Northern Hemisphere Pollution a Cause of '80s Africa Drought 158
vinces99 writes "Decades of drought in central Africa reached their worst point in the 1980s, causing Lake Chad, a shallow lake used to water crops in neighboring countries, to almost dry out completely. The shrinking lake and prolonged drought were initially blamed on overgrazing and bad agricultural practices. More recently, Lake Chad became an example of global warming. But new University of Washington research shows the drought was caused at least in part by Northern Hemisphere air pollution. Particles from coal-burning factories in the United States and Europe during the 1960s, '70s and '80s cooled the entire Northern Hemisphere, shifting tropical rain bands south. That meant that rains no longer reached the Sahel region, a band that spans the African continent just below the Sahara desert."
The real question.. (Score:5, Interesting)
If that was caused my industrial pollution in the U.S. 30-odd years ago, what can we expect from the pollution China is dishing out?
I don't think this is the whole story (Score:5, Interesting)
This [wisc.edu] goes much further into explaining some of the variance, both seasonal and longish-term (only goes back to the Fifties), of water table levels in the entire Chad basin - a system that covers a tenth of the entire African continent, not just a relatively small body of surface water. The human impact, according to that paper, accounts for about one twentieth of the total variance in the system but as much as 40% of the surface area of the lake itself (and up to half the volume), with most of that variance originating upstream in tributary river systems. AGW is barely even considered (or even mentioned, going by a quick scan down the paper), since the effects of AGW, if it even exists, have not been or cannot currently be measured because until it is properly defined, nobody even knows what to look for. It does deal with precipitation, which has had a bit of a lull over recent decades (1985-1994 being particularly dry years), but again this deals with the entire system not just the lake.
It's about consequences ... (Score:4, Interesting)
Personally, I don't buy into the global warming camp or anti-climate change camp. I recognize that the system in question is far too complex for us to understand with certainty. I also recognize that the system is "easy" to understand within statistical certainties, which are not reported often enough. I am also sane enough to recognize that my education in astrophysics only gives me some understanding into the issues of anthropomorphic climate change, rather than a complete understanding of it. I also recognize that my education gives me less understanding in it than climatologists, yet more understanding in it than scientists who never deal with problems at a planetary scale.
Yet one thing I am certain of: actions imply consequences. The consequences may be positive, negative, or neutral. Whatever the outcome, we must make an attempt to understand it. Our best means of understanding it are scientific. Political attempts to understand it only tell us if the consequences are desirable, thus they must come after scientific attempt to understand it. Other means of understanding climate change are likely based upon invalid systems of knowledge, and ought to be rejected altogether.
To make a long story short: I'd have to read the paper itself to judge the degree to which it's valid. Given that it is based upon scientific principles, I'm going to have to plead: I'm human, I have limited resources to deal with the problem presented before me, it is based upon a system of knowledge that I find acceptable (i.e. science), so I accept it.
As long as the authors are being intellectually honest, I believe that it is a valid way to accept their conclusions. (If they aren't intellectually honest, I'll hate them but still stand by the principle: actions imply consequences, now figure out what the consequences are.)
Re:It's about consequences ... (Score:3, Interesting)
It's driven by the creationist idiots that think God created a perfect unchanging world so any suggestion of change is a spit in God's eye.
I know it's wrong to try to respond to flamebait, but you have it backwards. It's the people who think that the way the world is right this very minute is the way it is always supposed to be and we must do everything we can to keep it static that are the problem, and they aren't the religious nuts, they're the eco-nuts. They admit that they know about ice ages and the lush, tropical periods that the dinosaurs flourished in, but somehow today is perfect and no change, man-made OR natural, can be allowed to happen. Yes, it was different before, but it can no longer be different because we like it the way it is.
They're the ones bemoaning the extinction of species that no longer fit the climate or environment, and trying to build seawalls to stop the ocean from eroding that spit that developed a mere fifty years ago, but they've built their home on it and it must be preserved because it's "natural" and that's how it has "always been". The very people who hurl insults at "those religious nuts" for not accepting Evolution as the origin of life are the ones who try to stop true evolution and survival of the fittest from happening.
It's a pity they think their God is so limited.
Backwards again. Religious people know God isn't limited. It's the atheists who cannot fathom a God with powers they cannot personally understand or account for.
You don't see the religious right out protesting for carbon cap and trade or against energy users or producers. They know better. Change happens. It is Hope and Change doesn't.
Re:Who's to blame? (Score:3, Interesting)
Re:Oh no... (Score:5, Interesting)
Having said all that, climate scientists don't really talk about cooling or warming, they talk about +ve and -ve forcing and feedback [wikipedia.org], two forcings with different signs can indeed cancel each other out. To confuse matters further CO2 can be both a forcing (humans, volcanoes) and a feedback (melting permafrost, increased bushfires). Feedbacks have far more uncertainty associated with them than forcings. When everything is taken into account you can work out a figure called "climate sensitivity" (CS). The CS in models compares very well with the CS derived from geology and really hasn't changed that much since the 70's.
All this is just a sample of the complexity that adds up to ripe pickings for people who have no problem deliberately misinforming the public for personal gain [sourcewatch.org].