(Click on photos for better view.)
The sign above only stayed up for a few hours in Berkeley, but whoever took it down apparently just needed the bungees and left it behind so I was able to rehang it in San Francisco:
Permafrost is the ancient organic matter in the northern hemisphere's tundra that's been kept frozen for the last 11,000 years and is now, thanks to global warming, beginning to thaw. As it thaws out it releases CO2 and methane into the atmosphere, making the temperatures rise even more, speeding up the thawing process and creating a feedback loop which may well be unstoppable.
The only solution I've been able to come up with so far would be to cover the tundra with vinyl or plastic sheeting and vacuum out the methane before it gets into the atmosphere. This would require the manufacture and placement of thousands of square miles of plastic sheeting - a massive international effort unlikely to happen among governments who so far can't even agree that there's a problem.
In the meantime I'm using cardboard, paint and the freeway system to try and get people thinking. Signs are cheap and easy to make. Kind of fun too, once you get into it... just tracing and painting. Each of these photos represents three or four hours of work.
Any place you can see while driving is a place you can put a sign that'll be read. Just about any fencing you can see can become a billboard just by attaching some cardboard and paint with a couple of bungees.
And it's a hell of a lot of fun.
More info at Freewayblogger.com