Tim Holland, a graduate student in Geography at McGill, working with Andy Gonzalez and Greg Mikkelson, and I has recently mapped out US household inequality (using the Gini coefficent to measure inequality) at a county level for 1970, 1980, and 1990. The inequality data is from François Nielsen at University of North Carolina – Chapel Hill.

The striking increase in USA inequality between 1970 and 1990 primarily occured in the 1980s. The spatial pattern of inequality is interesting, but perhaps unsurprising. Why inequality decreased in some counties in the central USA is perhaps more interesting.

For comparison, below is a map of international inequality from Wikipedia (note the color scheme is slightly different).

Gavin Schmidt has an interesting post on Art and Climate Change on the Real Climate weblog.

As anecdotal evidence of past climate change goes, some of the most pleasant to contemplate involve paintings of supposedly typical events that involve the weather. Given the flourishing of secular themes in European art from the Renaissance on, most of this art comes from the 16th to 19th centuries. As readers here will know, this coincides (in the public mind at least) with the so-called ‘Little Ice Age’ and somewhat inevitably this canon of work has been combed over with a fine tooth comb for evidence of particularly cold conditions.

The image that brought this issue to mind was seeing ‘Washington crossing the Delaware’ at the Met the other day and seeing the iceberg-like ice it was imagined (75 years after the event) that the rebels had had to row through in 1776. The first thing I noticed was that the ice is completely wrong for a river (which is just one of the errors associated with this picture apparently). River ice is almost always of the ‘pancake’ variety (as this photo from the Hudson river shows), and doesn’t form ‘growlers’. However, the confusion of artistic license with climatology appears to be a bit of a theme in other oft-cited works as well….

From World Resources Institute‘s Watersheds of the World (2003) visualizations of some social-ecological properties of the world’s major watershed:

Cropland Area by Basin

Average Population/km2 (1995)

Water availability per person (1995)

The map shows the 114 major watersheds in the world. The map includes the largest transboundary watersheds and small basins that are representative of a particular geographic area. Omitted regions, shown in white, are primarily smaller coastal drainage basins or regions with no permanent rivers (more info).