Carbon dioxide overshoot?

Question

i am familiar with the term overshoot from 'limits to growth' onwards in environmentalism, but in Hansen et al's latest is the first time i have heard it in relation to CO2. sounds scarily plausible to me.

here a quick precis;

http://www.worldchanging.com/archives/007921.html

luckily, i know the proposed answer (change in farming practice, sequestration in soils) is feasible, it has been my main hobby for years.

permaculture and terra preta will save the world.....

Answer 1

Wow 350 ppm.  That's a really difficult goal considering that we've already gone above 380 ppm.  It will take some major changes in how we do basically everything to eventually get the CO2 concentration back down to 350 ppm.

Answer 2

Here's a similar data point, coming from energy measurements, that implies that we're going to need to seriously curb emissions:

"The authors find a planetary energy imbalance that averages almost 1 Watt per square meter, more precisely 0.85 plus or minus 0.15 watts per square meter. The authors note that it would be necessary to reduce greenhouse gas forcing by that amount if it were desired to stabilize climate at today’s global temperature. 'In principle we could do that', says Hansen, 'by halting all anthropogenic methane emissions or by somehow removing half of the humanmade carbon dioxide now in the atmosphere, but that is not practicable in the foreseeable future, so the world is going to become warmer.'”

Earth’s Energy Out of Balance: The Smoking Gun for Global Warming

http://www.columbia.edu/~jeh1/imbalance_...

Answer 3

Good for you.  You're doing something and it makes sense.  You can't make yourself responsible for everyone.