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

2009
See it Before it Disappears: Reconciling and Regulating Disaster Tourism
Carissa Bluestone examines the growing interest in 'see it before it's gone' tourism, its impacts on local economies, and how to participate intelligently...

2008
Seeing Climate Change Through the Trees
Sarah Kuck reflects on her trip to the Greater Yellowstone Area in Wyoming, and shares a story about how warming temperatures and a changing water balance are upsetting a complex mountain ecosystem, and how the people who love it are using science to save it and maybe the world...

2005
Retro: The Culture of Extinction
Jamais Cascio looks back at Alex Steffen's essay on the Culture of Extinction in which he makes a powerful and moving suggestion: the creation of a living archive of the dead...

Other recent "look backs":
August 24
August 25
August 26