Yes the earths temperature seems to be rising, but I don't think we know enough to put the blame on our CO2 emissions. Around 1000AD the vikings were settling greenland and the average temperature was 2-3 degrees Celsius higher than today. Then around 1350 AD we went into the little ice age which we didn't start coming out of until the early 20th century.
As for Lester Brown, he has been predicting the end of the world for decades. Its what he does. If he didn't yell the sky is falling all the time nobody would donate money to his organization. Just because he claims to represent the environment, doesn't make him ethical or unethical. I wonder if he tells people the most significant greenhouse gas by far is water vapor.
And I disagree with his depiction of the hurricane katrina victims as climate refugees. Since no respectable climatoligist (even those who believe in global warming) would attribute a specific storm to global warming, they are hurricane refugees. But he won't call them that because it doesn't back up his claims.
