It’s difficult to remain optimistic when “the most comprehensive survey into the state of the planet concludes that human activities threaten the Earth’s ability to sustain future generations.”
On the other hand, at least the report exists.
(I’ll form more of an opinion once I’ve read the report, which you can download online in PDF format.)
(via BBC News: “Study highlights global decline,” by Jonathan Amos [March 30, 2005]; see also the CSM editorial, “Heading off Eco-Armageddon”)