Climate science, as I understand it, predicts that climate change will bring more rainfall because of increased evaporation and because higher temperatures permit the air to hold more water vapour. Places that already have rainfall will have more rainfall. Places already prone to flooding will have larger floods. Major flood events will come closer together.
Colombia. “Over the past 10 months we have registered five or six times more rainfall than usual.” said Richard Lozano, director of Colombia’s weather service. Exceptionally heavy spring rains have left 3 million disaster victims, caused billions of dollars in damage, and killed at least 425 people, with another 482 others missing.
Mississippi. The Army Corps of Engineers have now opened all of the river system’s major spillways—the escape valves of the Mississippi flood-control system—for the first time in history. The opening of the Morganza Floodway will affect thousands of people and large areas of land in Louisiana’s Cajun territory but was deemed necessary to protect weaker areas of the levee system downstream. A breaching of those parts of the system would have resulted in disaster in New Orleans worse than Katrina.
Manitoba. Flooding on the Assiniboine River is being called a “300 year flood.” An area of 180 square kilometres (70 square miles) west of Portage la Prairie was deliberately flooded on Saturday to protect against a more dangerous breach downriver.
Update: North Dakota. The same set of flood conditions which brought record-shattering floods to Manitoba and the Mississippi basin in May, were set to bring record-breaking floods to North Dakota. Minot was expected to be the centre of them, and fleeing homeowners moved their belongings to the second floor in expectation of the rising waters. Then came a huge downpour, 4 to 6 inches of rain over a large area of already water-saturated territory, and the flood is now expected to be up to nine feet higher than expected. The homeowners goods are going to be lost to the flood anyway, and other homeowners at the edge of the former evacuation zone are now being told to watch out for their belongings at ground level. There is simply no historical precedent for the kind of flood now expected in Minot this weekend.
(Update 30 June 2011) China. Torrential rains in China from June 13 to 19 have caused 500,000 people to evacuate their homes, while affecting the lives of millions more.
(Update) Alberta – Slave Lake, earlier this year devastated by a wildfire which burned down 40% of the town, is now being hit by flooding. One resident says of the flooding, “This is the worst we’ve ever seen and the neighbours have seen as long as they’ve lived here, and they’ve been here for generations.”
The increased evaporation also means that those places which are already dry become even drier. Droughts in drought prone areas will increase, and these areas will become larger in geographic extent.
Higher temperatures are also directly linked with an increase both in number and seriousness of wildfires, and with a lengthening of the wildfire season because of the progressively earlier arrival of spring.
Texas, Arizona, North Carolina, New Mexico. Because of extended drought conditions Texas has been fighting huge wildfires since April. Similar conditions are driving wildfires in Arizona, New Mexico and North Carolina.
East Africa. Droughts used to come to East Africa every nine or ten years. Then it was every five years. Now it is every two or three years. The increasing frequency is making it more and more difficult to recover from the droughts and millions of people are being affected.
Eastern North America. Then of course there’s Hurricane Irene, brought to us by North Atlantic waters 2 degrees warmer than usual….