Looking back two and five years ago today (give or take!) on Worldchanging:

2008
Understanding our Impact on the Planet
Alex Steffen reflects on Michael Tobis's essay "My Little World (And Yours, Too)" and the ideas of ecological footprints and one planet living...

2005
Megacities and the Environment
Alex Steffen shares a link to an article that offers a "damn fine overview of the problems" megacities face, as well as some links back to bright green solutions...

Other recent "look backs":
September 14
September 15
September 16