrastructure-plan-address-climate-crisis> in this defining challenge of our time, bringing world leaders together in Washington this week <https://www.whitehouse.gov/briefing-room/statements-releases/2021/03/26/president-biden-invites-40-world-leaders-to-leaders-summit-on-climate/> to galvanize the global effort to ramp down carbon emissions in the decade ahead. So there is promise. But there is also great peril looming in the foreground. Just as the world, at long last, is getting its act together, an ominous sun-dimming cloud has appeared on the horizon <https://michaelmann.net/content/my-comments-new-national-academy-report-geoengineering>, threatening to derail these nascent efforts. That cloud comes in the form of technologies whose proponents call – somewhat deceptively – “solar geoengineering”. So-called “solar geoengineering” doesn’t actually modify the sun itself. Instead, it reduces incoming sunlight by other means, such as putting chemicals in the atmosphere that reflect sunlight to space. It addresses a symptom of global heating, rather than the root cause, which is human-caused increase in the atmosphere’s burden of carbon dioxide. While it is certainly true that reducing sunlight can cause cooling (we know that from massive but episodic volcanic eruptions such as Pinatubo in 1991), it acts on a very different part of the climate system than carbon dioxide. And efforts to offset carbon dioxide-caused warming with sunlight reduction would yield <https://journals.sagepub.com/doi/full/10.2968/064002006> a very different climate, perhaps one unlike any seen before in Earth’s history, with massive shifts in atmospheric circulation and rainfall patterns and possible worsening of droughts. What could possibly go wrong <https://ncse.ngo/preview-madhouse-effect>? Elizabeth Kolbert’s book Under a White Sky <https://www.theguardian.com/books/2021/mar/26/under-a-white-sky-by-elizabeth-kolbert-review-the-path-to-catastrophe> documents case after case where supposedly benign environmental interventions have had unintended consequences requiring layer after layer of escalating further technological interventions to avert disaster. When the impacts are local, as in Australia’s struggle to deal with consequences of deliberate introduction of the cane toad, the spread of catastrophe can be contained (so far, at least). But what happens when the unintended consequences afflict the entire planet? Then there is the mismatch of time scales. The heating effect of carbon dioxide persists for 10,000 years or more, absent unproven technologies for scrubbing carbon dioxide out of the atmosphere. In contrast, the sun-dimming particles in question drop out in a year or less, meaning that if you come to rely on geoengineering for survival, you need to keep it up essentially forever. Think of it as climate methadone. And if we are ever forced to stop, we are hit with dangerous withdrawal symptoms – a catastrophic “termination shock” wherein a century of pent-up global heating emerges within a decade. Some proponents insist we can always stop if we don’t like the result. Well yes, we can stop. Just like if you’re being kept alive by a ventilator with no hope of a cure, you can turn it off – and suffer the consequences. Geoengineering evangelists <https://www.theguardian.com/environment/2021/feb/08/solar-geoengineering-test-flight-plan-under-fire-over-environmental-concerns-aoe> at Harvard have pushed for expanded consideration of such technology; as panic over the climate crisis has grown, so too has support for perilous geoengineering schemes spread well beyond Cambridge, Massachusetts. And the lines between basic theoretical research (which is worthwhile – climate model experiments, for example, have revealed <https://physicsworld.com/a/solar-geoengineering-could-cause-unwanted-changes-in-climate-new-modelling-suggests/> the potential perils) on the one hand, and field testing and implementation <https://link.springer.com/article/10.1007/s10584-020-02740-3> on the other, have increasingly been blurred. Solar geoengineering has been cited <https://www.rollingstone.com/politics/politics-news/geoengineering-house-democrats-climate-plan-2020-1023376/> in the Democratic Climate Action Plan. MIT’s Maria Zuber, incoming co-chair of Biden’s president’s council of advisers on science and technology (PCAST) is on record as favoring <https://issues.org/solar-radiation-mitigation-research/> an expanded federal geoengineering research program. And now the other shoe has dropped – the US National Research Council has recently released a report going well beyond <https://michaelmann.net/content/my-comments-new-national-academy-report-geoengineering> the very cautious, tentative recommendations for continued research in the 2015 NRC report <https://www.nap.edu/catalog/18988/climate-intervention-reflecting-sunlight-to-cool-earth> one of us (Pierrehumbert) co-authored. The new report <https://www.nap.edu/catalog/25762/reflecting-sunlight-recommendations-for-solar-geoengineering-research-and-research-governance> pushes for a massive $200m five-year funding program. The growing support is based on a fundamental misconception, captured in the NRC report’s justification statement: that we likely won’t achieve the necessary decarbonization of our economy in time to avoid massive climate damages, so this technology might be needed. Such “Plan B” framing is the worst possible justification for developing solar geoengineering technology. It is laden in moral hazard – providing, as it does, an excuse for fossil fuel interests and their advocates to continue with business as usual. Why reduce carbon pollution if there is a cheap workaround? In The New Climate War, <https://scribepublications.com.au/books-authors/books/the-new-climate-war> one of us (Mann) argues that geoengineering advocacy is indeed one of the key delay tactics used by polluters. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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