Health & Fitness

The influence of human activity in the Arctic on climate and climate impacts

Description
The influence of human activity in the Arctic on climate and climate impacts
Published
of 16
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
Share
Transcript
  The influence of human activity in the Arcticon climate and climate impacts Henry P. Huntington  &  Michelle Boyle  &  Gwenn E. Flowers  &  John W. Weatherly  & Lawrence C. Hamilton  &  Larry Hinzman  &  Craig Gerlach  &  Rommel Zulueta  & Craig Nicolson  &  Jonathan Overpeck  Received: 7 March 2005 /Accepted: 17 May 2006 # Springer Science + Business Media B.V. 2007Climatic ChangeDOI 10.1007/s10584-006-9162-yH. P. Huntington ( * )23834 The Clearing Dr., Eagle River, AK 99577, USAe-mail: hph@alaska.net M. BoyleInstitute for Resources, Environment and Sustainability,University of British Columbia,2202 Main Mall (4th floor), Vancouver, BC V6S 1K4, Canadae-mail: mboyle@ires.ubc.caG. E. FlowersDepartment of Earth Sciences,Simon Fraser University, 8888 UniversityDrive, Burnaby, BC V5A 1S6, Canadae-mail: gflowers@sfu.caJ. W. WeatherlySnow and Ice Division,Cold Regions Research and Engineering Laboratory,72 Lyme Road, Hanover, NH 03755, USAe-mail: weather@crrel.usace.army.milL. C. HamiltonDepartment of Sociology,University of New Hampshire, 20 College Road, Durham, NH 03824, USAe-mail: lawrence.hamilton@unh.eduL. HinzmanWater and Environment Research Center,University of Alaska Fairbanks,P.O. Box 755860, Fairbanks, AK 99775, USAe-mail: ffldh@uaf.eduC. GerlachDepartment of Anthropology,University of Alaska Fairbanks, P.O. Box 757720, Fairbanks, AK 99775, USAe-mail: ffscg@uaf.eduR. ZuluetaDepartment of Biology, Global Change Research Group,San Diego State University,5500 Campanile Drive, PS-240, San Diego, CA 92182, USAe-mail: zulueta@mail.sdsu.eduC. NicolsonDepartment of Natural Resources Conservation,University of Massachusetts,160 Holdsworth Way, Amherst, MA 01003, USAe-mail: craign@forwild.umass.eduJ. Overpeck Institute for the Study of Planet Earth,University of Arizona,715 North Park Avenue, 2nd Floor, Tucson, AZ 85721, USAe-mail: jto@u.arizona.edu  Abstract  Human activities in the Arctic are often mentioned as recipients of climate-change impacts. In this paper we consider the more complicated but more likely possibilitythat human activities themselves can interact with climate or environmental change in waysthat either mitigate or exacerbate the human impacts. Although human activities in theArctic are generally assumed to be modest, our analysis suggests that those activities mayhave larger influences on the arctic system than previously thought. Moreover, humaninfluences could increase substantially in the near future. First, we illustrate how past human activities in the Arctic have combined with climatic variations to alter biophysicalsystems upon which fisheries and livestock depend. Second, we describe how current andfuture human activities could precipitate or affect the timing of major transitions in thearctic system. Past and future analyses both point to ways in which human activities in theArctic can substantially influence the trajectory of arctic system change. 1 Introduction Research over the past decade has begun looking beyond fossil fuel use as the sole driver of global climate change, to consider other human and land-use dimensions as well (Rayner and Malone 1998; Lentz 2000; McIntosh et al. 2000). In the Arctic, it is necessary to do the same.Globally, changes in land use have driven changes in vegetation cover, albedo, runoff,and other factors that feed back to climate. Consumption of living resources such as fishand forests has affected food webs, ecosystem processes, and the survival prospects of many species over time. Such large-scale environmental impacts have been the subject of considerable study (e.g., Cone and Ridlington 1996; Redman 1999; Nelson 2000; Jackson et al. 2001; Nabhan et al. 2004). By contrast, most analyses of the arctic climate system ignore or minimize the role of human activities within the Arctic (e.g., ACIA 2005). Human drivers of directional climatechange and its impacts are considered exogenous to the Arctic, and arctic humans are seensimply as the recipients of impacts. In this paper we broaden that view by examiningseveral ways that human activity in the Arctic influences large-scale biophysical systemsincluding climate itself, and also modifies the impacts of climate change. First, we look tothe past to show how human activities have interacted with climate to impact biophysicalsystems, using examples from fisheries and grazing. Second, we look to the future todescribe how current and future human activities could precipitate or affect the timing of major transitions in the arctic system. We conclude that, in the Arctic as elsewhere, theactive role of humans should play a central part in the analysis of climate-change impacts.The arctic climate system has changed dramatically in recent decades across much of theArctic. The manifestations include reduced summer sea-ice cover, ice sheet and glacier mass loss, permafrost warming, shoreline erosion, increased river runoff, changing oceancirculation, northward-shifting ranges of animals and vegetation  –   and of course,widespread but not universal rising temperatures (Serreze et al. 2000; Hinzman et al.2005; ACIA 2005). Both climate change and the associated shifts in distributions of  weather events are of great concern to arctic residents (Krupnik and Jolly 2002; ACIA2005) and to the broader global society (IPCC 2001a, b) because they force short and long- term adjustments in behavior that interact at multiple scales. As resource extraction effortsintensify around the Arctic (e.g., Nellemann et al. 2001), more infrastructure and newindustrial enterprises are being built in the region. As the arctic biophysical system Climatic Change  approaches sensitive transitions such as the deterioration of permafrost, human decisionsabout natural resource use will play an increasingly important role in determining futuretrajectories of change in the Arctic.Although human activity in the Arctic can exacerbate climate impacts, it is not the onlyor even the main anthropogenic driver of large-scale environmental change in the region.Other drivers lie outside of the Arctic, but activism by arctic residents could be an important form of social feedback. The case of persistent organic pollutants provides one example.Inuit and other arctic indigenous peoples pushed hard for global restrictions, and their efforts were in part responsible for the conclusion of the Stockholm Convention of 2001(Downie and Fenge 2003). Whether arctic peoples will attempt similar levels of activismwith regard to climate change, and with what success, is beyond the scope of this paper. 2 Human influence in the past Climate and human activities interact dynamically. The synergistic results of suchinteraction particularly affect biophysical systems (e.g., Jackson et al. 2001). Too often, policy decisions concerning resource management are based on an assumption of a constant environment with a single variable of change. For example, they may assume that the onlysignificant influence on species abundance is manipulation by humans through harvests or other means (Costanza et al. 2001; Fitzsimmons 1999). Similarly, many assessments of  arctic climate change impacts assume that climate is the single variable of change and that local and regional human activity is a passive recipient rather than a dynamic influence inits own right (ACIA 2005).As the following examples show, such views are simplistic. A better schematic model isgiven in Fig. 1, which shows climate and human influences combining to produce biophysical outcomes. Central to this model is the idea that decisions affecting humanactivities function like a dial, the position of which determines the impacts of physical-environment change. In other words, human decision is a key variable in determining wherea given outcome will fall in the range of potential impacts.2.1 The Newfoundland cod fisheryOnce among the world ’ s richest fisheries resources, Atlantic cod ( Gadus morhua ) off theisland of Newfoundland shaped European settlement and Newfoundland society for 500 years (Sider  1986; Sinclair  1988; Candow and Corbin 1997). During those centuries, fishing technology and effort increased slowly, having incremental and hard-to-perceiveeffects on the resource (Hutchings and Myers 1995). In the decades after World War II,however, technology and fish-catching capacity leaped forward and cod came under new pressure from industrialized trawler fleets. Canada ’ s declaration of a 200-mile economicexclusion zone (EEZ) in 1976 ostensibly cut back fishing by foreign fleets, but Canadiandomestic capacity soon built up to compensate. Signs of depletion were observed andreported by fishermen by the early 1980s, but were not officially acknowledged until thelate 1980s when it was probably too late to prevent a collapse of both the fishstock and thefishery (Finlayson 1994; Hamilton et al. 2004). By the early 1990s, as cod biomass fell to 1% of its earlier level, the crisis became publicand undeniable. Facing ecological collapse on a historically unprecedented scale, theCanadian federal government declared a moratorium on cod fishing. On land, the Climatic Change  Fig. 1  Types and strengths of human-climate interactions and their consequences for the timing of an impact reaching a particular level or threshold ( horizontal dashed line ). ( a ) Climate ( C  ) and humans (  H  ) interact linearly to create a biophysical outcome (  BP  ) with an accelerated threshold crossing. ( b ) Climate and humansinteract nonlinearly in an oscillating system (e.g., fisheries). Human activity amplifies impacts and athreshold is crossed. ( c ) Climate and humans interact nonlinearly in the same oscillating system, but humanactivity is moderated and the threshold is not crossedClimatic Change  moratorium affected tens of thousands of Newfoundland workers, and underminedhundreds of coastal communities (Candow and Corbin 1997; Palmer and Sinclair  1997; Harris 1998; Hamilton and Butler  2001). While federal interventions softened the short- term social consequences, the populations of many fishing ports grew smaller, older, andmore dependent on federal assistance, conditions that continue to this day (Hamilton andButler  2001; Hamilton et al. 2004). The cod fishery itself showed little sign of recovery even a decade after the moratorium (Haedrich and Hamilton 2000).Biological analyses are explicit about overfishing as the primary cause for the collapseof cod and other groundfish around Newfoundland (Hutchings and Myers 1994; Sinclair and Murawski 1997), and were so even prior to official recognition of the collapse. But the physical environment was worsening as well, another important contributor to the collapse(Drinkwater  2002). Unusuallycold,icyconditionsoccurredoffnorthandeastNewfoundlandduring the 1980s and 1990s, resulting from strong northerly winds associated with a prolonged positive state of the North Atlantic Oscillation. The cold intermediate layer (CIL)of the Labrador Current became more extensive during the early 1990s (see Fig. 2). Colder conditions, however, need not be fatal to north-adapted species. Using data from theLabrador Sea, Fischer and Haedrich (1999) demonstrated that even during the coldest yearsin the Labrador Sea, the distribution of dangerously cold water was patchy and left muchsuitable habitat available for groundfish.Historically, Newfoundland ’ s groundfish have survived other cold periods without collapse. By the 1980s, however, decades of fishing had effectively altered marineecosystem structure and function through removal of many of the larger, older fish. Their removal left fish populations less reproductively robust (because older females producemore eggs and more viable offspring) at the same time that the fishery became increasinglydependent on constant recruitment of young fish. Colderconditions slowed growthrates andreduced recruitment directly, which in turn exacerbated the impacts of fisheries removals andaccelerated the vicious circle of dumping smaller-size fish. The result is a clear example of how human activities interact with climate to precipitate disastrous ecological collapse.2.2 The Bristol Bay, Alaska salmon fisheryA contrasting case is that of salmon ( Oncorhyncus  spp.) in Bristol Bay, Alaska, in the1990s. The Bristol Bay fishery has harvested an average of more than 25 million salmonannually since the late 1970s (see Fig. 3), though with considerable interannualvariability. In 1997, however, the salmon returns were far below the expected levels. Incontrast to the poorly considered Newfoundland response, the managers of the Bristol Bayfishery closed the fishery as soon as the slow return was detected at fish counting stations inthe region (ADF&G 1998). This in-season management decision was based on the lownumber of fish and the late timing of the run, both of which did not match historical patterns for strong fish returns. The 1997 harvest was only 40% of the 1996 harvest (whichin turn was only 2/3 the record harvest of the previous year), and the 1998 harvest was evenlower (ADF&G 1999). In previous years, fish size and run size were typically inverselycorrelated, whereas in 1997 both were small, suggesting the possibility of oceanographiccauses for the low return (Kruse 1998).In 1999, the harvest returned to the range of the historical average, and remained there in2000. The Marine Stewardship Council, a non-governmental organization that certifiesfisheries around the world as  ‘ sustainable ’ , awarded certification to the Bristol Bay fishery inSeptember 2000 (http://www.msc.org/html/content_485.htm), indicating strong confidence Climatic Change
Search
Similar documents
View more...
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks
SAVE OUR EARTH

We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

More details...

Sign Now!

We are very appreciated for your Prompt Action!

x