Essay by Eric Worrall
According to MIT researchers, blowing bubbles in space to block sunlight might be the solution to our climate woes. But MIT, like all the others, are ignoring a fundamental flaw with solar geoengineering schemes. Plants need sunlight.
MIT Scientists Propose Space Bubbles to Reverse the Worst of Climate Change
Published 2 days ago: June 17, 2022 at 4:48 am
A team of researchers at the Massachusetts Institute of Technology believe that we can mitigate the worst of climate change with… space bubbles. They’ve outlined a strategy in which a huge raft of bubbles, carefully positioned between Earth and the Sun, would deflect sunlight (and thus heat) to stop further global warming.
“Geoengineering might be our final and only option. Yet, most geoengineering proposals are earth-bound, which poses tremendous risks to our living ecosystem,” a web page dedicated to the solution reads. “If we deflect 1.8% of incident solar radiation before it hits our planet, we could fully reverse today’s global warming.”
The bubble array would be made of inflatable shields of thin silicon or another suitable material, according to the team. The bubble cluster would be placed in outer space at a Lagrange Point, where the Sun’s and Earth’s gravitational pulls create a stable orbit. The researchers also said that if the plan becomes a reality in the future, the completed array would be roughly the size of Brazil.
They admitted that one of the main concerns with their proposal would be the logistics of fabricating a large film, transporting it into space, and then unfolding it to form the bubble raft. They suggested fabricating the spheres in outer space to minimise shipping costs.
The main project website is available here.
This project seems more fun than other geoengineering favourites, like blowing sulphuric acid or lime dust into the stratosphere. But aside from immense cost, all these geoengineering fantasies suffer a fatal flaw.
If ever implemented, solar geoengineering could all cause a global famine.
Estimating global agricultural effects of geoengineering using volcanic eruptions
Solar radiation management is increasingly considered to be an option for managing global temperatures1,2, yet the economic effects of ameliorating climatic changes by scattering sunlight back to space remain largely unknown3. Although solar radiation management may increase crop yields by reducing heat stress4, the effects of concomitant changes in available sunlight have never been empirically estimated. Here we use the volcanic eruptions that inspired modern solar radiation management proposals as natural experiments to provide the first estimates, to our knowledge, of how the stratospheric sulfate aerosols created by the eruptions of El Chichón and Mount Pinatubo altered the quantity and quality of global sunlight, and how these changes in sunlight affected global crop yields. We find that the sunlight-mediated effect of stratospheric sulfate aerosols on yields is negative for both C4 (maize) and C3 (soy, rice and wheat) crops. Applying our yield model to a solar radiation management scenario based on stratospheric sulfate aerosols, we find that projected mid-twenty-first century damages due to scattering sunlight caused by solar radiation management are roughly equal in magnitude to benefits from cooling. This suggests that solar radiation management—if deployed using stratospheric sulfate aerosols similar to those emitted by the volcanic eruptions it seeks to mimic—would, on net, attenuate little of the global agricultural damage from climate change. Our approach could be extended to study the effects of solar radiation management on other global systems, such as human health or ecosystem function.
The reality is there is no level of global warming which would make it worth taking the risk of attempting to reflect sunlight to cool the Earth.
Even if the conditions of the Early Eocene (5-8C warmer than today) returned, tropical conditions most of the way to the Arctic and Antarctic, plants would still grow, and farms would still be productive. Almost certainly more productive than today.
Our primitive primate ancestors dominated and prospered during the extreme warmth of the Early Eocene, with populations of primates exploding across Africa, Europe and Asia. So we have strong paleo evidence that warm weather is no threat to primates. We also know from today’s world, the Earth’s tropics are some of the most productive regions in the world.
Solar geoengineering by contrast has the potential to mess up the entire ecosystem, and cause widespread starvation and crop failures. Not just because cool periods are less productive, but also because plants suffer immensely if they are deprived of sunlight – so much so, even a mild volcanic perturbation is enough to produce a noticeable dip in production.
Attempting to tamper with the amount of sunlight Earth receives in my opinion would be far more dangerous than any remotely plausible negative consequences of global warming itself.
Obviously this is a worst case scenario. The odds are negligible of a solar geoengineering project like this ever advancing sufficiently to be a threat to the global ecosystem. But given the evidence of negative consequences, in my opinion MIT scientists shouldn’t even be making the attempt to promote this lunacy.
via Watts Up With That?
June 18, 2022 at 08:12PM