Earth Becomes Brighter; No One Sure Why

Kenneth Chang in the New York Times:

Reversing a decades-long trend toward “global dimming,” Earth’s surface has become brighter since 1990, scientists are reporting today.

The brightening means that more sunlight – and thus more heat – is reaching the ground. That could partly explain the record-high global temperatures reported in the late 1990’s, and it could accelerate the planet’s warming trend…

Some scientists have reported that from 1960 to 1990, the amount of sunshine reaching the ground decreased at a rate of 2 percent to 3 percent per decade.

More here.