I don't know if the earth is in trouble from human activity. I don't know if the earth is gradually warming. I haven't seen Al Gore's movie.
One person said that 30 years ago, we would have been worried about a possible new Ice Age, and that long-term changes are difficult to detect given the long-term fluctuations that happen in a dynamic system with so many variables. Makes sense.
I saw a segment on 60 Minutes where a former NASA investigator showed the report he submitted on climate change citing scientific evidence on the causes and possible remedies of what he thought was happening. Then he showed the handwritten edits that a
lobbyist for the petroleum industry
Bush administration official (former lobbyist) had mandated in the manuscript, such as changing phrases like "is" to "may be."
When asked what the industry lobbyist's qualifications were, the answer was that he had no degree or expertise in science. I remember when a group of concerned citizens met with a representative of the Department of Energy regarding the Hanford nuclear waste disposal problems of leaky tanks and proximity to the Columbia River. After an evening meeting set to reassure the residents, one attendee said to the TV news interviewer, "I would've been a lot more confident in the information if he knew how to pronounce nuclear."
When asked what the NASA investigator's scientific background was, the answer was "rocket scientist."
It's not that they are trying to determine the hard cold scientific evidence when they make those policy changes, however. What saddens me is that they are not trying to find the truth, just steering the facts to a predetermined conclusion.
An interesting sidenote is that one of the largest funders attacking the message of global warming is the tobacco industry. It's in their interest to cultivate doubt and skepticism.