“A Sunshade for Planet Earth,” an article* by Robert Kunzig that discusses serious scientific proposals to avoid global warming without the need to cut back on human CO2 emissions, was published in the November 2008 issue of Scientific American.
But I have not been able to find any discussion of this in the “mainstream” news media.**
I think it is fair to say that the “mainstream” news media is obsessed with the “global warming” issue. And, indeed, if the worst fears of global warming become reality, it is going to be a very serious problem.
The possibility that there may be a simple, cheap technological fix should therefore be great news.
Why didn’t the “mainstream” media discuss this?
Let’s be blunt – over the next few decades, human beings are going to continue to dump huge amounts of CO2 into the atmosphere. It is politically impossible for Europe, Japan, and the US to cut back dramatically on CO2 emissions in a way that will seriously impact our standard of living.
And, China, India, and other developing countries will dramatically increase their CO2 emissions in the next several decades.
Human CO2 emissions will in fact be higher, probably a great deal higher, in 2030 than they are today.
Now, it is possible that those increased CO2 emissions might not end up being a problem.
There are in fact compelling scientific reasons to conclude that human CO2 emissions cause the globe to be warmer than it otherwise would be.
But the devil is in the details. Without human CO2 emissions,would the earth naturally be in a warming or a cooling period? Is it possible that, without our CO2 emissions, the globe would actually be cooling, and that therefore we need those emissions to stabilize the global temperature?
Yes, it’s possible. Our current geological epoch is one of intermittent Ice Ages: for example, the so-called “Little Ice Age” started in the late Middle Ages and only ended in the 1800s. Perhaps, we would soon enter another "Little Ice Age," except for the protection provided by human CO2 emissions.
The other key question is: if anthropogenic CO2 is indeed causing warming, exactly how much warming will end up occurring?
That is much harder to determine than the “mainstream” media have admitted.
I have been interested in global climate modeling since the late ‘60s, long before “global warming” became a big political issue, and, as a physicist, I have some concept of the scientific and computational difficulties involved in modeling the global climate.
The scientific reasoning that indicates that human CO2 emissions will make the earth warmer than it otherwise would be is quite straightforward. But to calculate the actual value of that warming is fiendishly difficult.
It’s the clouds.
A major part of the problem is clouds: as the globe starts to warm, more moisture should go into the air. Water vapor is itself a “greenhouse gas,” and thus will tend to increase global warming. However, more water vapor also tends to mean more clouds, and clouds tend to reflect sunlight back into space and therefore reduce the effect of global warming.
And understanding clouds is very hard.
Among other things, cloud formation depends on the amount of dust and kind of dust in the atmosphere, and understanding how much and what kind of dust will be kicked up into the atmosphere under global warming is also very hard.
The amount of global warming also depends on how vegetation (and bacteria) respond to the CO2 increase and to the increase in temperature.
Bacteria are complicated.
The moral here is that when the “mainstream” media report that the “scientific consensus” expects a global warming of between x and y degrees, do not believe them.
This is not a problem that can yet be definitively settled scientifically: I am not confident that it can ever be settled.
It is hard.
So, I do not know if global warming will be a real problem or not. My “gut feeling,” for what it is worth, is that we may be on the verge of another natural cooling period, and that there may therefore not be much of a problem. But that may simply be “wishful thinking” due to my naturally optimistic disposition.
“Global warming” may indeed turn out to be a very serious problem.
So, what solution does the Scientific American article suggest?
The most promising solution seems to be to dump sulfur dioxide (about one-and-a-half million tons, in terms of the weight of the sulfur, per year) into the stratosphere. The estimated cost is between twenty-five and fifty billion dollars a year, a trivial amount when spread out over all the citizens of the industrialized nations. (Incidentally, we are already dumping much more sulfur dioxide into the lower atmosphere each year: this would be a very modest increase in our sulfur dioxide emissions into the atmosphere.)
This works by causing increased cloud formation in the stratosphere, which reflects sunlight and cools the planet. As the article notes, we have reason to be confident that this will work: the 1991 eruption of Mount Pinatubo in the Philippines dumped a lot of sulfur dioxide into the stratosphere and did indeed have a cooling effect.
Is it a perfect solution?
No – as I said above, climate modeling is hard.
There are questions about whether this will have an effect on ozone holes over the arctic and antarctic, how it will affect different regional climates, etc.
And, the article also discusses other possible methods of counteracting global warming, although I myself found the sulfur dioxide approach to be the most promising. (The sea salt scheme bears further looking into, but the idea of a literal sunshade in space, while theoretically possible, is, in my judgment, not practicable.)
Go to your library and read the article yourself.
And then ask yourself: why did you not hear about this in the “mainstream” media?
The “mainstream” media are, after all, obsessed with global warming: they should find this welcome news.
Exactly what game are the “mainstream” media playing?
* The article is behind a wall; only the introduction, Geoengineering: How to Cool Earth-- At a Price is available for free online. Fortunately, any decent library has Scientific American.
**A Google search on the title, restricted to the last year (i.e., all the time since it was published) brings up less than three hundred hits (many to other pages on the Scientific American site that link to the article) – none in “mainstream” US news media, except of course for Scientific American itself.