Maine Confronting Climate Change in the U.S. Northeast rom towering Mount Katahdin to the unavoidable changes that past emissions have sandy beaches of York, the climate of already set in motion. Maine is changing. Records show that spring is arriving earlier, summers are MAINE’S CHANGING CLIMATE growing hotter, and winters are be- Temperature. Average temperatures across the coming warmer and less snowy. These Northeast have risen more than 1.5 degrees Fchanges are consistent with global warming, an Fahrenheit (°F) since 1970, with winters warm- increasingly urgent phenomenon driven by ing most rapidly—4°F between 1970 and 2000. heat-trapping emissions from human activities. If higher emissions prevail, seasonal average New state-of-the-art research shows that if temperatures across Maine are projected to rise global warming emissions continue to grow 10°F to 13°F above historic levels in winter and unabated, Maine can expect dramatic changes 7°F to 13°F in summer by late-century, while in climate over the course of this century, with lower emissions would cause roughly half this substantial impacts on vital aspects of the warming. state’s economy and character. If the rate of emissions is lowered, however, projections Precipitation and winter snow. The Northeast show that many of the changes will be far less region is projected to see an increase in winter dramatic. Emissions choices we make today—in precipitation on the order of 20 to 30 percent. Maine, the Northeast, and worldwide—will Slightly greater increases are projected under help determine the climate our children and the higher-emissions scenario, which would grandchildren inherit, and shape the conse- also feature less winter precipitation falling as quences for their economy, environment, and snow and more as rain. quality of life. Snow is nearly synonymous with winter in The research summarized here describes Maine and an integral part of many favorite win- how climate change may affect Maine and ter activities and traditions. If higher emissions other Northeast states under Maine two different emissions sce- 1961–1990 Migrating State narios. The higher-emissions 2010–2039 Climate scenario assumes continued heavy reliance on fossil fuels, 2010–2039 Changes in average sum- mer heat index—a measure causing heat-trapping emis- of how hot it actually feels, sions to rise rapidly over the 2040–2069 2040–2069 2070–2090 given temperature and course of the century. The lower- humidity—could strongly 2070–2090 emissions scenario assumes a affect Mainers’ quality of shift away from fossil fuels in life in the future. Red arrows favor of clean energy technolo- track what summers could gies, causing emissions to de- feel like over the course cline by mid-century. of the century under the The research also explores higher-emissions scenario; actions that individual house- yellow arrows track what holds, businesses, and govern- summers in the state could feel like under the lower- ments in the Northeast can Higher-Emissions Scenario emissions scenario. take today to reduce emissions Lower-Emissions Scenario to levels consistent with stay- ing below the lower-emissions scenario, and to adapt to the Photos: (from top) iStockphoto.com/Andy Thorington; Maine Department of Inland Fisheries and Wildlife; iStockphoto.com/Greg Nicholas; Captains of Industry; iStockphoto.com/Ben Thomas 2 CONF R O N T I N G C LI M AT E C HANGE IN THE U.S. N O R THEA S T • M AINE prevail, much of Maine—historically snow-covered for most of the winter— would see its snow season shrink by roughly half by late-century. Under the lower-emissions scenario, however, the state is expected to retain a substantial snow season—between two and four weeks of snow cover per winter month. Heavy, damaging rainfall events have already increased measurably across the Northeast in recent decades. Intense spring rains struck the region in both 2006 and 2007, for example, caus- ing widespread flooding. The frequen- cy and severity of heavy rainfall events is expected to rise further under either emissions scenario. Drought and stream flow. In this his- torically water-rich state, rising summer temperatures coupled with little change Bukaty AP Photo/Robert F. in summer rainfall are projected to in- A decline in spruce/fir forests would greatly exacerbate existing stresses on Maine’s crease the frequency of short-term economically important pulp and paper industry. (one- to three-month) droughts and de- crease summer stream flow, particular- therefore be conservative. However, sions scenarios, with the steepest losses ly if higher emissions prevail. By late- even under these projections, Maine’s under the higher-emissions scenario. century, for example, short-term droughts coast faces substantial increases in the Losses in spruce/fir forests will even- are projected to occur annually under extent and frequency of coastal flood- tually affect the animal species de- the higher-emissions scenario (com- ing, erosion, and property damage. pendent on them, such as the Canada pared with once every two to three lynx, snowshoe hare, and Bicknell’s years, on average, historically), while ImPACTS ON FORESTS thrush. Under the lower-emissions summertime conditions of low stream Forests cover 90 percent of Maine, pro- scenario, patches of the high-elevation flow (detrimental to native fish such as viding timber and firewood, plant and spruce/fir habitat required by the Bick- the Atlantic salmon) are projected to last wildlife habitat, and terrain for hiking, nell’s thrush could persist in the moun- an additional month, increasing stress snowmobiling, snowshoeing, fishing, tains of Maine, but under the higher- on both natural and managed ecosys- and birding. In addition, the forestry in- emissions scenario this bird’s distinctive tems. By contrast, little change in either dustry provides the state with more song could eventually be muted across drought or stream flow is expected un- than 19,000 jobs. the entire region as its suitable habitat der the lower-emissions scenario. As temperatures climb, the charac- gradually disappears. ter of Maine’s forests is expected to Warm winters interfere with tradi- Sea-level rise. Global warming affects change—particularly its spruce/fir for- tional timber harvesting practices in sea levels by causing ocean water to ex- ests, which are vital to the state’s nearly the region, which rely on frozen soil pand as it warms, and by melting land- $1.4 billion pulp and paper industry conditions to minimize damage caused based ice. Under the higher-emissions and treasured for their scenic and rec- by heavy equipment. With projected scenario, global sea level is projected to reational value. Spruce and fir species winter warming, the trend toward an rise between 10 inches and two feet by provide 50 percent of all sawlogs (used earlier or intermittent “mud season” is the end of the century (7 to 14 inches for lumber) and 20 percent of all pulp- expected to continue. under the lower-emissions scenario). wood (used for paper production) har- Long-lived trees may persist for These projections do not account for vested in Maine. some time even as the climate becomes the recent observed melting of the Climate conditions suitable for unsuitable for them; however, they may world’s major ice sheets—nor the poten- these forests are expected to decline in also become more vulnerable to com- tial for accelerated melting—and may Maine by late-century under both emis- petition from better-suited species and 3 CONF R O N T I N G C LI M AT E C HANGE IN THE U.S. N O R THEA S T • M AINE other stresses such as pests and dis- expected to shorten the average ski MARINE ImPACTS ease. Maine’s hemlock trees (which season, increase snowmaking require- A regional icon, Maine’s coastal fish- shade streams, providing cool condi- ments, and drive up operating costs ing villages contribute $393 million to tions required by native brook trout in an industry that has already con- the state economy each year. Com- and other fish) face both shrinking suit- tracted in recent years. Under the mercial fish and shellfish, including able habitat and the northward march higher-emissions scenario, western cod and lobster, have water-tempera- of the hemlock woolly adelgid, an inva- Maine is projected to be the only area ture thresholds that define the condi- sive insect that has already destroyed in the entire Northeast able to support tions required for their survival, growth, hemlock stands from Georgia to Con- viable ski operations by late-century. and reproduction. By increasing the necticut. With warmer winters project- However, in order to stay open, resorts region’s water temperatures, global ed under the higher-emissions scenario, in this area would require substantial warming is expected to bring more the adelgid is poised to infest hemlocks increases in snowmaking capacity and, changes to a sector that has already as far north as the Canadian border by therefore, operating costs. been transformed over the past several late-century, but would be prevented decades. from spreading into northern Maine Lake ice. Ice fishing and pond hockey this century under the lower-emissions are winter favorites in Maine. However, Lobster. In 2005 Mainers landed 70 mil- scenario. global warming will render lake ice lion pounds of lobster—more than half cover increasingly thin and shorten its of the annual U.S. catch. As the Gulf ImPACTS ON WINTER duration; ice cover duration on Sebago of Maine warms this century, deeper REcrEATION Lake has already declined by two weeks waters and coastal areas of Downeast The Pine Tree State has a long-estab- over the past several decades. Com- Maine may become increasingly suit- lished reputation as a winter getaway.