On the original topic- I think Blast has it pretty much right with his MIB quote. There is always something or signs of something going on that could or might be happening. We are suffering from a serious infliction of instant "news" across a global scale. It used to be news took longer to travel and cost more to transmit so people were blissfully unaware, each tech revolution has impacted the flow time and costs so we get more "bad news", faster.

On the issue of the current climate concerns, my understanding is that all of the most current science on climate change is based on relatively simple models of the environment (they are actually quite complex but simple compared to reality) fed by a statistically insignificant amount of actual data (realistically we only measure a tiny fraction of the possible environmental data). These models are run a whole lot of times on supercomputers with the inputs of each run fed by the outputs of the last run. This may be the best we can do but my concerns are best defined by a distinguished gentleman named George Box, who said that "all models are false but some models are useful". The people generating and using the models hopefully recognize they are false and the debate seems to revolve around a disagreement in how useful they are. I would guess that most people on either side of the public (non-scientific) debate do not have extensive backgrounds in numerical analysis, modeling of complex systems, climatology etc. so the debate is driven by other factors.

For what it is worth - I am not a climate expert but I work a lot with modeling complex systems (that are trivial by comparison to the earths climate). All of our models are for safety critical stuff but none of us trust them without out actual in the field testing. That could be a bit of a challenge for those working on climate models!

- Eric