As the Eyjafjallajokull volcano reminds us that Nature doesn't just mess with people in the third world, I'd like to direct people's attention to two very informative books dealing with climate change...and this would be real and documented climate change, not the Al Gore/James Hansen junk science silliness that everyone considers "climate change" these days. Presented for your edification: The Long Summer and Flood, Famines, and Emperors, both by Brian Fagan. Fagan is Emeritus Professor of Anthropology at UC-Santa Barbara who has written extensively on the effect that the vagaries of climate have had on past civilizations. The two books I've cited are both very readable and, I'd say, reasonably accessible to the non-technical reader.
In both books, Fagan references anthropogenic global warming and makes the expected worrisome comments about a future of human-induced climate change. However, his careful cataloging of ten thousand years of climate changes provides a powerful argument for a more measured interpretation of recent climate "changes". Two general observations stand out in reading Fagan's books. First, all significant climate change since the end of the last Ice Age has been driven by changes in ocean and air currents. Second, and more significant, is how frequently the phrase "we don't know why.." appears in Fagan's descriptions. Fagan admits that the mechanisms that drive changes in ocean and air currents are poorly understood and this is a significant revelation in a time when climate "scientists" are making dire and, apparently, precise predictions on the effects of the average global temperature changing by a few tenths of a degree.
What is known about ocean and air currents is that they are driven by convection; warm air (or water) rises and cool air (or water) sinks. Temperature differences between the poles and the equator provide an engine for the movement of air and water on an inconceivably massive scale. Throw in some continents, island chains, ocean basins, and deep ocean trenches and you have a lot of quasi-stable ocean currents set up that defy modelling...and this fact points to the very heart of the intellectual dishonesty of the climate change gloom and doomers. Even if we assume that human activity has caused the average global temperature to rise (and let me stress that this is an "if" that puts us close to the realm of science fiction), we don't know how that is going to change the climate and we know so little about movement of air and water on a global scale that it is impossible to say that a global temperature rise would be a bad thing.
What Fagan does point out is where the very real danger of climate change lies. An astounding 70 percent of the world's population live in regions that would be affected by a significant El Nino event such as those that ended the Mayan civilization in Central America or drove the Anazasi out of the New Mexico deserts. Both of these cultures were dependent upon very intensive farming on a limited amount of available land. When an El Nino event triggered a multi-year drought, both cultures collapsed.
Fagan points out that with the earth's present population of 6 billion people, essentially all agriculture is as intensive as that feeding the Maya and Anazasi cultures and that literally hundreds of millions of people are currently dependent upon the agricultural output of marginal lands that would become untenable in a major El Nino event. As Floods, Famines, and Emperors makes clear, the shifting of trade winds and ocean currents in the central Pacific that characterizes an El Nino is a global event that affects weather around the entire globe in ways that are not clearly understood - again, let me stress the "not clearly understood" aspect here. A significant El Nino could cause agriculture to crash in places as far away as sub-Saharan Africa, south Asia, and China with the resultant famine and subsequent unrest destabilizing governments and economies around the world.
...and here lies the true crime of the scientists and bureaucrats who have built reputations, careers, and institutional empires on anthropogenic global warming. By squandering billions and billions of research dollars in their attempts to "prove" human-caused climate change, studies of the real and historically documented threats that climate change presents to humanity have been left largely under-funded. Fagan's books would suggest that it is only a matter of time - as in years, not decades or centuries - before we come to regret our ignorance.