Volcanic Winter

If you like meteorology- and have a little background in it- you will like Jeff Master's Weather Wunderblog. We are coming up on hurricane season, and I enjoy reading in-depth analyses of these storms. The Weather Channel used to do a fairly decent job of this, but they seem too caught up in breathless and shameless disaster programming these days to actually do decent weather analysis.

The reason I bring this up is that today's post is a fascinating examination of the climatic effects of large volcanic eruptions. Combining historical perspectives, the most recent results of climate modeling, and examples from both human experiences with, and geological history of, major eruptions, some of the passages are (to me at least) quite riveting. For example:

If a mega-colossal eruption were to occur today, it would probably not be able to push Earth into an ice age, according to a modeling study done by Jones et al. (2005). They found that an eruption like Toba would cool the Earth by about 17°F (9.4°C) after the first year (Figure 3), and the temperature would gradually recover to 3°F (1.8°C) below normal ten years after the eruption. They found that the eruption would reduce rainfall by 50% globally for the first two years, and up to 90%over the Amazon, Southeast Asia, and central Africa. This would obviously be very bad for human civilization, with the cold and lack of sunshine causing widespread crop failures and starvation of millions of people. Furthermore, the eruption would lead to a partial loss of Earth's protective ozone layer, allowing highly damaging levels of ultraviolet light to penetrate to the surface.

So if, like me, you are a fan of both the atmosphere and the geosphere, this would be a good time to check out this excellent blog.