I really think that most people sail around in a blithe balloon of denial, assuming that the impact of global warming will simply be a surge in demand for iced tea and freon. The Disgruntled Chemist has another really good post on potential environmental consequences:
[A] warmer atmosphere means a wetter atmosphere. When the air is warmer, it can hold more water before it has to get rid of it in the form of rain or snow. This does not mean that there will necessarily be less rain, just that when it does fall, it's gonna fall hard. Extreme weather events will come more often, and they'll be more extreme. Get used to storms, especially if you live in higher latitudes.Pick your poison: the ominous predictions of scientific experts who stand to reap no financial reward, or a bunch of Rolex-clad, BMW-driving lobbyists getting rich off protecting the rights of industry to pollute with impunity. Me I'm listening to the guys with the Bunsen burners.
When it snows in higher latitudes now, the snow adds to the existing snowpack. This mediates the effect of all that water falling, and the runoff is spread over months instead of days, providing a steady water flow through the spring and a mediated water flow during storms. But when the snowpack gets smaller due to warming, this mediation won't happen. That means flooding, and in areas with poor sewage infrastructure, it means shit getting washed into the water supply.
Flooding = less clean drinking water = more disease.
In countries where agriculture is a big part of their economy, less irrigation water will mean major economic problems, which will in turn result in a decreased investment in water infrastructure (pipes, etc.). Governments only try to improve their citizens' access to clean water when economic times are good (Gadgil, Annu. Rev. Energy Environ., 1998 - not online, sorry).
Another scary possible consequence of reduced streamflows is war. Seriously. In 1998, Turkey and Syria almost went to war over ethnic problems with the Kurds, exacerbated to a great extent by a dispute over the Euphrates. Turkey has been building huge dams on the river for power and irrigation, but this means fertilizer runoff and less water gets into Syria. Syria gets more than 80% of its water from the Euphrates. If the flow lessens and Turkey doesn't adjust its usage accordingly, things could get tense there again.
So why am I writing this? Well, it seems like there are a lot of misconceptions out there about the impacts of this "global warming" thing. People either believe the government that it's not going to happen, or they think that things are just going to get really hot, and we'll crank our air conditioners and be fine. Well, I'm here to tell you that it won't be that way....It is not going to be pretty if we keep going like we're going.
(photo courtesy stock.xchng)