Pa. Climate May Look Like North Carolina’s in 50 Years

Anne Harnish
Lancaster Farming Staff

Climate change in Pennsylvania will impact dairy farmers and most other types of agricultural producers, say several reports released this fall on climate change. Changes in the Pennsylvania climate are expected to result in higher soil temperatures, more rain, higher carbon dioxide levels and increasing volatility in weather patterns.

According to the October report on Pennsylvania’s potential climate shifts by the Union of Concerned Scientists (UCS), the dairy industry will be effected by a variety of factors. Higher potential temperatures will add summer heat stress to livestock and result in lower milk production and lower birth rates in dairies.

The UCS report on the impacts of climate change in Pennsylvania was built on earlier collaborative research by the Northeast Climate Impacts Assessment (NECIA) released in 2006 and 2007. Many of its findings on Pennsylvania corresponded to those in an assessment published this fall by the University of Maryland’s Center for Integrative Environmental Research (CIER) report addressing the economic impacts on Pennsylvania of climate change.

As some Pennsylvania farmers are finding, there can be benefits to unusually warm and wet seasons possibly brought about by climate change factors. But there are negatives to warmer, wetter seasons too.

The CIER reported that “although greater concentrations of carbon dioxide in the atmosphere may contribute to higher growth productivities in forest and agricultural species, the benefits are projected to be temporary and will likely be offset by the projected spread of harmful pests and diseases.”

The UCS report stated that if rainfall becomes more unpredictable as climate changes occur, typically rain-fed crops in Pennsylvania may end up needing irrigation if the summer gets too hot.

While Pennsylvania soybean productivity is expected to rise under warming conditions, the same conditions will likely interfere with the corn pollination cycle in both sweet corn and field corn, said the CIER report on climate change. More intense summer heat waves, with “temperatures above 90 degrees (during the two-week pollination period) reduce the viability of the pollen, resulting in poor ear fill, reduced yield and lower quality.” And sweet corn may become more affected by “corn earworms and diseases like Stewart’s wilt.”

Under warming climate conditions, fruit crops such as apples won’t have the necessary cold winter periods for optimal production and neither will Concord grapes, said the UCS report. New pests may be introduced from warmer climes that won’t be killed off by long periods of cold. Variability in weather with extreme floods or storms can wreak unexpected havoc on fruits and other crops.

According to Penn State’s Jim Shortle, professor of agricultural and environmental economics, the most important thing is that farmers be adaptable to climate changes. Shortle has been researching and writing about climate change in the Mid-Atlantic region for more than eight years. He is less interested in mapping whether climate change is happening, or by how much it’s happening, than in determining how regions can adjust to changes.

Shortle has confidence in the ability of farmers to make changes as necessary, saying, “Farmers have always looked at what makes farming profitable.” He believes now is the time for state policymakers and universities to learn what to do to facilitate agricultural adaptation as climate changes increase.

Overall, most climate change experts predict the entire country will have increasingly warming temperatures. Shortle said in 50 years to expect that Pennsylvania will have a climate like North Carolina. He said North Carolina, along with the Southern states, will become drier and hotter, with reduced rainfall and higher temperatures. He noted that “agriculture looks different in North Carolina. There’s little dairy there, for example, partly because of the heat.”

In 100 years, Pennsylvania is forecasted to have a 6.3-degree Fahrenheit increase and a 7-percent increase in precipitation, according to the CIER report.

One study in the CIER report showed that above 77 degrees, dairy cows produce up to 22 percent less milk. With high humidity, heat stress can occur at even lower temperatures. Cooling and misting systems for cows may become a necessity if there are more and more very hot days, said the report.

The CIER publication also showed how difficult it is to plan for climactic changes: “While increased carbon dioxide (may) increase photosynthesis and forest and crop yields ... this projection is critical on the availability of timely precipitation, lack of disease-causing pests, and sufficient soil moisture, all of which are questionable under climate change scenarios.”

The complexity of climate change is enormous because nobody can know what is going to happen, said Shortle. “Things in the future are always going to be different, regardless of climate change,” he said, “and we don’t really know exactly what climate change will mean.” He believes that there are more important driving forces on agriculture in the Mid-Atlantic region than climate change. For example, the worldwide economic crisis is now a major player.

Adding to the complexity, supply and demand of agricultural products will change from state to state as climate change incurs losses or increases in agricultural yields for each state and around the world.

Pennsylvania farms, both big and small, will feel the effects of climate change. “Although farmers have often proven adaptable to changing weather patterns and market demands, they face greater uncertainty, risk and expense as the pace and scope of climate change increase,” reads the UCS report.

“Climate change will change the character not only of farmed landscapes, but also of Pennsylvania’s gardens, forests and other natural areas as the climate grows less suitable for many common flowers, shrubs and trees,” reads the UCS report. Pennsylvania’s forests may change quickly — from one generation to the next: “Climate conditions suitable for prized hardwood tree species such as black cherry, sugar maple, and American beech are projected to decline or even vanish from the state.”

In some cases, changing the types of apples or grapes grown in Pennsylvania will be necessary. The UCS notes that Macintosh and Granny Smith apples, which require about one thousand hours of winter chill may need to be replaced by “other fruits, or to apple varieties more tolerant of warmer winters.” Concord grapes may go by the wayside, becoming a “native grape in a non-native climate.”

According to the UCS report, Pennsylvania ranks third-highest in emissions release from fossil fuels, and emits one percent of the world’s total greenhouse gases, the major contributor to climate change. Sources of greenhouse gases (which include carbon dioxide, methane, nitrous oxide and chlorofluorocarbons) include fossil fuel combustion, industrial processes and agriculture, said CIER.

The report points out that “steep increases in atmospheric greenhouse gas concentrations have occurred (only) since the industrial revolution.”

Consequently, the UCS said, although climate change may have already started taking effect in Pennsylvania, the degree of those climate changes in the future is dependent on the will of its, and the world’s, people. “But the magnitude of warming that occurs during this century — and the extent to which Pennsylvanians will need to adapt — depends largely on energy and land-use choices made within the next few years in the state, the nation and the world,” stated the UCS report.

The report goes on to add that there are two “emissions scenarios”: one in which societies “allow emissions to continue growing rapidly,” and one in which “societies choose to rely less on fossil fuels and instead adopt more resource-efficient technologies.” According to the UCS, Pennsylvania has made some efforts by looking at renewable energy technologies like wind power and investing in energy efficiency, but could do much more to reduce climate change with proven strategies and available policies.

For more information or the complete reports, go to www.northeastclimateimpacts.org and www.cier.umd.edu/climateadaptation.