global warming
It is pretty amazing the way that a very small group of dissidents, paid by energy interests, have managed to grab control of the media and convince the bulk of the public that 99% of the world's scientists dont know what they are talking about. It just shows how little power scientists have.
I was a sceptic (of course) when I first encountered the climate change literature while I was working for CSIRO in 1990. Pearman, head of Atmospheric Research at the time, convinced me very easily. He just said, look the CO2 in the air has doubled in the past 100 years due to human activity, it HAS to be causing an increased greenhouse effect. The only question is, how much and what are all the complicating factors.
Before there were plants on earth, the CO2 levels in the air were very high. It has been sequestered in the ground by hundreds of millions of years of plant decay. A plague of humans pulling it up and putting it back in the air is going to have a global effect. The obvious effect is slow warming and an alteration of the world's weather patterns - which because they are choppy and other things are affecting them are hard to spot decisively. However 5 of the hottest global years on record since 1990, and the melting of the equatorial glacier fields, is pretty indicative.
When I say the CSIRO guys are being responsible I mean it. Yes they can decisively say there is warming due to anthropomorphic CO2 emissions - other things being equal. No, after only about 25 years of vaguely looking at this and 15 years of seriously looking, in such a noisy system you cant yet decisively separate the CO2 effect from other things that might be going on. We still havent decisively proven Einsteins general relativity theory yet either, after 70 years.
