Dear Sara,

How will climate change affect public health in my home state of North Carolina in the next 20 or 30 years? – Katie B. in Virginia

This question is personal for me, because North Carolina is where I grew up and remains my home. But my reply is relevant to everyone in the U.S., not just to residents of the Tar Heel state – so listen up, y’all.

One recent federal report warns that if we take no action, climate change could cause thousands of premature deaths each year in the U.S. by the end of the century.

One of the biggest threats is the heat.

Story time: I grew up in the 1990s in Durham, North Carolina, where summer days were synonymous with sticky heat. To keep cool, my brothers and I spent almost every afternoon swimming at our community pool. But at dusk, the temperature would fall. It was often comfortable enough outdoors that we could venture into our backyard, where we captured fireflies in jars and played fierce games of flashlight tag.

Contrast that to life in central North Carolina today. Summer days remain hot, but when the sun sets, the temperatures don’t fall as swiftly. The loss of this nighttime break makes the heat feel relentless.

This isn’t a case of nostalgia making my memory fuzzy. As this chart from the recently released Fourth National Climate Assessment shows, the number of unusually warm nights – when the temperature never falls below 75°F – has shot up in the Southeast.

Unlike in most of the world, daytime highs in the Southeast haven’t warmed much since 1900. But scientists expect both days and nights to get hotter in the future — across the Southeast and elsewhere around the world — exposing more people to dangerous temperatures.

How heat harms our health

Extreme heat isn’t just uncomfortable. It’s bad for our health, in some cases leading to medical emergencies such as heat stroke.

Heat waves also put stress on our bodies. And when high temperatures linger overnight, our bodies don’t get a chance to cool off and recover, adding to the strain.

The danger is particularly acute for those with certain chronic health problems. On hot days, paramedics and hospital workers tend to see an increase in the number of people suffering from cardiovascular and respiratory complications, renal failure, preterm birth, and other conditions.

Dr. Mark Link, a cardiologist at UT Southwestern Medical Center in Dallas, put the problem in stark terms: “When you have heat waves,” he said, “there’s a spike in sudden cardiac death that is likely directly related.”

So if we do nothing about climate change, how bad could things get? One study calculated that by the late 2050s, heat waves across the eastern U.S. could cause roughly 3,600 deaths every year – 19 times the number estimated to have died from heat waves in the early 2000s. (By contrast, if we substantially reduce emissions of heat-trapping gases, there would be about 1,400 annual heat-related deaths, the researchers calculated.)

I haven’t even mentioned the plethora of other ways that climate change could make us sick. In addition to an increasing number of heat waves, we can expect to see longer allergy seasons, an increase in air pollution, more life-threatening weather disasters, an increased risk of vector-borne illnesses, and additional strains to our mental health.

It doesn’t have to be this way

The irony is that addressing climate change today wouldn’t just reduce the risk of health problems a few decades from now. Many of the steps to tackling the problem would confer immediate public health benefits.

1. Phasing out coal-burning power plants and replacing them with cleaner energy sources

Power plants that burn fossil fuels contribute to climate change by emitting heat-trapping gases. They also release other air pollution — such as sulfur dioxide, mercury, and fine particulate matter — that contribute to disease. As a result, shuttering the plants can lead to near-term health improvements.

For example, after eight coal- and oil-fired plants in closed in California, researchers discovered a decreased rate in the number of premature babies born near the plants. Another study found that as wind and solar energy displaced fossil fuels between 2007 and 2015, the resulting reduction in air pollution prevented thousands of premature deaths in the U.S.

Importantly, decisions about whether to close power plants are often made at the local level, not by the federal government. The Sierra Club has been working this angle for years in its long-running quest to end U.S. reliance on coal.

2. Driving less, walking and biking more

When an urban community has more bike lanes and better sidewalks, it’s easier to nudge people out of their cars and get them walking and biking. Carefully planned developments that place homes, businesses, parks, schools, and transportation hubs close to one other also encourage people to leave their cars behind.

When people drive less, they reduce their contributions to climate change. Walking and biking, of course, also offer the health benefits of exercise. One study from the Netherlands, where biking is common, found that people who regularly bike live an average of six months longer than non-cyclists.

As with power plants, most decisions about bike lanes, sidewalks, and new developments are made at the local level. Local civic engagement: underrated, actually crucial!

3. Planting trees

Trees soak up and store carbon dioxide, slowing the pace of climate change. They also provide shade that cools the local area, reducing the impacts of heat waves, and they absorb air pollution. One study of the effects of trees on human health in the U.S. calculated that in 2010, the air-filtering benefits of trees was worth $6.8 billion. Cities such as Louisville, Kentucky, San Fernando, California, and New York City are planting trees as part of their efforts to respond to climate change. So if you’re looking for a way to improve your community’s health and slow the heating of the planet, your opportunity might be as close as your front yard.

In a future column, I’ll offer a list of steps that individuals can take to protect their health as the climate changes. What should be on the list? Send your suggestions by tweet to @sarapeach or by e-mail to sara@yaleclimateconnections.org.