notably contrasts with that of the Kyoto Protocol, which primarily focuses on reducing emissions emanating from developed countries.¶ Despite these and other marked successesduring the COP-17, the perceived lack of leadership by central players in the climatechange debate—especially the United States—has elicited increasing concern about the longterm prospects of the global climate change regime.Additionally, Canada's December 2011 decision to withdraw from the Kyoto Protocol—based on domestic economic concerns as well as its view that the world's top greenhouse gas emitters have refused to ratify the accord—has generated concerns that the Kyoto Protocol itself may be in danger ofcollapse. Both of these concerns and many other issues will likely be a part of the agenda for the COP-18, scheduled for November 2012 in Qatar.We’re reaching a tipping point – action now is critical to prevent positive feedbacksHansen 2009, heads the NASA Goddard Institute for Space Studies and adjunct professor in the Department of Earth and Environmental Sciences at Columbia University (James, December, Storms of My Grandchildren, 72-74)Ice sheet response to global warming is quite the contrary. Ice sheet size changes little at first, and thus sea level changes only slowly. As the planet gets warmer, the area on the ice sheet with summer melt increases. And as the ocean warms, ice "shelves"—tongues of the ice sheet that reach out into the ocean and are grounded on the ocean floor—also begin to melt. Asice shelves disappear and the ice sheet is "softened up" by surface warming and meltwater,movement of ice and discharge of giant icebergs via ice "streams" become more rapid, leading to thepossibility that large portions of the ice sheet will collapse.If we continue burning fossil fuels atcurrent rates, ice sheet collapse and sea level rise ofat leastseveral meters is a deadcertainty. We know this from paleoclimate records showing how large the ice sheetswere as a function of global temperature. The only question is how fastice sheet disintegration will occur.Once ice sheets begin to collapse, sea level can rise rapidly. For example, about 14,000 years ago, as Earth emerged from the last ice age and became warmer, sea level rose at an average rate of 1 meter every 20 or 25 years, a rate that continued for several centuries. The danger today is that we may allow ocean warming and "softening up" of ice sheets to reach a pointsuch that the dynamical process of collapse takes over. And then it would be too late—we cannot tie a rope or build a wall around a mile-thick ice sheet.The third source of inertia is our fossil-fuel-based energy system.
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