Hot days, warm nights. Heavy rains, no snow. A greater risk of wildfires and hurricanes, droughts and floods.
Released this week, the 236-page North Carolina Climate Science Report paints a dim picture of the new normal that will likely unfold through the century’s end. “Even under a scenario where greenhouse gas emissions peak around 2050 and decline thereafter, North Carolina will experience substantial changes in climate,” the report reads.
Carbon dioxide is emitted when power plants burn coal and when forests are cut. Methane is released by livestock, flooded rice paddies and, the report says, “to a largely unknown extent, inadvertently in the production of natural gas,” such as the Atlantic Coast Pipeline and MVP Southgate project that have been proposed for North Carolina.
Nitrous oxide is released by industry, agricultural activities, the burning of fossil fuels and solid waste, and wastewater treatment plants.
Even if every greenhouse gas — methane, carbon dioxide, nitrous oxide — stabilized or were eliminated today, the climate system needs time to fully respond to the change. It’s not an instantaneous. “It is virtually certain that the climate will continue to warm, and that changes in the system such as sea level rise, will continue.”
The document is a prelude to the NC Risk Assessment and Resilience Plan, due out this month from the state Department of Environmental Quality. It lays out, in scientific but stark terms, the likelihood of various climate change impacts on the state, as well as its main regions: the Coastal Plain, Piedmont and Mountains.
Here are several takeaways:
You won’t need a sweater …
By 2050, it’s very likely that temperatures “will increase substantially in all seasons,” by 2 to 4 degrees under a lower greenhouse gas emissions scenario, and 2 to 5 degrees if the emissions are higher.
The number of very warm nights, when temperatures don’t dip below 75, or below 70 in the mountains, will account for some of the uptick. Since 2005, the number of very warm nights has increased, with 2010 setting a record with a statewide average of 14. In fact, from 2008 to 2017, the number of very warm nights was higher than during any other consecutive 10-year period, according to the report.
In the Coastal Plain each year from 2015 to 2018 has
been one of the eight warmest on record. The same time frame has been the warmest four-year period on record for the Piedmont.
The length of the growing season is already 12 days longer than average; expect it to increase, as well as the duration of the freeze-free season.
With more water vapor in the atmosphere, it will “very likely” be more humid, amping up the heat index.
Why it matters: Excessive heat and humidity presents public health risks, not only for the elderly and those with underlying health issues, but also outdoor workers: farmhands, roofers, road construction crews, firefighters and landscapers. Without adequate nighttime cooling, the human body never gets a chance to recover from sultry daytime heat.
Agriculture also suffers. For example, some fruit trees need “chill hours” to bloom and produce. Even tomatoes, which thrive in hot, humid weather, won’t pollinate if the temperature doesn’t dip below 75 degrees.
Farmers will need to grow alternative crops, those that are better-suited for more tropical climes.
… or skis or a sled
If you’re a skier, we have some bad news. The amount of snowfall and the number of heavy snowstorms will likely decrease because of higher winter temps. Only the highest elevations — above 5,000 feet will get snow, and some mountain areas will be snowless. Even human-made snow will be unpredictable as conditions won’t be favorable to fire up the snow machine.
Snow will be rare in the Piedmont and Coastal Plain.
Why it matters: Forests in the mountains have adapted to cool temperatures; increasing temperatures, the report says, put “the viability of the high-elevation ecosystems at risk.” Mountain ski resorts at lower elevations will close, causing economic hardships. Snow days will be a strange phenomenon your kids will tell their grandkids about — similar to when GenXers and Boomers try to explain rotary phones to GenZ.
Flood plains could be uninhabitable
Because of Hurricanes Matthew and Florence, and Tropical Storm Michael, North Carolina recorded its highest number of extreme precipitation events from 2015 to 2018. That said, heavy rain and its attendant flooding will become even more common.
Along the northeastern coast of North Carolina sea levels have risen 1.8 inches per decade, in part because the land is also sinking there, while the levels have increased by 0.9 inches in Wilmington.
Dunes protect ocean front property from storm surge (as long as the dunes remain intact), but, the report notes, the sounds — like the Pamlico and Albemarle — “have no similar protection and inundation occurs as soon as the water level exceeds the low-lying adjacent topography.”
Those days when the air feels juicy? That’s a result of higher water vapor, which will very likely increase the frequency and intensity of heavy rainstorms, storm surge and flooding, including those associated with hurricanes. The 100-year storms — currently defined as having a 1% chance of occurring in any given year — will become more common. As will 500-year events, those with a 0.2% chance.
The mountains have been whipsawed by the weather. After devastating wildfires in 2016, the western mountains, in 2018, received a record 134.94 inches of precipitation at the Mount Mitchell weather station, a new state record for a single North Carolina station in a year.
Why it matters: More frequent flooding will occur not only on the coast, but also farther inland, which occurred during Florence. Flood maps will need updated to better illustrate the most vulnerable areas, potentially requiring people to move to higher ground. This is no small feat, not just logistically, but socially. The social fabric that holds communities together —a sense of identity, history and culture — they are all frayed when people are displaced.
If not rain, then fire
Depending on whether a community lies within a “rain shadow,” and receives less precipitation, or is on the “windward” side and gets more, can determine the drought and wildfire threat.
Over the remainder of the century, severe droughts are more likely not only in the mountains, but statewide because higher temperatures lead to increased soil and plant evaporation. And when the forest floor — the understory — dries out, that ups the wildfire risk.
Why it matters: The North Carolina mountains have some of the wettest and driest locations in the Southeast and the most diverse forests in North America. In 2016, wildfires burned for weeks, decimating 59,000-plus acres and forcing at least 1,000 people to evacuate. An increased number of droughts and wildfires could alter ecosystems and force residents to move, similar to those experiencing extreme flooding. Wildfires also emit immense amounts of air pollution, which can drift far from the source.
Where people meet the wild
The Wildland-Urban Interface is another name for the friction point where cities, towns, suburbs or exurbs meet undeveloped land. North Carolina has more acres at this interface than any other state in the country, according to the report, and that acreage increases every year. In North Carolina between 1990 and 2010, the acreage increased by more than 28%; there was nearly a 62% increase in the number of houses in Wildland-Urban Interface zones over the same period.
Why it matters: The increase in developed land near wild areas creates public safety challenges, particularly when dealing with wildfires. The 2018 California wildfires were destructive not only because of the number of acres burned, but because so many homes were in the way.
In addition, prescribed burns, which forest managers often use to mitigate the intensity of wildfires, are more difficult to conduct when homes are nearby.
The number of very warm nights, defined as a minimum temperature of 75 degrees in the Coastal Plain and Piedmont, and 70 degrees in the mountains, is expected to increase over the remainder of the century. Over the last 20 years, there has been an upward trend of warmer nights in all major regions of the state. Inadequate nighttime cooling can harm public health and agriculture. (Charts: NC Climate Science Report)