Methane released by thawing tundra and Arctic seeps may create a self-reinforcing feedback cycle that could result in abrupt climate change. This has happened in the past, as evidenced geologically.
An article at Common Dreams by Gary Houser explores this frightening idea
Humans expect the future to resemble the immediate past. What if it doesn't?
Here is an excerpt:
"Those who follow this issue likely have familiarity with the concept of "tipping points". This innocuous-sounding phrase does not do justice to its vast meaning. It refers to the crossing of a line whereby tremendous natural forces are unleashed and an unstoppable rush of interlocking climate disruptions wreak havoc on the earth and its fragile web of life-supporting ecosystems. Once set in motion, it cannot be predicted how far the devastation would extend. Geological records have linked a severe climate shift with the "Great Extinction" event which wiped out a ghastly 90% of all life forms on the planet. "
Majia here: I do not know how imminent this threat is; however, after the handling of the disaster wrought by Katrina and now the Gulf also, I am confident that our government will not act to protect the people or the long term viability of the nation.
The biggest threat from climate change is FOOD SCARCITY. Our food supply chains are very vulnerable. Already, global food demand risks outstripping supply. Any vulnerabilities in our food supply chains will result in food shortages.
Any abrupt climate change--up or down in temperatures--will compromise our food supply. This is a real threat and our government appears to be doing nothing to address it.