The Northeast region is an important contributor to our nation's supply of dairy products and food crops, including apples, grapes, potatoes, sweet corn, onions, cabbage, and maple syrup. Some of the potential effects of climate change are likely to be positive for agriculture in the Northeast. For example, warmer temperatures are likely to prolong the growing season, and the increased levels of carbon dioxide are likely to enhance plant growth and water use efficiency for many crops. However, the majority of New York's and New England's most competitive crops are cool-season crops. While it might seem that a successful response would be for farmers growing crops well suited to present climate conditions to switch to alternative warm-season crops, they would now have new competitors who might have advantages such as better soils and a longer growing season. Adaptability is thus very likely to be critical to the continued success of agriculture in the Northeast should projected climate changes occur.

As farmers in the Northeast adapt to a changing climate, economic resources and adjusted government policies are likely to be required. Four areas of uncertainty are likely to impact the future of agriculture in the Northeast: the amount of regional change in temperature and precipitation; the extent to which carbon dioxide fertilization affects various crops and their yields; the ability of farmers to adapt to changes; and the state of the global market. Each of these uncertainties is important. In addition, the continued loss of ‘family farms' and the conversion of agricultural lands to forests and to urban uses are likely to be significant concerns. The following sections discuss potential impacts on the region's agricultural economy and strategies that may be useful in addressing the potential impacts from climate changes.

Environmental Impacts

The quality of the soil in the Northeast has the potential to be improved by climate change. The soil could become more productive because it could store more organic matter and carbon. At present most US farmland has only half or less of the historical level of organic matter. Soil scientists have established that a 6-inch block of soil with 1 to 2% organic matter can hold only about one inch of rain before it runs out the bottom. With 4 to 5% organic matter, that same amount of soil can hold 4-6 times more rain before the water leaves the root zone, taking water-soluble nutrients with it. Increasing soil organic matter also reduces the risks of flooding and erosion and helps the soil retain moisture longer so plants have access to it during periods of dry weather. Additional soil organic matter would also lessen the need for and expense of irrigation, reduce ground water pollution, and reduce the amount of run-off, lessening the threat of stream pollution. It would also lower fertilizer costs because nutrients not lost to erosion and leaching need not be replaced.

The fertilization effect of higher levels of atmospheric carbon dioxide on agriculture in the Northeast is uncertain. Many crops will benefit from increased levels of atmospheric carbon dioxide. However, how much benefit depends on the plant type, the temperature, the availability of water (even though increased CO2 generally makes plants more efficient users of water), and available plant nutrients (not usually a problem because of the use of fertilizer). Further, some combinations of elevated carbon dioxide levels and temperature are more beneficial than others. If adequate water is available, increased carbon dioxide and temperatures often increase crop productivity. Increased carbon dioxide levels have also been shown to provide beans and cucumbers, for example, some protection from injury due to chilling temperatures. Increased carbon dioxide levels are also likely to increase production of soybeans and tree fruits. However, corn, an important regional crop, shows very little benefit from increased carbon dioxide levels at any temperature (it can benefit from other climate changes). Certain weeds are also likely to benefit from higher levels of carbon dioxide, thus necessitating increased application of herbicides, which may lead to other environmental impacts.

Many crops are likely to benefit from warmer temperatures and longer growing seasons, conditions that are likely to accompany increases in atmospheric carbon dioxide. However, an increase of several degrees actually could reduce photosynthesis (the process that plants use to absorb carbon dioxide from the atmosphere and convert it to sugars used for energy and growth) for crops growing near their optimum temperature. Such a response could shorten the growth period and reduce crop yield. The rate of plant development also can affect crop yield. Yields are reduced in grain-type plants when higher temperatures speed crops through their growth phases. In addition, brief high temperatures at critical stages in a plant's development can severely reduce the quality of some cool-season vegetables and fruit crops. Higher temperatures in the Northeast are also likely to allow the survival of pests that normally do not withstand cold winters. Increased pest populations would result in additional threats to crops and livestock and the heightened need for pesticides. Applying these pesticides has the potential of creating additional environmental concerns.

Farm animals are also directly affected by temperature. Impacts on dairy production in the Mid Atlantic region are not expected to be serious. However, the type of dairy cattle raised in New England and New York perform best in cool climates (40˚ to 75˚ F) and are sensitive to heat stress. Moreover, high relative humidity, which occurs frequently in the Northeast, aggravates the problems high temperatures cause. With relative humidity at 80 %, heat stress for certain dairy cattle can begin at temperatures as low as 73˚ F and become severe at 93˚ F. Under certain conditions farmers in some locations are already keeping their cows in climate controlled buildings; this could become the norm in more northerly locations as well.

If favorable cool-climate conditions shift north into what are now natural ecosystems, environmental impacts could arise in the event of conversion of forested land to agriculture including: increased risk of ground and surface water pollution, depletion of water resources, and loss of wildlife habitat. Such consequences could be offset or become a positive situation if existing farmlands revert to more natural states.

Societal Impacts

The social and political consequences of changes in the agriculture industry could well go beyond farmers to affect local economies and land use governance, and the supply and price of locally grown agricultural commodities at the supermarket. If climate changes cause the competitive position of some farmers in the northeast to be weakened, additional family-owned farms could be eliminated. The loss of family farms is already a regional and national concern, because it changes the social and cultural aspects of this rural lifestyle. However, there also will be winners within the farming community to the extent that economic use can be made of the warmer temperatures, longer growing seasons, and increased carbon dioxide concentrations.

Because about one fourth of the Mid Atlantic region's land area is agricultural, its presence defines many of the region's rural landscapes. Rural and urban populations from within and around the northeast enjoy and benefit from the agricultural vistas and consider them to be a valuable amenity. Residents and visitors who consider agricultural areas important to the region could feel disappointment should the decline in farming, due to climate change and other reasons, happen faster. Besides providing vistas, agricultural land is an important habitat for a variety of wildlife species (e.g., Canada geese, deer, wild turkey, etc.); significant changes in the extent of agriculture could thus alter the region's fauna.

Agriculture is also a contributor to negative environmental impacts (e.g., nutrient and pesticide runoff, and erosion). If livestock production, particularly in the Mid-Atlantic region, continues to be important, projected increases in heavy precipitation could cause high levels of run-off and nutrient leaching. Higher run-off levels into freshwater supplies and estuaries would be likely to affect water quality in the region and could increase the potential for waterborne diseases, such as cryptosporidiosis. On the other hand, changes in cultivation practices such as low-till/no-till would be likely to increase the organic content of the soil and thereby increase its ability to sequester carbon, hold water, resist drought, avoid erosion, and limit nutrient loss. Increasing the organic content of the soil would also reduce the need for additional fertilizers -- a win-win situation for farmers, other water users, and the environment.

Economic Impacts

The regional importance of agriculture is declining, reflecting national trends, but small family farms throughout New England and other parts of the northeast are still vital to the economy of rural areas. These farms fill an important niche by providing fresh, high quality, and affordable local produce. It is often not recognized that New York ranks within the top three states in the nation for producing apples, grapes, sweet corn, snap beans, cabbage, milk, and cottage cheese, and its agricultural contribution to the economy approaches $3 billion annually.

Even though about one-fourth of the land area is agricultural in southern portions of this area (e.g., MAR), the contribution to the economy is fairly small. Crops (including both sales and products consumed on the farm) are grown on only about one-fourth of the agricultural land in this region, but are important commodities and account for three-fourths of the Mid Atlantic Region's total value of agricultural production. Approximately, 65% of MAR agricultural sales are from livestock and livestock products.

Reliable crop models are not available for many of the northeast's high-value crops. However, model projections, despite their uncertainties, suggest a range of changes to crop yields that could help or harm this region's economic welfare.

• An EPA study suggests that the agricultural yields in New York and Connecticut could decrease by as much as 40 percent. (This estimate assumes farmer's continue to grow the same crops rather than implement any adaptation strategies or use more suitable crops.)
• The Mid-Atlantic regional assessment study found likely positive impacts to tobacco (but not to tobacco farmers because tobacco would grow even better in other places thus increasing the competition from producers outside the region), soybeans, tree fruits, and possibly corn yields.
• Findings of the US National Assessment Agriculture sector study found that corn is affected both positively and negatively depending on location and irrigation, but in general changes look positive for the Northeast; potatoes in this region are likely to suffer only small losses or slight increases; and soybean yields should increase.

While much of this looks positive, these crops are not the largest income producers for many of the farms in this region. There are also questions about whether these model results are relevant predictors for crop yields and the economic implications for other crops of importance to small, northeastern producers.

Another economic concern could be the direct and indirect costs in adapting to new practices dictated by climate change. These costs could be related to developing better-adapted crop strains or to switching crops entirely should that be required in some areas. The direct costs to farmers to take advantage of carbon dioxide fertilization could include:

• more use of fertilizer because increased growth increases the need for nutrients (and soils in the region are not uniformly of high quality);
• more use of pesticides because higher temperatures are likely to accompany higher carbon dioxide levels and pests are likely to do better with higher temperatures;
• more use of herbicides because many weeds are likely to grow better with higher carbon dioxide levels; and
• more need for water as temperatures increase (even though the enhanced CO2 concentration often helps plants use water more efficiently). Increased water use could require additional infrastructure for irrigation -- presently a very small amount of northeastern agriculture is irrigated.

Indirect consequences could include impacts on the quality of agricultural products themselves. There also could be positive impacts to agriculture elsewhere, resulting in increased competition from producers outside of the Northeast. For example, the quality of cool-weather crops might be reduced by the incidence of brief high-temperature events; these lower-quality crops would receive lower prices at market or merit a smaller share of the market. Another example results from the impact of heat stress on dairy cattle; heat stress can reduce milk production for up to 180 days after a high-temperature stress period. As noted above, the profitability of tobacco to this area's farmers could be reduced by an improvement of growing conditions elsewhere in the world, thus increasing the competition from outside producers.

While the overall impact on agriculture in the United States is likely to be positive, it is also likely that there will be locations with negative impacts due to high temperatures, increased pest pressures, lack of locally adapted varieties, or highly competitive markets for adapted crops. It is thus possible that some farms will benefit and that others will go out of business when their adaptation strategies are not effective. Of course, such consequences are possible even without climate change. Projected climate changes could cause more economically, politically, and socially stressful transitions for some northeastern farmers, even though the national and regional outlook is positive.

Strategies to Address Potential Impacts on Agriculture

Strategies to address potential climate change impacts on agriculture in the Northeast focus on minimizing the increased costs that could accompany the projected impacts. The following is not an exhaustive list, but identifies some possible strategies:

• Develop more accurate short (monthly) to medium (several seasons) climate forecasts and regionally appropriate crop models. The results could help farmers choose the most appropriate crop types for each growing region;
• Plant crops that are better adapted to the changing climatic conditions -- this option could involve the use of biotechnology and/or other genetic manipulation;
• Build controlled-environment facilities for vulnerable farm animals;
• Plan for additional infrastructure to support irrigation, if needed; and
• Examine economic and governmental policies that could aid in addressing potential impacts on agriculture; examples could include allowing more flexibility in financing, government policies and regulations, and expanding alternative employment options.