The 21st Century climate challenge

Alaska to Siberia has increased by 3.6°C—morethan twice the global average. Snow cover hasdeclined by 10 percent in the past 30 years,and average sea ice cover by 15–20 percent.Permafrost is melting and the tree line is shiftingnorthwards.Climate change scenarios point in a worryingdirection. Mean surface temperatures areprojected to increase by another 3°C by 2050,with dramatic reductions in summer sea ice, theencroachment of forests into tundra regions, andextensive loss of ecosystems and wildlife. Entirespecies are at risk. As the Arctic Climate ImpactAssessment puts it: “Marine species dependenton sea ice, including polar bears, ice-living seals,walrus and some marine birds, are very likely todecline, with some facing extinction.” 98The United States has acknowledged theimpact of climate change on the Arctic. InDecember 2006, the US Department of theInterior proposed, on the basis of “the bestscientific evidence”, placing the polar bear onthe Endangered Species list. That act effectivelyacknowledges the role played by climate changein increasing its vulnerability—and it requiresgovernment agencies to protect the species. Morerecently, polar bears have been joined on the list by10 species of penguin which are also under threat.Unfortunately, the “best scientific evidence”points in a worrying direction: within a coupleof generations, the only polar bears on the planetcould be those on display in the world’s zoos. Thelate summer Arctic sea ice, on which they dependfor hunting, has been shrinking at over 7 percenta decade since the late 1970s. Recent scientificstudies of adult polar bears in Canada and Alaskahave shown weight loss, reduced cub survival, andan increase in the number of bears drowning asthey are forced to swim further in search of prey.In western Hudson Bay, populations have fallenby 22 percent. 99The United States Department of theInterior’s actions establish an important principleof shared responsibility across borders.That principle has wider ramifications. Polarbears cannot be treated in isolation. They arepart of a wider social and ecological system.And if the impact of climate change andassociated responsibilities of governmentsare recognized for the Arctic the principleshould be more widely applied. People livingin drought-prone areas of Africa andflood-prone regions of Asia are also affected.Applying one set of rules for polar bears andanother for vulnerable people in approachesto climate change mitigation and adaptationwould be inconsistent.The sheer pace of climate change acrossthe Arctic is creating challenges at manylevels. Loss of permafrost could unlock vastamounts of methane—a potent greenhousegas that could undermine mitigation effortsby acting as a driver for ‘positive feedbacks’.The rapid melting of Arctic ice has opened upnew areas to exploration for oil and naturalgas, giving rise to tensions between states overthe interpretation of the 1982 Conventionon the Law of the Sea. 100 Within countries,climate change could lead to immense socialand economic harm, damaging infrastructureand threatening human settlements.Scenarios for Russia illustrate the point.With climate change, Russia will experiencewarming effects that could raise agriculturalproduction, though increased exposure todrought may negate any benefits. One of themore predictable consequences of climatechange for Russia is increased thawing of thepermafrost which covers approximately 60percent of the country. Thawing has alreadyled to increases in winter flows of majorrivers. Accelerated melting will affect coastaland river bank human settlements, exposingmany to flood risks. It will also require heavyinvestments in infrastructural adaptation,with roads, electrical transmission lines andthe Baikal Amur railway potentially affected.Plans are already being drawn up to protect theplanned East Siberia–Pacific export oil pipelinethrough extensive trenching to combat coastalerosion linked to permafrost melting—afurther demonstration that ecological changecarries real economic costs. 101The coral reef—a climate changebarometerArctic regions provide the world with a highlyvisible early warning system for climate change.The “best scientificevidence” points in aworrying direction: withina couple of generations,the only polar bears on theplanet could be those ondisplay in the world’s zoos2Climate shocks: risk and vulnerability in an unequal worldHUMAN DEVELOPMENT REPORT 2007/2008 103