What would it take to level off the carbon dioxide in the atmosphere at 450 parts per million (ppm)? That level supposedly would keep global warming just barely manageable at an increase of 2 degrees Celsius. There still would be massive loss of species, 100 million climate refugees, and other major stresses. The carbon dioxide level right now is 385 ppm, rising fast. Before industrialization it was 296 ppm. America’s leading climatologist, James Hansen, says we must lower the carbon dioxide level to 350 ppm if we want to keep the world we evolved in.
The world currently runs on about 16 terawatts (trillion watts) of energy, most of it burning fossil fuels. To level off at 450 ppm of carbon dioxide, we will have to reduce the fossil fuel burning to 3 terawatts and produce all the rest with renewable energy, and we have to do it in 25 years or it’s too late. Currently about half a terrawatt comes from clean hydropower and one terrawatt from clean nuclear. That leaves 11.5 terawatts to generate from new clean sources.
http://www.azimuthproject.org/azimuth/show/Saul+Griffith#climate_change_recalculated_3
James Hansen, who is quoted in that article, claims that "changes needed to reduce global warming do not require hardship or reduction in the quality of life, but will also produce benefits such as cleaner air and water, and growth of high-tech industries" (http://en.wikipedia.org/wiki/James_Hansen#cite_note-53). I remain very confused as to why everyone seems convinced that stopping climate change is a hopeless cause.
... the general take on climate change here.
Please read a little more before voting this down - I am not looking to initiate a debate on climate change - merely to understand what goes on when it is mentioned.
Disclosure: I am personally concerned about the impact of climate change in the medium term; I am largely convinced it is caused by human activity; I can get moralistic about it. I won't push any of that in this discussion.
I am a relatively recent habituee of the these fora, and mostly I find it full of entertaining, intelligent people talking thoughtfully about things that interest/concern me. I'm pleased - this is rare. Thanks, all.
I searched for mentions of climate change, and read some threads. I got the impression that a majority viewpoint here was that it is not an issue that concerns people here. I got the further impression that it is an issue which arouse feelings of irritation or worse in a significant minority of people here.
Neither of these impressions were strong enough to give me any useful level of certainty, though.
So I thought Will Newsome's wonderful Irrationality Game post might help me with an experiment.
I posted the following:
"Human activity is responsible for a significant proportion of observable climate change. 90% confidence"
I expected (in the topsy turvy context of that post) to get UPvoted, as I assumed a majority of viewers would disagree. I hoped to see some comments which would help clarify my weak impressions.
In fact, I got downvoted (-7), suggesting fairly significant agreement. At the same time, the comment is invisible (to my attempts) in the list of comments to the post, leading me to suspect that it has been removed by a moderator (perhaps on the grounds that CC is viewed as 'political'?).
Can anyone help me? I do not intend to use anything here as a platform for pushing an agenda - I'd just like to understand.