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PLANNING IN THE CONTEXT OF CLIMATE CHANGE: INSIGHTS FROM RECENT WARMING IN ALASKA F. STUART CHAPIN, III, NANCY FRESCO, T. SCOTT RUPP AND SARAH F. TRAINOR UNIVERSITY OF ALASKA FAIRBANKS

Since 1970, Earth’s climate has warmed more rapidly than at any time in the last several hundred years. This is largely due to human emissions of heat-trapping gases such as carbon dioxide (CO2). The CO2 already emitted to the atmosphere commits the planet to several centuries of continued warming, although the rate of this warming depends on future rates of CO2 emissions. In addition, dry regions such as the southwestern United States and the continental interior of Canada and the U.S. will likely become drier due to more frequent droughts, while wet regions (e.g., the northwestern U.S. and western Canada) will likely become wetter due to more frequent heavy rains and floods. Planners have an opportunity to reduce society’s vulnerability to climate change by planning in the context of these ongoing trends, given that their continuation is more likely than a return to climate conditions we have known in the past. Even if climatic changes are slower or less pronounced than scientists predict, planning is still useful to reduce society’s vulnerability to extreme events. For example, planning that reduces vulnerability to what was historically a 100-year flood but which may in the future occur every 10 to 20 years reduces a community’s vulnerability, regardless of how quickly this flood pattern changes. Climatic warming is occurring more rapidly in the North than at lower latitudes, so recent changes in Alaska provide

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insights into the types of vulnerabilities that will likely develop in coming decades in more southerly locations. Air temperatures in Alaska have warmed in the last 50 years by 1.9 C (3.5 F) and are expected to rise by a similar amount by 2050. In other words, the average temperature in 2050 will be similar to temperatures seen only in the warmest years half a century ago. Everybody can remember what an extremely warm or cold (or wet or dry) year is like and should therefore be able to relate to the magnitude of climatic changes already occurring in Alaska. Although warmer temperatures have important direct effects, including more extreme heat waves and less fuel required for winter heating, the indirect effects of warming have even greater impacts on Alaska. Due to its cold climate, much of Alaska is underlain by permafrost (permanently frozen ground), which often has a relatively high ice content—50 per cent of soil volume or more. When permafrost thaws, ice turns to water and the ground surface subsides unevenly, causing roads and foundations to buckle and electrical transmission poles to tilt or fall. Airport runways, a key lifeline in Alaska’s remote, roadless communities such as Naknek, now require frequent— sometimes annual—regrading to remain open to air traffic. The proportion of Alaska where soil temperatures have risen above freezing has already increased substantially and will likely continue to do so in the next 50 years, creating very different

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planning requirements for the siting of roads, airports and other infrastructure. Thawing permafrost is expected to increase the cost of maintaining public infrastructure by 10 to 20 per cent by 2030. Warming also increases the risk of extreme events. The area burned by wildfires in interior Alaska and boreal Canada has tripled from the 1960s to the 1990s, with comparable or greater increases expected by 2050; this poses significantly greater fire risks to communities as well as greater costs to fire management agencies. The warminginduced shrinking of sea ice on the western and northern coasts of Alaska exposes many coastal villages to storm surges that erode homes into the ocean and, in some cases, will require complete relocation of communities. For example, Newtok experienced six extreme weather events between 1989 and 2006, damaging critical infrastructure such as power distribution, water and septic systems, and fuel storage tanks. Five of these events precipitated presidential disaster declarations. Human-induced climate change is occurring and is likely to continue. If climate trends and projections had guided planning in Alaska over the last 50 years, the psychological, social and economic costs might have been less extreme. Communities elsewhere have an opportunity to learn from Alaska’s experience and to integrate climate change into their planning processes, as New York

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CURB Magazine 3.1  

Curb Magazine is about policy practice and community experiences in cities, regions, and rural areas. Curb is distributed to municipal offic...

CURB Magazine 3.1  

Curb Magazine is about policy practice and community experiences in cities, regions, and rural areas. Curb is distributed to municipal offic...

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