Neglected Ice Sheets Water Down IPCC Report
Wednesday, January 31st, 2007
The report hasn’t even been released yet, but one of the big stories around this Friday’s release by the Intergovernmental Panel on Climate Change (IPCC) is the conservative edge to the final product, which does not fully account for the melting of the Greenland nor Antarctic ice sheets.
The report is consensus-based and as such, carefully written and meticulously reviewed. The process is heavily bureacratic, a maze of international political and scientific red tape, which is both its strength and weakness.
While its level of international cooperation attests to its conclusions, scientists have struggled with how to model variables like melting ice sheets. Taking into consideration the Greenland and Antarctic ice sheet is likely to move measurements of the sea level rise from inches to feet or meters within this century.
Uncertainties in the science need to be addressed with more research, certainly not the proposed cutback in funding for climate studies. And for as cautious as the IPCC report is in its creation, it needs to consider and calculate the potential consequences of climate change even more cautiously.
That means at least two things need to accompany the report’s release: a public awareness campaign of the missing pieces and future IPCC reports that include models of disintegrating ice sheets.
Posted in Climate Progress | 1 Comment »
Chapter Five Excerpt: How Climate Rhetoric Trumps Climate Reality
Tuesday, January 30th, 2007
The scientific debate is closing (against us) but not yet closed.
–Frank Luntz, conservative strategist, 2002
Global warming is real (conservatives secretly know this).
–David Brooks, New York Times columnist, 2005
The global- warming problem is no longer primarily a scientific matter. Science has told us what we need to know about how life on this planet will be ruined if we stay on our current greenhouse gas emissions path. Global warming is also not a technological problem. We have the technologies to avoid the disasters that await us if we keep doing nothing.
Today, global warming is a problem of politics and political will. We lack the will to take the necessary actions–and many of the actions we are poised to take are either inadequate or ill conceived. The great political tragedy of our time is that conservative leaders in America have chosen to use their superior messaging and political skills to thwart serious action on global warming, thereby increasing the chances that catastrophic climate change will become a reality.
Global warming should not be a partisan issue–not when the health, well- being, and security of the next fifty generations of Americans are at stake. But it has become partisan, at least in this country. In order to determine how to create the politics of action in the next decade, we must understand what the politics of inaction has caused in the past decade. That’s what this chapter is about.
Posted in Climate Progress | 2 Comments »
A Rise in the Rise of Sea Levels
Monday, January 29th, 2007
A new “semi-empirical” method of estimating sea level rise shows that earlier techniques underestimated the likely rise, according to research published in Science online.
Ocean expert Stefan Rahmstorf noticed a correlation between the warming in the atmosphere and the rise of sea levels over the 20th century. Having also watched the actual rate of sea level rise pass earlier computer estimates, Rahmstorf integrated his real-world observations with the models.
Rahmstorf estimates a possible sea level rise of anywhere from 50 to 140 centimeters, up from 9 to 88 cm. The new numbers would put North Atlantic shore cities, like New York and London, at higher risk for storm surges, which helped flood New Orleans.
Rahmstorf’s research has higher accuracy than previous models, explaining why he insists that:
We should not take this risk. We should start with very effective emission reduction measures. The global temperature increase should be kept to under 2°C.
Already, we have experienced a .8°C increase, meaning we are almost halfway to where scientists have warned us not to go, and we need to stop pushing the envelope.
Posted in Science | 2 Comments »
Chapter Four Excerpt: The Hell and High Water Scenario
Saturday, January 27th, 2007
We could get a meter [of sea-level rise] easy in 50 years.
– Bob Corell, chair, Arctic Climate Impact Assessment, 2006
The peak rate of deglaciation following the last Ice Age was . . . about one meter [39 inches] of sea- level rise every 20 years, which was maintained for several centuries.
– James Hansen, director, Goddard Institute for Space Studies (NASA), 2004
Sea-level rise of 20 to 80 feet will be all but unstoppable by midcentury if current emissions trends continue. The first few feet of sea-level rise alone will displace more than 100 million people worldwide and turn all of our major Gulf and Atlantic coast cities into pre-Katrina New Orleans–below sea level and facing superhurricanes.
How fast can seas rise? For the past decade, sea levels have been rising about 1 inch a decade, double the rate of a few decades ago. The Third Assessment Report of the U.N. Intergovernmental Panel on Climate Change (IPCC), released back in 2001, projected that sea levels would rise 12 to 36 inches by 2100, with little of that rise coming from either Greenland or Antarctica. Seas rise mainly because ocean water expands as it gets warmer, and inland glaciers melt, releasing their water to the oceans.
Sea-level rise is a lagging indicator of climate change, in part because global warming also increases atmospheric moisture. More atmospheric moisture probably means more snowfall over both the Greenland and Antarctica ice sheets, which would cause them to gain mass in their centers even as they lose mass at the edges. Until recently, most scientists thought that the primary mechanism by which these enormous ice sheets would lose mass was through simple melting. The planet warms and ice melts–a straightforward physics calculation and a very slow process, with Greenland taking perhaps a thousand years or more to melt this way, according to some models.
Since 2001, however, a great many studies using direct observation and satellite monitoring have revealed that both of the two great ice sheets are losing mass at the edges much faster than the models had predicted. We now know a number of physical processes can cause the major ice sheets to disintegrate faster than by simple melting alone. The whole idea of “glacial change” as a metaphor for change too slow to see will vanish in a world where glaciers are shrinking so fast that you can actually watch them retreat.
The disintegration of the Greenland and Antarctic ice sheets is a multistage process that starts with the accelerated warming of the Arctic….
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