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Climate Change


April 29, 2018 | A version of this story appeared in Volume 96, Issue 18


Letters to the editor

Solar geoengineering

Playing with the atmosphere (March 26, page 28) is a really bad idea. You can call it what you want, but it’s a bad idea. No one in this century has the knowledge necessary to play with the atmosphere. There is no current modeling that would predict all the side effects of playing with the atmosphere. Many astronauts and two space shuttles have been lost. Now we are letting driverless cars loose on public roads, and how is that experiment going? At least SpaceX is not hurting anybody. We have tremendous knowledge, but not enough in this case.

Cover for C&EN, March 26, 2018
Credit: Will Ludwig/C&EN

We need to get our act together to stop polluting the atmosphere. Seems improbable that adding more chemical pollutants to the atmosphere is a good idea. Look what we did to the stratospheric ozone layer. Yes, go ahead and do lab experiments because it is best to be prepared, but we simply do not have the knowledge to do this on a planetary scale. There is probably no good return scenario from what would be done even if it works.

Why give industry this crutch? Industry still has not learned anything during the past 100 years and over my industrial career. Industry needs to take ownership of its activities and not produce Superfund sites. As we continue to turn the atmosphere into a Superfund site, we as consumers pay for everything already, monetarily and with our health. The major problem with industry is that new ideas are meddled with from the beginning to reduce costs. Hence unforeseen side reactions, possibly many years later, happen—some benign, but many severe.

There are unethical people in every profession, and science is no exception. The life on Earth factor is just too great for people of this century to play with Earth’s atmosphere. Fix industrial pollution, and global warming becomes more manageable for all species on Earth, but already global warming is showing global effects, and so quick action is required.

David Wynn
Menasha, Wis.

Thank you for the wonderful article on solar geoengineering. The issue in my opinion is simply that knowledge can be dangerous, but ignorance is worse. The logical extension of those who don’t want this studied is to ban all genetics, nanomaterials, and nuclear research—and maybe all science. Would we be better off if astronomy was permanently banned 500 years ago and we still thought we were the center of the universe?

Alan Burnham
Livermore, Calif.

The question “Will the world ever be ready for solar geoengineering?” is moot. We already are geoengineering, not just with carbon dioxide but with hundreds of other chemicals that we are dumping into the environment in metric-ton quantities. We still have not learned the obvious lesson that there are always unintended consequences. With CO2 the consequences are more dire: the prospect of the end of civilization within the next century or two.

I submit that the solutions to climate change are not primarily technical. There are myriad technologies for living sustainably, from primitive self-sufficiency to biospheres suitable for Mars. Plus there is not enough time for the development and deployment of totally new technology, which takes 30 to 50 years. We have a decade or two to bring our carbon footprints to near zero (CFZ), or we will pass the point of no return. I also do not see a political solution. The prospect of the U.S., let alone the world, deciding to abandon the current economic paradigm to save the world is near zero. The only viable solution I see is for each of us to think about how to implement current technology into economically viable systems to achieve CFZ, do it, and tell others. My own plan involves a Stirling engine, parabolic troughs, and thermal storage. “If you want to make the world a better place, take a look at yourself and make a change.” That is the most effective solar geoengineering.


Mark W. Schauer
Peterborough, N.H.

Might it be useful to bring back the supersonic transport? The threat of stratospheric pollution was one of the reasons the SST was abandoned in this country. That “pollution” could be turned into an advantage by burning cheaper, “dirty,” sulfur-rich fuel as a means of injecting sulfur dioxide into the stratosphere. The result: faster travel, cheaper fuel, and a mitigation of global warming.

Howard J. Wilk

The feature article and cover page in the March 26 edition on solar geoengineering caught my eye. An overriding question, at least in my mind, in the whole debate on climate change is the ideal temperature. If we had the control, knowledge, and wisdom to dial in water and ground level temperature, precipitation, and such for every sector of the planet, what would that be?

If we miscalculate and put a city under a glacier, who will make an apology, and who will repair the damage? If we bankrupt a farming community by shortening the growing season a bit too much, who will support those starving people? If someone freezes to death for lack of heating fuel, who will bring that person back to life?

I suggest that meddling with fundamental human conditions such as climate or genetics, without adequate understanding of these very complex systems, will lead to chaos. When we still can’t predict weather conditions 10 days from now, how do we expect to make good choices that will have generational impact?

If we think we can play God, we will be very unpleasantly surprised.

Michael Kerner
Lisle, Ill.

The article “Will the world ever be ready for solar geoengineering?” is a must read not only for chemists and engineers but for every concerned citizen of the globe.

Whether or not such extreme and risky measures will ever be needed and implemented by a desperate future generation is actually up to this generation. Are we willing to pay the (considerable) price for drastically reducing emissions to respond to climate change now, or are we going to keep kicking the can all the way to the end of the road, where there will be no more choice?

Anthony Foris
Wilmington, Del.

Geoengineering research, aimed at learning how to minimize risks should global warming have unacceptable consequences, has been suppressed by the environmentalist movements of the world, whose members are more familiar with the science of clean energy than with engineering and economic realities. C&EN has devoted far fewer articles telling the community of chemists and chemical engineers that the increase in atmospheric CO2 levels has historically scaled with, and continues to scale with, global wealth, i.e., the product of the population and the per-capita gross domestic product (GDP). The population of our planet increased 1.25-fold in the past 20 years, and the constant-dollar global per-capita GDP has doubled, increasing the global wealth by a factor of 2.5. Although the association between global wealth and atmospheric CO2 has been long known to economists, the press did not sufficiently cover it.

C&EN failed to tell its readers that the global efforts of energy conservation and on renewables of the past 20 years reduced the slope of the curve relating atmospheric CO2 to global wealth only by about 10%. Because people wish to have families of size and seek to live better, the likelihood of the CO2 levels reaching catastrophic levels remains high in spite of the global conservation and renewable energy efforts. The world is emerging from its historical poverty and will continue to do so. It is, therefore, timely to increase the research of all options that humanity has. The social acceptance of the necessary research depends substantially on journalists, including the writers of C&EN.

Adam Heller
Austin, Texas

This story is well written, but I was surprised that it leaves out an important aspect raised by Gabriele Hegerl and Susan Solomon some time ago (Science 2009, DOI: 10.1126/science.1178530) when this topic first reared its head, which is that solar radiation management, as proposed, is likely to coincide with reduction in precipitation, notably over developing countries. The Mount Pinatubo eruption did cool the hemisphere, as pointed out in the piece by Tien Nguyen, but also coincided, in lockstep with the Pinatubo emission event, with considerable reductions in continental discharge and land precipitation. To paraphrase Dana Dlott, who stated this to me first, “I’d like to try this out on a few hundred other planets first.”


April 16, page 16: A profile of chemist David Liu incorrectly stated that a postdoc, Nicole Gaudelli, created an adenine base editor with the help of an enzyme evolution tool called PACE. In fact, she used a bacterial selection system designed for the purpose of evolving the adenine base editor.

April 16, page 22: The feature story about raincoats incorrectly stated that polyurethane coatings in rainwear are on the fabric’s backer. They are, in fact, on the side of the PTFE membrane that touches the backer.

Franz Geiger
via C&EN’s website


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