stephen_schneider's picture
climatologist, is a professor in the Department of Biological Sciences

Scientists have been talking about the risks of human induced climate changes for decades now in front of places like Congress, scientific conventions, media events, corporate board rooms, and at visible cultural extravaganzas like Live Earth. Yet, a half century after serious scientific concerns surfaced, the world is still far from a meaningful deal to implement actions to curb the threats by controlling the offending emissions.

The reason is obvious: controlling the basic activities that brought us our prosperity—burning fossil fuels—is not going to be embraced by those who benefit from using the atmosphere as a place to dump for free their tailpipe and smokestack effluents, nor will developing economies like China and India easily give up the techniques we used to get rich because of some threat perceived as distant and not yet certain. To be sure there is real action at local, state, national and international levels, but a game changing global deal is still far from likely. Documented impacts like loss of the Inuit hunting culture, small island states survival in the face of inexorable sea level rise, threats of species extinction in critical places like mountain tops, or a five fold increase in wild fires in the US West since 1970 have not been game changin—yet. What might change the game?

In order to give up something—the traditional pathway to wealth, burning coal oil and gas—nations will have to viscerally perceive they are getting something—protection from unacceptably severe impacts. The latter has been difficult to achieve because most scientific assessments are honest that along with many credible and major risks are many remaining uncertainties.

We cannot pin down whether sea levels will rise a few feet or a few meters in the next century or two—the former is nasty but relatively manageable with adaptation investments, the latter would mean abandoning coastline installations or cultures where a sizeable chunk of humanity lives and works. If we could show scientifically that such a threat was likely, it would be game changing in terms of motivating the kinds of compromises required to achieve the actions needed that are currently politically difficult to achieve.

This is where the potential for up to 7 meters of sea level rise stored as ice on Greenland will come in to tip us toward meaningful actions. Already Greenland is apparently melting at an unprecedented rate, and way faster than any of our theories or models predicted. But it can be—and has been—argued it is just a short term fluctuation since large changes in ice volume come and go typically on millennial timescales—though mounting evidence from ice cores says probably there is unprecedented melting going on right now. Another decade or two of such scientifically documented acceleration of melting could indeed imply we will get the unlucky outcome: meters of sea level rise in the time frame of human infrastructure lifetimes for ports and cities—to say nothing of vulnerable natural places like coastal wetlands etc.

Unfortunately, the longer we wait for more confident "proof" of game changing melt rates in Greenland (or West Antarctica as well, where another 5 meters potential sea level rise lurks), the higher the risk of passing a tipping point in which the melting becomes an unstoppable self-driven process. That game change occurrence would force unprecedented retreat from the sea, and a major abandonment or rebuilding of coastal civilization and loss of coastal wetlands. This is a gamble with "Laboratory Earth", that we can't afford to lose.