Meltdowns, Droughts, and Floods

9 08 2006

They’re having a tourist problem at Igazu Falls, down on the border between Brazil and Parguay. The falls is usually bigger than Niagra, but this summer it is flowing at about a fifth of its usual rate. Can you imagine the Cumberland River flowing at a fifth its usual rate? It’s not just bad news for the tourists—it means the whole southern part of Amazonian Brazil is drying out, along with much of the Amazon basin proper. Equatorial South America is in its second year of drought; biologists have discovered that two dry years is about all the shallow-rooted rain forest can take before it dies, leaving savannah in its place. If the Autumn rains don’t come, that’s what’s likely to happen.

Apparently, two factors are combining to dry the climate. One is the global warming trend, which is diminishing snowpack in the Andes, a major source of the Amazon’s year-round water supply. With less snow and more rain falling on the Andes, the seasonal highs and lows of the rivers are getting both higher and lower. The other factor is rain forest removal, which the Brazilian government, even with the best of declared intentions, does not have the political will or military strength to stop. Apparently, enough of the rainforest has been removed to cut into the forest’s self-generated rain cycle. When there were enough trees, the moisture they gave off in the course of a day would coalesce into rainclouds and fall back down on the forest; with fewer trees, the moisture just evaporates and blows away.

The Amazon rain cycle has strong, complex effects on the whole hemisphere’s weather. A dry Amazon will change our climate in ways that are hard to predict, except to say that we probably won’t like them. No wonder the Venezuelans are planning to plant millions of trees with some of their oil money. They’re going to need all the buffering they can get.

Now—from the equator to the poles—in Greenland, the pace of meltdown is picking up, as is the pace of earthquakes. With less ice weighing on it, the ground is rebounding, pushing the ice into the sea even faster. Last year, 2005, Greenland lost about 50 cubic miles of ice—this year, it looks like it’s losing about a hundred cubic miles of ice. In Antarctica, there are 5200 square miles less sea ice than there were just ten years ago, and the volume of icebergs that break off the West Antarctic shelf has doubled in the last ten years. It is expected to double again in the next ten years.

The sea ice once served to dam up subglacial rivers in Antarctica; now that it is diminished, many of these subglacial rivers are flowing into the sea, eroding the Antarctic’s mainland ice and raising sea level further.

sourcelink

Ice melts in a mathematical, rather than an arithmetical progression. That is, the melt rate is not 1, 2, 3, 4, 5, 6, 7—it’s 1-2-4-8-16-32-64. It snowballs, you could say. With both Greenland and the West Antarctic getting fragile, we have set ourselves up for a 40-foot sea level rise, with most of it potentially happening in just a year or two; and in a world that much warmer and more water-covered, the East Antarctic ice shelf is likely to start deteriorating, and that will raise sea level about another hundred and sixty feet. The good news is, there’ll be plenty of water in the Amazon basin again; the bad news is, it’ll be sea water.

A forty-to two-hundred foot rise in sea level is a real threat to our national security. Mr. Cheney has declared that “the American way of life is not negotiable”; we can see clearly now that his greed will result in the deaths of millions, possibly billions of people, and an end to “the American way of life” that the Bush junta is allegedly so intent on defending. America’s greed steals not just food but freedom from billions of people. Terrorists are just a symptom of this global disorder. As long as Mr. Cheney’s insatiable greed stalks the world, there will be terrorists, and there will be no intelligence agency in the world invasive enough to prevent desperate, angry people from expressing their frustration any way they can.

music:  Jackson Browne, “Before the Deluge”

p.s.

i’d like to find a map of what a 200-foot sealevel rise would look like, but
a couple of places to find maps of what a 40-foot sealevel rise would do can be found at

http://www.geo.arizona.edu/dgesl/research/other/climate_change_and_sea_level/sea_level_rise/sea_level_rise.htm

http://flood.firetree.net/


Advertisements

Actions

Information

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s




%d bloggers like this: