What can be done to protect communities from what some call a silent killer? One approach is to target roads. Asphalt and concrete absorb the sun’s energy and radiate it back as heat well into night, warming the air after the sun goes down. “So far, the data is telling us that those areas that are most plagued with asphalt and concrete, and a lack of vegetation, you know, are the places where it's hottest,” Na’taki Osborne Jelks, an environmental health scientist at Spelman College, said in an interview for “Weathering the Future.” In collaboration with Arizona State University, the city of Phoenix is recoating asphalt roads with a special sealant that reflects away more sunlight so that it can’t be absorbed and radiated as heat. One study projects that this approach could lower the average temperature of some cities by 2.5 degrees.

Replenishing lost vegetation is another solution because the loss of trees in cities makes them hotter. Direct sunlight can add up to 15 degrees F to what the human body experiences. Adding vegetation can both cool the air and provide shade.

Wildfires

As increasing temperatures have led to warmer, drier conditions in some areas, wildfires have escalated, becoming both more frequent and more intense in recent decades. The West and Southwest have experienced this acutely: Between 2012 and 2021, over 24% of forested land in California burned.

The Federal Emergency Management Agency describes a wildfire as “an unplanned, unwanted fire burning in a natural area, such as a forest, grassland, or prairie.” The cause can be anything from lightning to a stray cigarette to arson. Climate change has intensified wildfires in part because warmer temperatures can dry out trees, grasses, and shrubs, making them even more combustible. But this is compounded by the fact that long-standing policies of fire suppression in the West have led to a buildup of these wildfire fuels. 

Some Western states are addressing the issue by embracing Native American burning practices. Regular low-intensity fires can thin out the forests and eliminate the fuel that causes wildfires to burn out of control. And for thousands of years, some Native American groups in the West used fire to shape and protect the landscape. “Fire is not inherently bad. This landscape evolved with fire. The species on this landscape are fire dependent species. You can’t take fire out of this landscape,” Leaf Hillman, a tribal elder of the Karuk people of northern California, told NOVA. But starting in the 1800s, White settlers in the West wanted to prevent fires they thought would threaten their towns and the forests they saw as a source of income. They criminalized intentional burning and punished Native Americans who followed their traditional fire practices. Now, California forests are twice as dense as they were 200 years ago.

But as wildfires burn increasingly out of control, state and federal agencies are reconsidering their strategy of fire suppression. In California, the Karuk and other Native American groups are working to bring back their ancient practices. And the U.S. Forest Service is also adopting “prescribed burn” practices to manage forests with fire on a larger scale. Intentional burning allows people to select specific areas to burn and do so when conditions like humidity and wind are such that the risk of escape is lowest. The result? A methodical process that nurtures native species and helps keep wildfires contained.

Drought & Water Scarcity

In addition to driving heat waves and wildfires, climate change creates more frequent, longer, and more severe droughts. The Southwest has been hit especially hard, and is experiencing its most persistent drought in over 1,200 years. (Intense rainfall in recent months has brought relief to parts of California, but has not ended the drought entirely.)

Rising temperatures have a direct impact on the water cycle and the hotter it gets, the drier the landscape can get. This can eventually lead to extreme drought. Droughts affect not only surface water like lakes and rivers, but also the groundwater that is stored in aquifers and the soil. Groundwater is mostly rainwater and snowmelt that’s captured in spaces below ground, where wells can tap it for drinking water. But once that water gets used up, the dry ground sucks the surface water downward.

WATCH: HOW SEWAGE BECOMES DRINKING WATER

One place that has dealt with a water shortage is Orange County, California, whose growing population was already straining its groundwater supply by the late 1990s. And because Orange County is on the coast, its groundwater aquifer is connected to the ocean, which means that when groundwater is depleted, salty ocean water can replace it. With a water system nearing its breaking point, the county turned to a surprising source: wastewater.

“Wastewater is anything that you generate in a home that ends up in the drain. That includes the toilet, the washing machine, the sink,” Mehul Patel, executive director of operations at the Orange County Water District, told NOVA. This approach uses a process called reverse osmosis to push the wastewater through tightly wrapped membranes that filter out the impurities like pharmaceuticals, viruses, and salts. Residents in Orange County, California, have been using this recycled wastewater as an abundant and nearly drought-proof source of drinking water for years. 

Hurricanes

While climate change can cause extreme weather tied to heat, it can also cause extreme weather tied to wetter conditions. Today, during hurricane season, the Gulf of Mexico is about one to two degrees warmer than it was in the 1980s. And that warmer water supercharges storms. Research suggests that hurricanes are both becoming stronger and moving more slowly over land.

It might seem counterintuitive, but the deadliest part of a hurricane isn’t wind, but storm surge–ocean water that’s pushed toward shore by a hurricane’s strong winds. And rising sea levels mean higher storm surges that increase the flood risk in coastal areas. In September 2021, Hurricane Ida hit southeastern Louisiana, causing a major storm surge. It’s estimated that Ida wiped out more than 75 square miles of wetlands and destroyed about 13,000 homes.

To counteract the wetter, stronger hurricanes wrought by climate change, Louisiana is working to protect its coast with efforts like releasing sediment into endangered wetlands, upgrading levees and seawalls, and installing new floodgates. But these large-scale projects will take years to complete, so in the meantime local organizations and tribes are working on cheaper and faster solutions. They’re bagging leftover oyster shells from restaurant kitchens and piling them in specific wetland areas to create breakwater reefs. These artificial reefs contribute to the natural oyster life cycle by acting as a breeding ground for new oysters. Right after birth, oyster larvae attach themselves to older oyster shells and begin creating their own shells. As the oyster beds grow in size and height, they weaken the waves before they reach the shore, helping protect land and slow erosion.

WATCH: WEATHERING THE FUTURE