As I've said before, the international community has just a few years to agree to, engineer, and implement a full solution. We're expected, on our current course, to hit 650 ppmv CO2 by 2100. That's without all possible feedbacks included, such as methane release from the ocean bottom, or sudden and complete melting of the permafrost.
If we can't even agree to our limits until 2020, there is no possibility of reducing them enough to avoid 2 or 3 degrees C warming. I've hinted at problems associated with various warming scenarios before, but here are a few that we are going to see. Not "might" see, but going to see because of the failures of vision at the Copenhagen summit.
This is what's going to happen as we hit 2 degrees C warming, which was avoidable ten years ago, mostly avoidable five years ago, and is completely unavoidable now:
- Dramatic changes to weather patterns worldwide
- Elimination of fresh water for 1/3 of world's land surface
- Permanent drought in US southwest, Australia, and Africa
- Much of inner Australia will burn
- Aquifer levels under the US Great Plains, Saudi Arabia, and Northern China are falling fast, without replenishment.
- Rise of sea levels by at least 1.2 meters (2.75 billion people affected)
- Food & water shortages will cause unstable States to fail:
- African states, Pakistan*, North Korea*, Somalia, Iraq,
- India*, China*, Afghanistan, Israel* Sudan, Lebanon*, ...
- 1 degree of warming: wheat, corn, rice yields drop 10%.
- Global food reserve was at less than 62 days and declining in 2008.
- Disease epidemics will become worse and last longer
- Over-Consumption is worse than high population.
At 3 or more degrees C warming, we will see the following (in fact, some of this is happening already--we don't fully understand all of the feedback mechanisms):
- At or above 2 degrees of warming, positive feedback systems become active.
- Permafrost will begin to melt more quickly, releasing CO2.
- Methane will be released from the seafloor bottoms, adding more GHG to atmosphere.
- Composting rate of organic matter increases, CO2 release.
- Amazon forest, grasslands die & burn, releasing CO2.
- Plants begin to release CO2 instead of absorbing it.
- At 3 degrees warming, run-away permafrost melting will begin, releasing more and more CO2.
- 3-4 degrees warming is avoidable if we cut emissions by 80% by 2020.
- At 6 degrees warming, hydrogen sulfide gas makes up a large part of the atmosphere.
- We will hit 5-7 degrees of warming by 2100 at current emission growth rate of CO2.
So, let me just say, son, that while we love you, we didn't think your future is important enough to protect by sacrificing any of our own comfort. Sorry. We hope that some of you will forgive us, but understand if that's difficult to do. Also, those morons who thought it would be a good idea to dump billions of tons of chalk into the oceans in 2025? We didn't do anything to stop them because, well, we just couldn't be bothered.
[edit]
See this video of a talk at AGU last week.
http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml#