MISSISSIPPI: AVERAGE SUMMER TEMPERATURE
Source: American Climate Prospectus
100 95
89 92 110
86 83 80 77 74 70 50
Average Summer Temperature (°F)
2040–2059
2020–2039 2080-2099
Temperature increases have real impacts on Americans’
lives. By 2020-2039, extreme heat driven by climate change will likely claim as many as 260 additional lives each year in Mississippi. Annual additional heat- related deaths are likely to climb to 570 by 2040-2059—
exceeding the number of auto fatalities that Mississippi suffered in 2013.87
LABOR PRODUCTIVITY
Higher temperatures, spurred by climate change, are likely to drive down labor productivity and overall quality of life in Mississippi. Extreme heat stress can induce heat
exhaustion or heat stroke and can significantly reduce a person’s ability to carry out daily tasks. By mid-century, heat-related labor productivity declines across all sec- tors in Mississippi will likely cost the state economy up to
$784 million each year, with a 1-in-20 chance of costing more than $1.3 billion a year.
Workers in high-risk sectors such as agriculture, con- struction, utilities, and manufacturing are among the most vulnerable to higher outdoor temperatures and thus declining productivity. In 2011, one in three Missis- sippi employees worked in one of these high-risk sectors.
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MISSISSIPPI
Mississippi has had recent gains in labor productivity,88 but these are at risk as a result of climate change. The state is amongst the top five states in the country likely to have the steepest high-risk labor productivity penalties from warmer temperatures, with up to a 0.8% penalty by 2020- 2039, and up to a 1.6% penalty in the following 20 years.
ENERGY
As temperatures rise, Mississippi citizens and businesses are expected to require more air conditioning, which will lead to higher overall electricity demand. At the same time, power plants and transmission lines are known to become less efficient at very high temperatures. This combination of factors will likely require construction of additional power generation capacity to meet higher peak demand, which in turn will lead to higher electricity rates to cover the cost of new construction and transmission.
By 2020-2039, rising electricity demand related solely to climate change is likely to increase residential and commercial energy expenditures by up to 6%. Those increases will likely grow to up to 13% by 2040-2059.
Using future changes in temperature mapped against today’s U.S. energy market, this translates to higher statewide energy expenditures of $481 million each year by mid-century.
AGRICULTURE
Soybeans, corn, cotton and rice are Mississippi’s most valu- able crop commodities, having contributed about $2.2 bil- lion to production value in 2014. In fact, Mississippi ranks fifth in acreage use for cotton production nationwide.89 Mississippi faces significant climate risks to its commod- ity crop output if we stay on our current greenhouse gas emissions pathway. Our research focused on two specific climate impacts—changes in heat and precip- itation—and their interaction with four major com- modity crops in the Southeast: corn, soybeans, cotton and wheat. Crops are very sensitive to changes in their growing environment, particularly temperature.
Small increases in temperatures may benefit plants;
however, most crops have a specific threshold beyond which yields decline dramatically. Overall, impacts from climate-related temperature and precipitation changes are highly crop- and location-specific.
Though increased heat has the potential to depress yields, our analysis also takes into account the poten- tial yield benefits from increasing carbon dioxide in the atmosphere, which can stimulate crop growth and potentially reduce or even offset yield declines. Some crops, such as wheat, respond more favorably to this
Figure 20: Heat-Related Mortality (Additional Annual Deaths)
Source: American Climate Prospectus
Likely range
2020–2039 2040–2059 Auto Deaths
in 2013 1-in-20 chance
6
264 380
131 569
847
613 Extremely hot and humid temperatures will likely lead to more heat-related deaths in Mississippi, with hundreds more annual deaths possible by as soon as 2020-2039.
MISSISSIPPI
Figure 21: Change In Energy Costs
Likely range
2020–2039 2040–2059
1-in-20 chance -0.4%
6.0% 7.5%
3.9%
13.0% 15.1%
Source: American Climate Prospectus
Rising temperatures will increase statewide demand for electricity for air conditioning. Extreme heat also reduces power system efficiency, which increases costs for both producers and consumers.
“carbon fertilization” effect than others, such as corn.
On the other hand, our research does not take into account predicted climate-driven changes in water avail- ability or changes in the prevalence and distribution of pests, weeds and diseases, which can further influence yield outcomes.
With an annual value of $1.3 billion,90 soybeans are Mississippi’s most valuable crop. Absent significant agri- cultural adaptation, soybean yields will likely decrease by as much as 17% by 2020-2039 and as much as 42% in the following 20 years.
Other commodity crops will also suffer yield losses. Missis- sippi is one of the nation’s largest cotton producers, with nearly one million bales harvested in 2012.91 But, absent adaptation, that output will likely drop by as much as 7%
by 2020-2039 and as much as 20% by 2040-2059. The
state’s corn crop is likely to drop by as much as 27% by 2020-2039 and as much as 56% in the following 20 years.
On the other hand, Mississippi wheat benefits more from the carbon fertilization effect than it is harmed by temperatures increases. As a result, wheat yields are likely to increase over the course of the century as carbon dioxide concentrations continue to rise.
These yield declines can result in high economic costs.
By mid-century, the overall likely impacts of climate change on grain, oilseed and cotton yields to the state economy span gains ($109 million per year) to losses ($800 million per year, with a 1-in-20 chance of more than $1.0 billion in losses) due to the potential for economic gains from increases in yields. As corn, cotton and soybeans are the top three crops grown in the state, overall likely losses are larger than gains.
Figure 22: Change in Crop Yields
Likely range
2020–2039 2040–2059
1-in-20 chance 8.4%
-11.1%
-18.6%
9.5%
-30.4%
-41.5%
Source: American Climate Prospectus
Mississippi’s most valuable largest commodity crops face steep potential yield declines as a result of climate change.
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