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As heat waves get worse, these fixes will help keep your home cool and energy efficient.
July 2023 will almost certainly be declared the hottest month ever recorded, but it is unlikely to hold that record for long. Climate change is making heat waves more frequent, intense, and longer-lasting across the U.S.
Adapting to this hotter future is often discussed at the scale of a city; measured in early warning systems, green spaces, and cooling centers. But there’s also a lot that individual homeowners can do to help their communities and protect themselves.
While the vast majority of American households — some 88% — use air conditioning for relief, homeowners would be wise to consider a variety of additional, “passive” cooling techniques. These are strategies that can keep your home at a safe temperature during a heat wave if the power goes out, an increasingly likely scenario. They will also save you a bit of money on energy bills. In a sense, adapting your home to extreme heat is just another way of thinking about how to make it more energy efficient.
These retrofits also have wider benefits. Since air conditioners work by transferring heat from inside your house outdoors, these fixes can cool down your neighborhood. They’ll cut carbon emissions and air pollution by lowering demand for electricity. If widely adopted, they’ll also help prevent blackouts and could shrink the amount of renewable energy projects that need to be built to replace fossil fuels, alleviating pressure on conservation.
I spoke with Steve Easley, a building science consultant who specializes in energy efficiency, and Shawn Maurer, technical director of the Smart Energy Design Assistance Center at the University of Illinois, about how homeowners should prioritize their options when it comes to passive cooling.
“I always recommend that people do a home energy audit from a certified HERS rater,” Easley told me, referring to the Home Energy Rating System, a nationally recognized system for inspecting and calculating a home’s energy performance. The auditor will tell you how leaky your house is, and how well your roof insulation, windows, and other parts of your house are working to keep out heat, and help you figure out what to attack first. (Easley also recommends getting at least three quotes for any of these solutions, because different contractors bid this work out very differently.)
Below are five things you can do to improve your home’s resilience to heat. Depending on a number of factors — such as where you live, how your house is constructed, and the condition it's in — the mileage you can get out of each of these measures will vary. The good news is that the federal government and many state governments offer tax credits and rebates for most of these solutions. The Inflation Reduction Act created the Energy Efficient Home Improvement tax credit, which offers homeowners up to $1,200 per year to spend on energy efficiency improvements. As part of that, you can claim $150 simply for getting an energy audit.
Maurer said the very first thing he would do to improve the efficiency of a home is to seal up any cracks where air can get in — for example, along the edges of the floors, around the windows, and in the ceiling around light fixtures. “That carries in moisture, heat, and everything from outdoors into the house. It's going to offset any air conditioned air you got inside the house. So air leakage is usually the place we recommend to start,” he said. “And then from there, it's what your budget can handle as far as adding more insulation to your house.”
Insulation comes in a wide range of materials, such as fiberglass and rock wool, blown cellulose, and rigid foam boards. It can be blown into your walls, installed on the floor of the attic, or underneath your roof deck. It’s a jack-of-all-trades when it comes to energy efficiency, since it keeps heat inside in the winter and blocks it from entering in the summer. That means it’s a great option for those in colder climates that also want to prepare their homes for hotter summers.
A 2021 study by a group of researchers at Lawrence Berkeley National Lab modeled the efficacy of a wide array of passive cooling measures in low-income homes in Fresno, California. It found that roof insulation, along with solar-control window films, which we’ll get to in a moment, were the two most effective ways to keep heat from entering the buildings. However, the authors note that roof insulation is an expensive major retrofit, and recommend that it only be done when the roof needs replacement.
A good first step might be finding out what kind of insulation you already have. The most important metric when it comes to insulation is called “R-value,” and the higher the number, the more effective it is. Older homes may have attic insulation as low as R-13, whereas modern building codes typically require insulation between R-38 and R-60.
The new federal tax credit offers up to 30% of the total cost of a project for air sealing and insulation, maxing out at $1,200 total. (Labor costs are not covered by the credit.)
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Having a light-colored roof and exterior will most certainly keep your home cooler than darker options, but not all light colors are created equal. “Cool” roofs and walls are made with special materials that reflect solar energy back into space, preventing it from being absorbed by the building. They also have high “thermal emittance,” meaning they release a lot of the heat that they do absorb, rather than sending it indoors.
All kinds of materials have been developed with these properties. For roofs, there are tiles, shingles, membranes, liquid coatings, and products made of slate, wood, and metal.
Cool roofs don’t necessarily have to be white, although the color does work very well. According to a database maintained by the Cool Roof Ratings Council, the most effective products tend to be bright white coatings, but there are also gray, green, blue, brown, and tan products that are rated highly.
For reflective walls, the most effective products similarly come in white and other light-colored paints, which can reflect 60 to 90 percent of sunlight when new. An extensive 2019 study of reflective wall paints by the same group at Lawrence Berkeley National Lab found that cool walls can reduce annual energy use in single-family homes in warmer U.S. climates by 2% to 8.5%.
Easley said it’s worth considering a cool roof if you have a central air conditioning system in your attic. Otherwise, attics in places like Arizona can get upwards of 130 degrees, taxing the equipment and forcing it to work harder. If your attic isn’t home to your AC, it may only make financial sense to do this kind of retrofit if your house is already in need of a new paint job or your roof needs work.
But it’s probably not worth considering a cool roof if you live in a colder climate, like the Northeast and upper Midwest, since cool roofs can actually make it colder inside in the winter.
There’s no federal incentives for cool roofs, but several states and utilities offer rebates.
This is a big category, and it’s easy to get overwhelmed by the options. Starting with those that will likely cost the most to the least, you can:
•Replace your windows altogether.
• Add storm windows to the interior or exterior of your existing glass.
• Purchase films that can be applied to the existing glass to increase its reflectivity.
•Install external shutters or awnings that block the sun.
• Install interior blinds and curtains that block the sun.
Here’s a rundown of each option.
New windows: Replacing your windows can cost tens of thousands of dollars, so unless they are already in need of repair, you may want to hold off on that option. But when the day does come around, you’ll want to look for “Low-E” windows, which stands for low emissivity. The inside of the glass is coated with microscopic layers of silver that reflect heat while still allowing light to pass through.
Within that category, you’ll also want to look for windows that have what’s called a low “solar heat gain coefficient.” This measures how much heat is absorbed by the glass and transferred inside. It’s rated on a scale of 0 to 1. If you live somewhere that’s sunny year round like Arizona, you ideally want one rated 0.25 or lower.
Through 2032, homeowners can claim up to $600 in federal tax credits for purchasing Energy Star rated windows.
Storm windows: Rather than replacing your windows entirely, it’s far cheaper to install storm windows with Low-E glass, which basically involves bolting another window to the outside of your house. Storm windows have an added benefit of improving air sealing, eliminating drafts.
Film: An even lower-cost option is to look into films with low solar heat gain coefficients that can be applied to existing windows. However, Easeley warned that many manufacturers will void your warranty if you add films to your windows.
Shutters, awnings, blinds, and curtains: Exterior shutters and overhangs that block the sun from ever reaching your windows will generally be more effective than interior shades or blinds, but all of these measures can help. “Window blinds and curtains are really dirt cheap ways to control energy,” said Maurer. “It’s not a very good buffer, but it’s something.”
The Berkeley study on passive cooling measures notes that blinds moderately improve how much heat from the sun enters your home, but they can feel more effective by reducing the sensation of sunlight streaming into your house.
If you still have any incandescent lights, they can also be a significant source of heat. They should be replaced with LED lights.
Planting trees, climbing ivy, and other vegetation can also passively cool your house by shading both your house and any surrounding pavement. However, if you have solar panels, or plan to get them in the future, do not plant trees on the south side of your home as it may reduce the solar system’s effectiveness.
Maurer cautioned that if you do a bunch of work in your home to reduce your cooling needs, you’ll want to keep that in mind if you ever have to replace your air conditioner. He advised having a contractor come in to re-measure what size system you need, since doing a like-for-like replacement will probably be overkill and could result in it malfunctioning.
Read another helpful guide about heat:
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On exemptions, lots of new EVs, and Cyclone Alfred
Current conditions: A smattering of rainfall did little to contain a massive wildfire raging in Japan • Indonesia is using cloud seeding to try to stop torrential rains that have displaced thousands • At least 22 tornadoes have been confirmed this week across southern states.
The Trump administration said yesterday that automakers will be exempt from the new 25% tariffs on imports from Mexico and Canada – but just for a month. The announcement followed a meeting between administration officials and the heads of Stellantis, GM, and Ford – oh, to be a fly on the wall. As Heatmap’s Robinson Meyer explained, the tariffs are expected to spike new car prices by $4,000 to $10,000, and could hit internal combustion cars even worse than EVs, and prompt layoffs at Ford and GM. “At the request of the companies associated with [the United States-Mexico-Canada Agreement], the president is giving them an exemption for one month so they are not at an economic disadvantage,” Trump said in a statement. Stellantis thanked Trump for the reprieve and said the company “share[s] the president’s objective to build more American cars and create lasting American jobs.” Around 40% of Stellantis cars currently sold in the U.S. are imported from Canada and Mexico.
The Supreme Court has rejected President Trump’s request to withhold roughly $2 billion in congressionally-approved payments to the U.S. Agency for International Development for foreign aid work that has already been completed. On his first day back in office, Trump ordered a 90-day pause on all foreign aid so programs could be reviewed to ensure they align with his agenda. The administration then eliminated funding for the majority of USAID’s contracts, including at least 130 that related to climate and/or clean energy. This week’s SCOTUS decision was “a welcome but confusing development for humanitarian and development organizations around the world,” The New York Timesreported, “as they waited to see if thousands of canceled contracts would be restarted.”
Speaking of cars, there has been a lot of EV news in the last few days:
Rivian announced plans to expand internationally. CFO Claire McDonough also said the company is working “around the clock” to roll out the new R2, R3, and R3X models, with production for the R2 set to start early next year. She said international expansion plans would kick off after the R2 production ramps up.
Volkswagen unveiled the ID. EVERY1. The concept-car version of its ultra-affordable EV “will be the first to roll out with software and architecture from Rivian,” TechCrunchreported. Production is slated for 2027, and the car will start at around 20,000 euros (or $21,500). No word on a U.S. release, though.
The ID. EVERY1Volkswagen
Volvo showed off the ES90. What is it? Good question. “Some might say it is a sedan,” the company said in its press release. “Others will see a fastback, or even hints of an SUV. We’ll let you be the final judge – all we know is that the new, fully electric Volvo ES90 carves out a new space for itself by eliminating the compromises between those three segments, which puts it in a class of its own.” InsideEVscalled it the company’s “most advanced EV to date,” because it can charge for 186 miles of range in 10 minutes on a fast charger.
Cadillac introduced a very long electric SUV. The electric Escalade IQL will go into production this year. With an overall length of 228.5 inches, it will be the longest SUV, uh, ever. It’ll start at $132,695.
On a related note, Tesla sales continue to plummet worldwide. They were down 76% last month in Germany, with sharp declines across other European countries, too. In Australia, sales were down 72%.
Global sea ice levels were at an all-time low last month, according to researchers at the Copernicus Climate Change Service. Arctic sea ice cover was 8% below average in February, the lowest since records began in 1979, and “the third consecutive month in which the sea ice extent has set a record for the corresponding month.” Antarctic sea ice cover was 26% below average. “One of the consequences of a warmer world is melting sea ice, and the record or near-record low sea ice cover at both poles has pushed global sea ice cover to an all-time minimum,” said Samantha Burgess at the European Centre for Medium-Range Weather Forecasts. Melting sea ice contributes to sea level rise and ocean acidification, harms polar ecosystems, and creates a global-warming feedback loop by reducing albedo, which is the Earth’s ability to reflect sunlight back to space.
C3S
Forecasters are growing increasingly concerned about Cyclone Alfred, which is swirling off the coast of eastern Australia and is expected to arrive Friday or Saturday as a category 2 storm, or perhaps even a category 3. Alfred will be the first cyclone in 50 years to make landfall in this part of Australia. The storm has slowed as it approaches land, which means it will spend more time over very warm waters, soaking up even more moisture to dump on land. “The northeastern Coral Sea, where Cyclone Alfred formed, experienced the fourth-hottest temperatures on record for February and the hottest on record for January,” a group of climate change researchers wrote at The Conversation. Residents in and around Brisbane have been told to prepare to evacuate.
American drivers spent more time on the road last year than ever before, logging a record 3.28 trillion miles.
On boasts and brags, clean power installations, and dirty air
Current conditions: Strong winds helped spark dozens of fires across parched Texas • India’s Himalayan state of Uttarakhand experienced a 600% rise in precipitation over 24 hours, which triggered a deadly avalanche • The world’s biggest iceberg, which has been drifting across the Southern Ocean for 5 years, has run aground.
President Trump addressed Congress last night in a wide-ranging speech boasting about the actions taken during his first five weeks in office. There were some familiar themes: He claimed to have “ended all of [former President] Biden’s environmental restrictions” (false) and the “insane electric vehicle mandate” (also false — no such thing has ever existed), and bragged about withdrawing from the Paris climate agreement (true). He also doubled down on his plan to boost U.S. fossil fuel production while spouting false statements about the Biden administration’s energy policies, and suggested that Japan and South Korea want to team up with the U.S. to build a “gigantic” natural gas pipeline in Alaska.
On the same day as the speech, new tariffs on imports from Canada, Mexico, and China came into effect, triggering retaliatory duties and causing stock markets to plunge. Experts are busy trying to figure out what it all means for American businesses and consumers. As Heatmap’s Robinson Meyer explained, the tariffs are likely to make electricity prices go up, raise construction costs, make gas more expensive at the pump, and make new cars costlier. Fossil fuel firms aren’t thrilled. The American Gas Association said the 10% tariff on Canadian natural gas “indicates potential impacts totaling at least $1.1 billion in additional costs to American consumers per year.” Chet Thompson, CEO of the American Fuel & Petrochemical Manufacturers, said that “imposing tariffs on energy, refined products, and petrochemical imports will not make us more energy secure or lower costs for consumers.”
Commerce Secretary Howard Lutnick has implied Trump might lift these tariffs as soon as today, but TBD.
The Trump administration has ended a program that monitored the air quality at more than 80 U.S. embassies and consulates around the world, citing “budget constraints.” The program started in 2008 with the U.S. embassy in Beijing and expanded from there. The data collected, which was posted on the AirNow website, has been used in academic studies and credited with helping reduce pollution levels in the host countries, leading to better health outcomes. This move “puts the health of foreign service officers at risk” and could hinder research and policy, Dan Westervelt, a research professor at Columbia University’s Lamont-Doherty Earth Observatory, toldThe New York Times.
Clean power installations soared in the fourth quarter of 2024, sending total operational capacity above and beyond the 300 gigawatt mark, according to a new report from the American Clean Power Association. “It took more than 20 years for the U.S. to install the first 100 GW of clean power, five years to install the next 100 GW, and three years to install the most recent 100 GW,” the report says. Here are some takeaways:
ACPA
China plans to ramp up its efforts to rein in emissions, expanding its emissions trading system beyond power plants to to include industries such as steel, aluminum, and cement, Premier Li Qiang said in a report this week. “Li also confirmed China intends to continue to play a key role in diplomacy on emissions reduction, as the U.S. retreats from international cooperation,” Bloombergreported. The country plans to roll out major climate projects such as offshore wind farms, “new energy bases” across its deserts, with a goal of reaching peak emissions before 2030. China is the world’s largest emitter of greenhouse gases, and while it has been rapidly expanding renewable power generation, it also struggles to wean itself off coal.
The Supreme Court yesterday watered down the Environmental Protection Agency’s authority to regulate water pollution, siding with the city of San Francisco in an unusual lawsuit pitting the liberal hub against the environmental authority. In a 5-4 decision, the justices said the agency had overstepped its authority under the Clean Water Act when it issued permitting for a San Francisco wastewater treatment plant that empties into the Pacific. The permit included provisions that would have made San Francisco authorities responsible for ensuring the water quality in the Pacific met EPA standards. Justice Samuel Alito essentially wrote that the permitting rules were too vague. “When a permit contains such requirements, a permittee that punctiliously follows every specific requirement in its permit may nevertheless face crushing penalties if the quality of the water in its receiving waters falls below the applicable standards,” Alito wrote. The ruling will make it harder for the EPA to limit water pollution. Next up on the SCOTUS docket: nuclear waste!
Bernard Looney, the former CEO of oil giant BP, is the new boss of an AI startup that tells businesses how to cut their emissions.
A conversation with Resources for the Future’s David Wear on the fires in the Carolinas and how the political environment could affect the future of forecasting.
The Wikipedia article for “wildfire” has 22 photographs, including those of incidents in Arizona, Utah, Washington, and California. But there is not a single picture of a fire in the American Southeast, despite researchers warning that the lower righthand quadrant of the country will face a “perfect storm” of fire conditions over the next 50 years.
In what is perhaps a grim premonition of what is to come, several major fires are burning across the Southeast now — including the nearly 600-acre Melrose Fire in Polk County, North Carolina, a little over 80 miles to the west of Charlotte, and the more than 2,000-acre Carolina Forest fire in Horry County, South Carolina. The region is also battling hundreds of smaller brush fires, the smoke from which David Wear — the land use, forestry, and agriculture program director at Resources for the Future — could see out his Raleigh-area window.
Wear is also the co-author of a study by RFF and the U.S. Forest Service that came out in late 2024 and singled out the Southeast as facing a “particularly worrisome” rise in wildfire risk over the next half-century. I spoke with him this week to learn more about why the Carolinas are burning and what the future of fire looks like for the region. Our conversation has been edited and condensed for clarity.
When discussing fires in the American West, we often talk about how historic suppression efforts are responsible for the megafires we see today. What was the historic fire regime like in the Southeast? What’s going on to make it a hot spot for wildfires?
First, there are the similarities. Both Western and Southeastern forests, especially pine forests, are fire-adapted systems; they need regular fires to maintain health. Anything that takes those forests out of balance is a problem, and fire suppression is an issue in the East and the West, and especially in the Southeast. But forests in the Southeast are the most heavily managed forests in the country — perhaps in the world. In many cases, they’re regularly burned; the South does more prescribed burning than the rest of the country combined. It’s a very, very common practice in this part of the world.
So we shouldn’t be surprised that there is fire in Southeastern forests. There have been big, episodic fires in the South, though they’re not as common. There was the fire in 2016 in East Tennessee, from the Smokies into Gatlinburg, with a number of fatalities and lots of structures damaged or destroyed. There have been big fire years in east and west Texas. And there have been big fire seasons in Florida, though it’s been a while.
How is population growth in the Southeast adding to the strain?
We’re accustomed to talking about the wildland-urban interface in the West, but it’s also a big issue in the Southeast. Some of our urban growth centers in the Southeast include the Raleigh-Durham area, where I live, and Atlanta, Nashville, and Florida. These are generally flat landscapes, as well as very heavily forested landscapes. As the population grows out of the city centers, they go into pine and mixed-pine hardwood forests that are fire-adapted ecosystems. Then you have interspersed communities with forest vegetation, and that’s a big issue.
I also read in your report that much of that land is privately owned, which makes management tricky.
Private ownership is about 89% of forests in the South. [Editor’s note: By comparison, only about a third of forests in the West are privately owned.] Even where you have public ownership, a lot of that is by the Department of Defense and concentrated in a couple of different areas in the Ozarks and southern Appalachians. Much of the landscape in the coastal plain and Piedmont — which is most of the South — is predominantly private ownership.
There’s a distinction to be made between commercial owners, like timber investment management companies or real estate investment trusts, who actively manage landscapes. With timber harvesting, there are a lot of risk mitigation activities and a lot of prescribed burning. But then you have over a million non-industrial private landowners with small holdings. If you’re trying to coordinate any kind of wildfire mitigation scheme using fuel treatments and the like, it requires some work.
Horry County, South Carolina, and Polk County, North Carolina, were not part of your paper’s list of counties vulnerable to wildfire. I’m curious if you think what we’re seeing now says something about the limits of the study and the data you had available, or if you have another takeaway about what’s going on.
Importantly, our study looked at long-term averages. Throughout the South, there is a fire regime, and in any given year, it is possible to have wildfires of consequence. I would point out that we were especially concerned this year because Hurricane Helene laid down an awful lot of trees and created a fuel load.
We’re also entering one of the two fire seasons in the South. Wildfire is most predominant in the spring and in the fall; it’s at those times when temperatures begin to rise but humidity remains low, and there are extended dry periods that allow the fuels to dry out. You have warm temperatures and wind in the spring, setting the stage for wildfire. Typically, that window will begin to close at the end of April because it’s pretty darn humid in the South at that point, and it’s much less likely that fuels will get dry enough to carry a fire.
The same thing happens in the fall: Temperatures may remain high, and if we don’t have a lot of precipitation and humidity — usually in October and into November — then you have the conditions right for fire. But as the climate shifts, we see the length of those seasons growing to the point where the fall is approaching the spring. Wildfires in January and February indicate that these two seasons are growing toward one another and providing a much longer season. Our paper showed that, when you account for climate change across all of those global climate models and representative concentration pathways, the windows for more wildfire activity and more intense wildfire activity are expanding.
Your paper cited wildfire risks across the Sun Belt. Today, the National Weather Service is warning of “potentially historic” fire conditions in central Texas. Can local emergency managers use your modeling to prepare for such situations?
Things like the year-to-year fire projections and the day-to-day forecasts best serve local emergency managers. Wildfire in the South is determined by the drying of fuels and temperature and humidity conditions, which vary daily. If we look over the last week, Saturday was beautiful in the Carolinas. It was sunny, in the 70s, dry, and a little windy. That was the day [hundreds of] fires started across the Southeast. And the next day, there were very few new fires. Mid-week projections of wildfire potential in the Southeast show that it’s really low, with the exception of Texas. It changes day to day, driven by fine-grain weather forecasts, and that gives emergency managers some insight into where they might want to pre-position crews or do pre-suppression activities.
What we’re doing with the modeling is asking, What is this going to look like in 50 years? The takeaway is that wildfire activity is going to remain strong and perhaps grow in the West, but the big structural change is really strong growth and active fire in the Southeast, where you have wildfire and wildlands proximal to millions of people and more vulnerable communities. It’s a fire regime that’s going to affect more people.
I also wanted to ask about the USDA Forest Service’s contributions to your paper. Do you think research like this could still happen today, given the Trump administration’s efforts to eliminate anything climate-related from the federal agenda?
I came to Resources for the Future six years ago after a long career with the Forest Service, so it’s hard for me to remain a dispassionate scientist here. I think we need to see how the dust settles. It’s hard to imagine a future where the agency and federal government do not have a high level of concern regarding fire — and I don’t think you can do any kind of effective planning, or thinking about the future, or targeting of activities without understanding how climate is likely to impact these disturbance regimes.
I don’t have the crystal ball that many people are seeking right now. We’ll have to wait to see. But our research demonstrates the vital role of understanding climate dynamics, and it shows how critical weather forecasts are for people with boots on the ground who are trying to stay ahead of disaster.
Editor’s note: This story has been updated to reflect that about a third of land in the West is privately owned, not publicly owned.