Rising sea levels are eating away at coastal sites, increased rainfall is eroding mud-brick ruins, creeping desert sands are blasting the traces of ancient civilizations, and the melting of ice is causing millennia-old organic remains to rot. "With climate change, we're feeling a sense of urgency," says University of Northern Colorado anthropologist Michael Kimball, who organized a panel discussion on climate change and archaeology at the World Archaeology Congress in Dublin last year. "It definitely focuses the mind."
For countless communities, archaeology can be a source of local identity, pride, and even income. "It may be intangible, but when a community loses its connection to history it loses something pretty important," says Kimball.
The International Panel on Climate Change (IPCC), a group of more than 1,000 experts on climate science convened by the United Nations, estimates that the world's temperature has risen about two degrees in the past century, thanks in part to an increase in carbon dioxide that traps heat in the earth's atmosphere. The consequences have already been dramatic. The world's oceans have risen four inches in that time. Weather patterns have also gotten less predictable and more extreme.
Over the next hundred years, the IPCC predicts that sea levels will rise at least another four inches. The worst-case scenario is truly frightening: a 10-degree rise in global temperatures, causing ice caps to melt and sea levels around the world to rise more than three feet.
Archaeologists can't stop global warming, but they can make dealing with it a priority. That may mean documenting sites before they disappear; in some places, simple steps like putting roofs over melting or rain-threatened areas are ways to preserve them. Action, however, must be taken soon. "Our job is not so much to talk about how to get climate change to stop," says Giovanni Boccardi, the chief of UNESCO's Asia and Pacific Unit. "While climate change is global, lots of solutions are local--and within our reach." What follows is a look at some of the threats facing archaeological sites around the world.