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A Sunshade In Space To Combat Global Warming
ultracool writes, "While the only permanent solution for human-driven global warming is developing renewable energy, a temporary hack to counteract possible abrupt climate change is to build a giant sunshade in space. The sunshade would be launched in small pieces by electromagnetic launchers, conventional chemical rockets being far too expensive. The sunshade could be developed and deployed in 25 years, would last about 50 years, and would reduce the amount of sunlight reaching Earth by 2% — enough to balance heating due to a doubling of carbon dioxide in the atmosphere." From the article: "The [trillions of] spacecraft would form a long, cylindrical cloud with a diameter about half that of Earth, and about 10 times longer... Sunlight passing through the 60,000-mile length of the cloud, pointing lengthwise between the Earth and the sun [at L-1], would be diverted away from our planet... The sunshade could be deployed by a total 20 electromagnetic launchers [collectively] launching a stack of [a million] fliers every 5 minutes for 10 years."
I wonder what else this would stuff up? Less light for photosynthesis for example.
Um...
/., actually) that they did a study and the amount of sunlight that actually reaches the surface of the earth has decreased by a whopping 10% since 1950. That alone puts a pretty huge dent in your theory. This is probably due to the fact that...
1. I'm pretty sure that I read (on
2. Life forms are surprisingly adaptive. You act as if plants are completely helpless in the face of a minor 2% change. I'm not saying there wouldn't be some long-term consequences (more to do with specific species thriving/suffering as opposed to planet-wide climate change) , but a permanent, perfectly linear/proportional drop in oxygen output is unrealistic.
3. Sunlight is only the energy source--plenty of other factors are involved in oxygen production.
4. I'm not at all sure that the greenhouse effect depends on gas proportions. You imply that the overall level of greenhouse gases could stay the same but if the relative amounts of other gases dropped, we would warm up. That's entirely possible, but that's not how I assumed it worked. Mars is pretty cold, and its thin atmosphere is composed (IIRC) mostly of CO2, so that seems to be another dent in your theory. Venus, on the other hand, has an extremely thick atmosphere of C02 and it's hotter than Mercury. From this, I would hazard a guess that raw quantities of greenhouse gasses are more important than percentages.
5. Even if greenhouse gases did have a proportional effect, the missing oxygen might very well be replaced by other inert gases. Plants aren't simple oxygen machines; they give and take in ways that I simply cannot recall (nor be bothered to Google) at 5:30 AM.
Oh, and personal responsibility doesn't work. Sorry. Wish it did... but it doesn't, so let's not completely neglect the worst-case-scenario plans, eh?
L1 one of the Lagrange points, i.e. points in space where the gravity of the sun and the earth cancel each other out. Objects stationed at these points do not fall towards either the earth or the sun.
Hi, welcome to slashdot.
I love this logic:
1. The climate has always been variable.
2. Therefore, man is not having an impact on today's climate!
QED, right?
Here's an exercise: Explain to me how increased levels of CO2 (which are rising due to humans- I challenge you to find an explanation that has not been debunked from here to Shanghai and back), which Arrhenius demonstrated over 100 years ago could cause climate change, can't possibly be causing climate change?
Hey, climate science is uncertain, and questioning it's results are fine. But if you are going to do so, please find a coherent argument why the current thinking is incorrect (again, please stick to the stuff that hasn't been shown to be wrong 100x over). So please go read RealClimate, debunk them, and then we can talk. Debating from ignorance is... ignorant.
PS I think this proposed solution, like most geo-engineering quick fixes, is f-ing nuts. For starters, it doesn't exactly have an 'Undo' button.
PPS Let's forget about climate change. How does changing the pH of the ocean by half a point grab you? We're doing that, too (the excess CO2 is going into the oceans), and we don't really know what the impact will be, b/c it'll reflect conditions the oceans haven't seen in a loooong time (and I'm not talking 1000 years. If memory serves, it's been several hundred thousand to millions of years. We do know that calcifying species will likely not be so happy, which some might argue is a problem. But hey, we couldn't possibly harm the planet, could we?
Simple Unexpected Concrete Credible Emotional Stories
"...It's like making a complex solution to a simple problem ..."
The weather system of the planet is about as far from "simple" as you can get. We have no clue about how the ecosystem of our world actually works. All this rancor about the "problem" of global warming and possible "solutions" are built upon an alter of such vast ignorance that I often find the discussion and "debate" of the topic to be the epitome of absurdity. The one prevailing predicate of almost every discourse about global warning and/or global climate change, is an unspoken implication that we (the human race) understand how the environment we live in works. WE DO NOT. And there exists a vast amount of historical evidence demonstrating that very notion.So the proposal of building a "shade" system for the planet to "cool it down" is so laughable due to the vast amount of hubris required to give it any consideration at all.
Perhaps we should work first on understanding the problem before coming up with solutions. Yeah, that means that the "I said it first" mentality will be hamstrung, but that, in my opinion, would be a good thing.
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