Agriculture and fisheries are closely linked to climate,
making them vulnerable to changes in temperature, CO2 levels,
and extreme weather. While increased temperature and CO2 can
enhance some crop yields, this depends on factors like nutrient
levels, soil moisture, and water availability. More frequent
droughts and floods could challenge food production and safety,
while warming waters may shift fish habitats, disrupting
ecosystems. Overall, climate change may complicate traditional
methods of farming, livestock raising, and fishing.
Crop responses to temperature changes depend on each
crop's optimal growth temperature. Warmer conditions might
benefit certain crops or enable the cultivation of new ones, but
yields decline if temperatures exceed a crop's threshold.
Increased CO2 can enhance plant growth under controlled
conditions but may be offset by water, nutrient, and temperature
constraints. Additionally, elevated CO2 reduces the protein and
nitrogen content in crops like soybeans and alfalfa, lowering their
quality and diminishing the forage value for livestock.
Extreme weather events, such as floods and droughts, can
harm crops and reduce yields. For example, high nighttime
temperatures in 2010 and 2012 lowered U.S. corn yields, while
premature budding caused $ 220 million in losses for Michigan
cherries in 2012. Rising summer temperatures may also dry soils,
complicating drought management. Increased irrigation could
help, but reduced water availability might limit its feasibility.
Climate change also favors weeds, pests, and fungi, which
thrive in warmer, wetter conditions with higher CO2 levels. This
could expose crops to new threats and increase farming costs.
U.S. farmers already spend over $ 11 billion annually on weed
control, and these challenges are likely to grow as weed and pest
ranges expand.
While rising CO2 stimulates plant growth, it also lowers
the nutritional value of major crops like wheat, rice, and
soybeans by reducing their protein and mineral content. This
poses a potential risk to human health. Additionally, increased
pest pressure may lead to higher pesticide use, further impacting
health and reducing pesticide effectiveness. Climate change,
therefore, presents multifaceted challenges to food production,
nutrition, and ecosystems.
Internet:<climatechange.chicago.gov> (adapted).