Looking back one, two and five years ago today on Worldchanging:

2009
Ashley Murray: Wastewater is a Resource
Zoë Chafe nominates Ashley Murray as part of Worldchanging's Attention Philanthropy Campaign; find out more about Ashley's work to help local governments design and retrofit sanitation systems for water reuse...

2008
Cowpooling and Super-Spikes, New Words Help Define Our World
The words we use matter, and to keep apace with our quickly changing world, we are constantly looking for ways to describe how change is happening and how we feel about it. Here’s a sample of some (possibly) new sustainability-related words, for your repartee...

2005

On A Day Like Today
Jamais Cascio reflects on the tragedy of the London bombings, and writes that "on a day like today, it's especially hard to write about solutions, but on a day like today, it's all the more important to do so"...

Other recent "look backs":
July 2
July 5
July 6