US EPA

On This Page:

Đọc thêm

Overview

Agriculture is an important sector of the U.S. economy. The crops, livestock, and seafood produced in the United States contribute more than $300 billion to the economy each year.[1] When food-service and other agriculture-related industries are included, the agricultural and food sectors contribute more than $750 billion to the gross domestic product.[2] Agriculture and fisheries are highly dependent on the climate. Increases in temperature and carbon dioxide (CO2) can increase some crop yields in some places. But to realize these benefits, nutrient levels, soil moisture, water availability, and other conditions must also be met. Changes in the frequency and severity of droughts and floods could pose challenges for farmers and ranchers and threaten food safety.[3] Meanwhile, warmer water temperatures are likely to cause the habitat ranges of many fish and shellfish species to shift, which could disrupt ecosystems. Overall, climate change could make it more difficult to grow crops, raise animals, and catch fish in the same ways and same places as we have done in the past. The effects of climate change also need to be considered along with other evolving factors that affect agricultural production, such as changes in farming practices and technology.

Đọc thêm

Impacts on Crops

Despite technological improvements that increase corn yields, extreme weather events have caused significant yield reductions in some years. Source: USGCRP (2009) Click the image to view a larger version.Crops grown in the United States are critical for the food supply here and around the world. U.S. farms supply nearly 25% of all grains (such as wheat, corn, and rice) on the global market.[4] Changes in temperature, atmospheric carbon dioxide (CO2), and the frequency and intensity of extreme weather could have significant impacts on crop yields.For any particular crop, the effect of increased temperature will depend on the crop's optimal temperature for growth and reproduction.[1] In some areas, warming may benefit the types of crops that are typically planted there, or allow farmers to shift to crops that are currently grown in warmer areas. Conversely, if the higher temperature exceeds a crop's optimum temperature, yields will decline. Top of Page

Đọc thêm

Impacts on Livestock

Livestock locations in the continental United States. Source: USGCRP (2016) Click the image to view a larger version.Americans consume more than 36 million metric tons of meat and poultry annually.[4] Livestock and poultry account for over half of U.S. agricultural cash receipts, often over $100 billion per year.[5] Changes in climate could affect animals both directly and indirectly.Top of Page

Đọc thêm

Impacts on Fisheries

American fishermen catch or harvest five million metric tons of fish and shellfish each year.[7] U.S. fisheries contribute more than $1.55 billion to the economy annually (as of 2012).[8] Many fisheries already face multiple stresses, including overfishing an...

Đọc thêm

International Impacts

Climate change is very likely to affect food security at the global, regional, and local level. Climate change can disrupt food availability, reduce access to food, and affect food quality.[14] For example, projected increases in temperatures, changes in...

Đọc thêm

References

[1] USGCRP (2014). Hatfield, J., G. Takle, R. Grotjahn, P. Holden, R. C. Izaurralde, T. Mader, E. Marshall, and D. Liverman, 2014: Ch. 6: Agri­culture. Climate Change Impacts in the United States: The Third National Climate Assessment, J. M. Melillo, Te...

Đọc thêm

Bạn đã thích câu chuyện này ?

Hãy chia sẻ bằng cách nhấn vào nút bên trên

Truy cập trang web của chúng tôi và xem tất cả các bài viết khác!

studyenglish