{"id":13312,"date":"2020-06-11T09:23:53","date_gmt":"2020-06-11T13:23:53","guid":{"rendered":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/?page_id=13312"},"modified":"2024-08-15T13:08:16","modified_gmt":"2024-08-15T17:08:16","slug":"inside-the-greenhouse","status":"publish","type":"post","link":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/inside-the-greenhouse\/","title":{"rendered":"Inside the Greenhouse"},"content":{"rendered":"\n\n\n\n\n

We\u2019re moving rapidly into a different North Carolina than the one we used to know. Will 2020 surpass last year and bring even more record heat?<\/strong><\/p>\n\n\n\n

Those warm days last December when temperatures touched the 70s didn\u2019t just make you pull out the sandals for holiday break. They also helped 2019 secure the title of North Carolina\u2019s warmest year on record.<\/p>\n\n\n\n

Earlier this year, our colleagues in Asheville at NOAA\u2019s National Centers for Environmental Information confirmed 2019\u2019s record-breaking status. They calculated national, state-level, and local average temperatures and precipitation using quality-controlled weather station observations. These data date back to 1895.<\/p>\n\n\n\n

It\u2019s our best and most accurate measure of surface weather conditions using on-the-ground monitoring sites, which is a fancy way of saying good old-fashioned thermometers and rain gauges. This tried-and-true equipment tells us that 2019 consistently moved the mercury higher than any other year observed.<\/p>\n\n\n\n

To break down this record and what it means \u2014 and where we\u2019re headed in 2020 \u2014 here are the answers to some common questions about climate change in North Carolina.<\/p>\n\n\n\n

HOW DID IT HAPPEN?<\/h2>\n\n\n\n

In short, our temperatures were generally temperate, and our prevailing air masses were typically tropical. Just two months all year \u2014 March and November \u2014 had below-normal statewide average temperatures, while three others \u2014 May, September, and October \u2014 all ranked among the top-five warmest.<\/p>\n\n\n\n

That early-summer onset and early-fall persistence of heat and humidity were ultimately among the most memorable parts of the year, and they helped make it such a warm one.<\/p>\n\n\n\n

A stubborn subtropical high-pressure system made our weather so hot and humid during that time, but much earlier similar weather systems also had set up off our coast and given us a warm finish to the winter.<\/p>\n\n\n\n

The statewide average mean temperature of 61.22\u00b0F last year edged out the 61.08\u00b0F average from 1990, but crucially, it was 2.7 degrees warmer than the 1901 to 2000 average temperature of 58.5\u00b0F.<\/p>\n\n\n\n

And it wasn\u2019t just our mean temperatures. 2019 was also our record warmest year based on average minimum temperatures \u2014 each of those warmest years coming in the past five years \u2014 and 2019 also was our fifth-warmest year based on average maximum temperatures.<\/p>\n\n\n\n

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IS THERE A WARMING TREND IN NORTH CAROLINA?<\/h2>\n\n\n\n

In the past 30 years, North Carolina has recorded each of its five warmest years on record \u2014 along with 10 of its top 30 warmest years.<\/p>\n\n\n\n

Over that same time, we have recorded zero of our 30 coolest years on record. The last year that cold was 1988 \u2014 our 15th-coolest year \u2014 when Phil Collins was on top of the Billboard pop charts and the elder George Bush had just won the White House.<\/p>\n\n\n\n

\"A<\/a><\/figure>\n\n\n\n

The 80s also was a decade with several extreme cold events, including the state\u2019s infamous \u201cColdest Day\u201d in January of 1985, when many sites set their all-time record lows, and the Christmas blizzard in 1989 at the coast, which blew through with sub-zero temperatures following it.<\/p>\n\n\n\n

Similar atmospheric setups have brought some cold weather since then, but we haven\u2019t approached those record lows. In fact, record lows are getting harder to come by. In 2019, 881 daily maximum temperatures broke or tied records across North Carolina, which was almost four times the number of daily minimum temperatures that broke or tied records in the state.<\/p>\n\n\n\n

That\u2019s another way of showing that it\u2019s been more warm than cool recently, and it\u2019s one sign that North Carolina is experiencing the consequences of a warming planet. Essentially, the climate system is more sensitive to warming nighttime temps, and we see the dominant trend is in our nighttime lows \u2014 readings that have consistently pushed some of our recent warm years into the top 10.<\/p>\n\n\n\n

WHAT DO WE KNOW ABOUT 2020 SO FAR?<\/h2>\n\n\n\n

We began this year the same way we ended last year \u2014 with overall warm weather. January and February were each the 11th-warmest out of the past 126 years, and March was our fifth-warmest on record statewide.<\/p>\n\n\n\n

The same large-scale, high-pressure system that made for so many warm months in 2019 was also at play this winter and early spring. However, that pattern relaxed in April, which had near-normal temperatures on average.<\/p>\n\n\n\n

When comparing the first four months of the year only, 2020 ranks as the fourth-warmest on record \u2014 trailing 2017, the warmest year at the one-third mark, by a little less than a degree. Our average temperature so far this year is also a full 1.7\u00b0F warmer than at the same point last year.<\/p>\n\n\n\n

Of course, that\u2019s no guarantee that 2020 will top the list of our warmest years as well, especially with several months still to go. But we\u2019re off to a warm start, and many of the same trends we\u2019ve observed in recent years \u2014 including the warmth in our nighttime lows \u2014 are holding true so far this year.<\/p>\n\n\n\n

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WHAT WILL THIS MEAN FOR FUTURE YEARS?<\/strong><\/h2>\n\n\n\n

Even on a warming planet, North Carolina\u2019s climate isn\u2019t a staircase. There\u2019s no guarantee that going forward we will see day-to-day, month-to-month, and year-to-year variability in our weather, and not every year will be warmer than the ones before it.<\/p>\n\n\n\n

But if you\u2019re a gambler, we\u2019re stacking the deck with more warm daily temperature records than cool ones. And those warm days and nights add up to warm months, which make for warm years.<\/p>\n\n\n\n

There almost certainly will be more record-breakers, based on future global temperature projections. In North Carolina, the climate will warm anywhere from 4\u00b0F to 10\u00b0F by the end of the century. The addition of heat-trapping greenhouse gases to the atmosphere over a relatively short time means that warmer years are more likely than cooler ones, which is exactly what we\u2019ve already seen over the past three decades.<\/p>\n\n\n\n

Small changes in these annual averages mean big shifts in our extremes. Our hottest days and nights are getting hotter.<\/p>\n\n\n\n

Not every October will feel like August, as it did in 2019, but that\u2019s likely to become a more common occurrence, especially as the warmer climate creates more evaporation from the oceans, more condensation in the air, and, overall, a more tropical environment that could infiltrate our springs and falls.<\/p>\n\n\n\n

Likewise, locations like Raleigh \u2014 which is already having more intense and longer heatwaves, according to the National Climate Assessment \u2014 may see a transition to a warmer climate more similar to Savannah\u2019s than its historically moderate one.<\/p>\n\n\n\n

WHY DOES IT MATTER?<\/h2>\n\n\n\n

First and foremost, heat is a human health issue. According to the National Weather Service, it is the #1<\/strong> weather-related killer. And with more extreme temperatures, longer heatwaves, and general socioeconomic disparity, the risks only increase.<\/p>\n\n\n\n

More people will be exposed to lethal temperatures. Some of our most sensitive populations in North Carolina lack access to sufficient cooling or live in urban areas covered in asphalt without access to shade. We also have outdoor laborers on our farms and in construction, who face extreme heat during the day and little relief at night.<\/p>\n\n\n\n

Although milder winters and faster-emerging springs could extend the growing season and make our climate more hospitable to crops such as citrus fruits, more intense summer heat will also increase the stress on crops and make year-to-year yields more unpredictable.<\/p>\n\n\n\n

Stone fruits will lack the chilling hours, or cooler temperatures, required for their development. That\u2019s not speculation; it\u2019s a phenomenon that peach farmers in Georgia are already facing. Likewise, the things we grow in North Carolina are accustomed to a specific climate.<\/p>\n\n\n\n

In addition, with those longer growing seasons and extended warm periods, we could see the emergence of things we don\u2019t want: more weeds, pests, and invasive species. Warmer weather also provides a more hospitable climate for the bugs that carry vector-borne diseases.<\/p>\n\n\n\n

We\u2019re moving rapidly into a different North Carolina than the one we used to know. It is warmer, wetter, and generally more prone to extremes of intense daytime heat, hot nights, and heavy downpours.<\/p>\n\n\n\n

Yet, drought and wildfire are also part of North Carolina\u2019s climate, and our state remains susceptible to the same growing extreme we\u2019ve seen on the West Coast.<\/p>\n\n\n\n

Benchmarks like \u201cthe warmest year on record\u201d don\u2019t just make for coffee-shop small talk. They\u2019re evidence in the case pointing to a global phenomenon that already affects us here, in our own backyard.<\/p>\n\n\n\n

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What to Expect from Climate Change
Projections from the North Carolina Climate Science Report<\/em><\/strong><\/span><\/h2>\n\n\n\n

In March, the North Carolina Institute for Climate Studies released the North Carolina Climate Science Report, an independent assessment of observed and projected climate. The report provides crucial information about the past, present, and future of climate change.<\/p>\n\n\n\n

NC State University\u2019s Kenneth Kunkel assembled the team that wrote the report and the Climate Science Advisory Panel that provided scientific oversight. The panel included scientists with national and international reputations.<\/p>\n\n\n\n

The panel based its projections for climate change on what the report calls \u201cthe virtual certainty that greenhouse gas concentrations\u201d will continue to rise. As a result, the panel\u2019s overarching conclusion is that \u201clarge changes in North Carolina\u2019s climate, much larger than at any time in the state\u2019s history, are very likely by the end of this century.\u201d<\/p>\n\n\n\n

Key Conclusions<\/h2>\n\n\n\n

TEMPERATURE<\/strong><\/p>\n\n\n\n

The most recent 10 years represent the warmest 10-year period on record in North Carolina.<\/p>\n\n\n\n

It is very likely<\/strong> that North Carolina temperatures will increase substantially in all seasons. Annual average temperature increases relative to the recent climate for North Carolina are projected to be 2\u00b0F to 5\u00b0F by the middle of this century.<\/p>\n\n\n\n

It is very likely<\/strong> that the number of warm and very warm nights will increase.<\/p>\n\n\n\n

It is very likely<\/strong> that summer heat index values will increase because of increases in absolute humidity.<\/p>\n\n\n\n

It is likely<\/strong> that the number of hot and very hot days will increase.<\/p>\n\n\n\n

It is likely<\/strong> that the number of cold days (with daytime maximum temperatures below 32\u00b0F) will decrease.<\/p>\n\n\n\n

PRECIPITATION<\/strong><\/p>\n\n\n\n

There is no long-term trend in annual total precipitation averaged across the state. However, there is an upward trend<\/strong> in the number of heavy rainfall events (3 inches or more in a day), with 2015 to 2018 having seen the greatest number of events since 1900.<\/p>\n\n\n\n

It is likely<\/strong> that annual total precipitation for North Carolina will increase.<\/p>\n\n\n\n

It is very likely<\/strong> that extreme precipitation frequency and intensity in North Carolina will increase due to increases in atmospheric water vapor content.<\/p>\n\n\n\n

SEA LEVEL<\/strong><\/p>\n\n\n\n

Sea level along the northeastern coast of North Carolina has risen about twice as fast as along the southeastern coast, averaging 1.8 inches per decade since 1978 at Duck and 0.9 inches per decade since 1935 at Wilmington.<\/p>\n\n\n\n

It is virtually certain<\/strong> that sea level along the North Carolina coast will continue to rise due to expansion of ocean water from warming and melting of ice on land, such as the Greenland and Antarctic ice sheets. High-tide flooding is projected to become a nearly daily occurrence by 2100.<\/p>\n\n\n\n

HURRICANES<\/strong><\/p>\n\n\n\n

The intensity of the strongest hurricanes is likely<\/strong> to increase with warming, and this could result in stronger hurricanes impacting North Carolina. Confidence in this result is high for global hurricane changes but lower for North Carolina specifically.<\/p>\n\n\n\n

Heavy precipitation accompanying hurricanes that pass near or over North Carolina is very likely<\/strong> to increase, which would in turn increase the potential for freshwater flooding in the state.<\/p>\n\n\n\n

There is low confidence in predicting future changes in the number of landfalling hurricanes in North Carolina.<\/p>\n\n\n\n

STORMS<\/strong><\/p>\n\n\n\n

It is likely<\/strong> that the frequency of severe thunderstorms in North Carolina will increase.<\/p>\n\n\n\n

It is likely<\/strong> that total snowfall and the number of heavy snowstorms in North Carolina will decrease, but there is low confidence in predicting both future changes in the number of winter coastal storms and the number of ice storms in North Carolina.<\/p>\n\n\n\n

FLOODS, DROUGHTS, AND WILDFIRES<\/strong><\/p>\n\n\n\n

It is virtually certain<\/strong> that rising sea level and increasing intensity of coastal storms, especially hurricanes, will lead to an increase in storm surge flooding in coastal North Carolina.<\/p>\n\n\n\n

It is likely<\/strong> that increases in extreme precipitation will lead to increases in inland flooding in North Carolina.<\/p>\n\n\n\n

It is likely<\/strong> that future severe droughts in North Carolina will be more intense due to higher temperatures leading to increased evaporation. As a result, it is likely that the frequency of climate conditions conducive to wildfires in North Carolina will increase.<\/p>\n\n\n\n

URBAN GROWTH<\/strong><\/p>\n\n\n\n

It is likely<\/strong> that future urban growth will increase the magnitude of the urban heat island effect, with stronger warming in North Carolina urban centers.<\/p>\n\n\n\n

the full report<\/em><\/a><\/p>\n\n\n\n

The North Carolina Institute for Climate Studies<\/em><\/a><\/p>\n\n\n\n

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READ MORE<\/strong><\/p>\n\n\n\n

Coastwatch<\/em> on climate change<\/a><\/p>\n\n\n\n

The NC Climate Divisions Dataset<\/a><\/p>\n\n\n\n

\u201cThe Coldest Day Redefined Records\u201d<\/a><\/p>\n\n\n\n

\u201cA Coastal White Christmas: Revisiting the 1989 Winter Storm\u201d<\/a><\/p>\n\n\n\n

\u201cEmission Levels Determine Temperature Rises\u201d<\/a><\/p>\n\n\n\n

National Climate Assessment<\/em><\/a><\/p>\n\n\n\n

\u201cChill Hours for Peaches and Other Fruit Even Lower than Last Year\u201d<\/a><\/p>\n\n\n\n

Corey Davis is an applied climatologist at the North Carolina State Climate Office and an NC State graduate with a bachelor\u2019s degree in meteorology and a master\u2019s in atmospheric science. Born in the Triad and now based in the Triangle, Corey has spent his life observing North Carolina\u2019s weather \u2013 from hurricanes to humidity to those fickle snow and ice storms \u2013 and he now writes about it for the State Climate Office\u2019s Climate Blog: climate.ncsu.edu\/climateblog.<\/em><\/p>\n\n\n\n

Kathie Dello is the state climatologist of North Carolina and the director of the North Carolina State Climate Office at NC State University. She is originally from New York State and most recently spent a decade in Oregon, where she earned her Ph.D. in environmental science from Oregon State University. Kathie moved to North Carolina last year and loves all that it has to offer: good food, green space, mountains, and the beach.<\/em><\/p>\n\n\n\n

lead photo<\/em>: Climate change likely will create more frequent conditions for wildfires like the one in Whipping Creek, N.C. Courtesy of the U.S. Department of Agriculture.<\/span><\/p>\n\n\n