Added pine beetle forest kill and permafrost melt.

I guess John deleted the "2000s vs. 1950s drought" diagram by accident?

Diagram resurrected, plus 4 images of pine beetle damage and permaforst melt added.

_Is it OK to have so many images?_

The permafrost images are particularly breath taking. As the wiki parser couldn't take the original URLs I found out how to get the biggest pictures (bigger than the source manages to serve clickably). _Don't miss clicking the links to these!_

Next time I got time: Yummy pics of burning forest. (If it's OK...)