The sun is beating down so hard you swear you could fry bologna on the sidewalk; the air conditioning in your car is proving a weak opponent for humidity that you believe would rival a South American rainforest -- Charlotte's seen some hot days recently. Then there are the air quality warnings, code reds and oranges telling you the urge to stay inside isn't innate laziness. Surely, you think, this heat hasn't been normal.
Is this just summer in the South? Or could it be, Bush administration equivocations aside, that global warming is affecting Charlotte?
Unfortunately, climate change just isn't that easy to pin down. On a global scale, sure, most scientists do agree that greenhouses gases are causing temperatures to gradually increase in most regions, polar ice caps to melt, and sea levels to rise. But there's nothing in the weather report you can directly link to global warming, said Ryan Boyles, associate state climatologist for the State Climate Office of North Carolina.
"Climate change occurs over hundreds of years, and we only have 100 years of good data," Boyles said. "It's difficult to go in and look at any single event and talk about its direct relation to climate change."
Even predicting what could happen is guesswork.
The US Environmental Protection Agency estimates the average temperature in Chapel Hill increased 1.2 degrees Fahrenheit during the last century. Precipitation increased by up to 5 percent in many parts of the state during that same time, according to a 1998 EPA report on what global warming might mean for North Carolina.
That's just the beginning. Temperatures in North Carolina could increase by 3 degrees F. by 2100, and precipitation could increase by 15 percent, according to projections cited by the EPA. "The frequency of extreme hot days in summer would increase because of the general warming trend," the report states. "It's not clear how the severity of storms such as hurricanes might be affected, although an increase in the frequency and intensity of summer thunderstorms is possible."
Doesn't sound like much, does it? A degree here, a degree there. But even one degree can have serious effects.
That's one reason why Sen. Charlie Albertson, D-Duplin County, sponsored a bill to create a state global warming committee. The 32-member panel would bring environmentalists, business representatives and others together to study if it exists and what the state can do about it. Their recommendations would be due to the General Assembly before the 2007 legislative session. Versions have been passed by the state Senate and House of Representatives, and now a committee is working out the differences between bills. "I've always considered myself an environmentalist," Albertson said.
According to the state climate office, thunderstorms usually constitute the greatest economic loss from severe weather, costing more than $5 million a year. By one EPA-cited estimation, an extra three degrees Fahrenheit in Greensboro (Charlotte wasn't mentioned) could increase heat-related deaths by nearly 70 percent, though that could change if air-conditioning use increases. If conditions grow hotter and wetter, the number of mosquito-borne diseases such as encephalitis and malaria could increase.
If demand for water grows as temperatures rise, pollutants could become more concentrated. That could damage rivers such as the Catawba River, which supplies water for Charlotte and also receives discharge from many industries and towns.
"There's a whole range of things that could happen depending on how fast things warm as well as the sort of adaptations that humans have and how vulnerable we are," Boyles said.
Even those predictions aren't as reliable as global estimations. Scientists haven't yet developed models that reliably project what effects global warming could have on a local, or even regional, scale, Boyles said.
The effects of global warming may not be something people will notice during the next 50 years, Boyles said. But it's still something that should concern North Carolina residents. Greenhouse gases don't disappear quickly. "If we don't take action now, by the time all the science catches up, and we can give the type of precise forecast that we'd like to be able to make, it may be too late for us to make a quick impact," he said.