consensus
so 97% of climatologists believe in agw. so what does that mean exactly? it means they agree with the following three statements: 1) the world has been getting warmer for at least the past 150 years. 2) human activities account for a significant* part of that warming. and 3) co2 in the atmosphere warms the earth via the greenhouse effect. as near as i can tell, significant is sorta loosely defined. it could be anywhere from 2% to 200%. heh. how the heck could it be 200%? that's absurd. heh. not really. some models predict the earth should be cooling at the rate it's heating. so something has negated the cooling. and on top of that, done the heating. anywho. the ipcc model has several additional parts. 4) there's a positive feedback amplification factor of 3-5. ie a little heating causes more heating causes more etc. there's an implied 4a) that 4) will go on for a significant period of time. and 5) warming is bad for humans. buy-in for 1) is nearly 100% among people who actually study this topic. cause it's supported by data. lots and lots of data. the buy-in rate generally drops as you progress. re 2), it's abundantly clear that humans are changing the environment. and that changing the environment can change the weather. and hence the climate. ergo, it's nearly certain humans are at least in part responsible for changes to the climate. caveat: unfortunately, there's no control for this experiment. maybe you religious types could get god to create a sister earth on the other side of the sun where people don't burn fossil fuels. anywho 3) absolutely. again backed up by data. 4) and 4a), earth's climate has been pretty stable for millions of years. if the forcing was really 3-5 over large temperature ranges, one would expect the earth's temperatures to vary a lot more than they do. so either the forcing is less. a lot less. or it depends on other transient factors that happen to be converging right now. the forcing may depend indirectly on temperature. ie when it gets hot, plants die, and the earth stops warming. and then the forcing turns around like a swinging pendulum. ie a little cooling begets more cooling. and BOOM! ice age. and 5) fooey! humans are the most adaptable creatures ever to walk the earth. rapid change is bad for most creatures. they'll die. the remainder will flourish without the competition and/or predators. for people, change is a double edged sword. it means a bunch of stuff we've invested, whether financially or emotionally, will go away. making us sad. change also means that opportunity will be knocking 'til its knuckles are sore and bleeding. me the hippie would like to not change the world on the scale that we are. its beauty is diminished by the things that people do. me the pragmatist is one voice against a consensus of billions.