
Looking back one, two and five years ago today on Worldchanging:
2009
Canada's Largest Green Roof
You know an innovation has hit its stride when it becomes scalable...and green roof design has risen to the occasion. Case in point: the new Vancouver Convention Center.
2008
Peak Guano
Through "catalytic innovation" humanity has lived through peak phosphorous before.
2005
5P
Four "pro-poor public-private partnerships" (5P) projects in Sri Lanka, Indonesia, Thailand and Pakistan are explored, each emphasizing a different key Millennium Development Goal category: water, electricity, health care and biodiversity.
Other recent "look backs":
April 7
Thoughts on this series: while it's always interesting to review where you've been, it would be even more interesting to see where some of these things have gone since.
Now, you folks have your hands full as it is, so I suggest that readers do a bit of following up themselves and report on it in the comments as and when it seems appropriate.
