Эколог опроверг: вырубка деревьев под солнечные панели не уничтожает климатическую пользу проектов

Trees vs. Solar Panels: Getting the Carbon Math Right September 4, 2026 The seemingly endless debate in Rhode Island about clearing trees to put up solar panels reared its head again in a recent column in ecoRI News by Frank Carini, who wrote that “Bulldozing trees to build utility-scale renewable energy facilities — 4 megawatts, in this case — essentially eliminates any of the project’s climate benefits.” The article goes on to discuss very real concerns associated with clearing trees: loss of habitat, fragmentation of continuous forest, and water quality impacts. I’ve studied forests all over the world for the past 20 years, and I share these concerns. I completely agree with Mr. Carini that “Rhode Island needs to get serious about protecting the environment.” But let’s get the math right before we start the harder discussion about the tradeoffs that we have to make to address the climate crisis. Let’s start with the benefits a forest provides from a carbon perspective (these are not the only benefits — I’m just starting there). According to the U.S. Department of Agriculture’s Forests of Rhode Island, Rhode Island forests cover about 400,000 acres, and contain about 26 million “short” tons of wood above ground. (Carbon math is complicated by a number of unit conversions. The United States uses “short tons,” which is 2,000 pounds. The rest of the world, and scientists, use “metric tons,” which is 1,000 kilograms or 2,220 pounds. Also, some studies report the “biomass” of wood, which is literally how much it weighs, while others report the mass of carbon in that wood, which is about 50% of the total biomass. Either way, if wood is burned the carbon stored in it is converted to carbon dioxide. Carbon dioxide is a molecule that has one carbon atom and two oxygen atoms, and thus has a mass that is 3.67 times greater than carbon alone. Thus, a forest that has 60 short tons of biomass stores 60 x 0.91 = 55 metric tons of biomass, and 55 divided by 2 = 27.5 metric tons of carbon. If this forest is burned and converted to CO2, it releases 27.5 x 3.67, about 100 tons of carbon dioxide. For this article, when I say “tons” I mean “short tons.”) Of course, trees have roots in the soil, and roots typically add about 20%-25% to the mass, so let’s call it 32 million tons of wood. Spread over roughly 400,000 acres, that’s 80 tons of wood per acre, or 40 tons of carbon stored per acre, which if burned, would release about 150 tons of carbon dioxide. The numbers will be higher in older, more intact forests, and lower in younger, degraded forests. So, does clearing that forest for solar panels “essentially eliminate the project’s climate benefit” by turning all that carbon stored in trees into carbon dioxide in the air? To answer this question, we have to ask how long it would it take for solar panels, producing clean electricity and thus avoiding fossil fuel combustion at power plants, to make up for the carbon dioxide released during the initial tree clearing? Here’s the math: an acre of ground-mounted solar panels in Rhode Island produces about 260 megawatt-hours of electricity a year (more recent production data suggests this is a conservative estimate). Our utility grid relies heavily on burning gas to produce electricity, and thus releases about 0.27 tons of carbon dioxide for each megawatt-hour produced. Since solar displaces that gas, each megawatt-hour of solar-produced electricity reduces greenhouse gas emissions. In this example, multiply the 0.27 tons of carbon dioxide per megawatt-hour by 260 megawatt-hours per acre, and we see each acre of solar panels keeps about 70 tons of carbon dioxide out of the air each year (I’m rounding off my numbers because both the emissions from the grid and the amount of electricity the panels produce varies from year to year and with technology). Thus, in about two years, an acre of solar panels will make up for the release of carbon dioxide associated with land clearing. But wait, you might say, a forest isn’t static. It’s actively taking carbon dioxide out of the air. We also need to think about the carbon dioxide they would take up if we hadn’t cleared them. That’s true, but the number is small. An acre of average forest in Rhode Island takes a few tons of carbon dioxide out of the air each year. That’s far, far less than the 70 tons of carbon dioxide that solar panels keep out of the air every year. And solar panels last a long time, at least 20 years and typically more. Over that time period, an acre of solar panels will have kept 70 tons x 20 years = 1,400 tons of greenhouse gas pollution out of the air — the forest those panels replaced would have stored about 200. (Assuming the grid remains as dirty as it is today, which hopefully it won’t because we’ll agree to deploy massive wind and solar resources.) Thus, from a simple carbon perspective, cutting down trees to put up solar panels makes sense, at least right now, when our electricity production depends so heavily on fossil fuel combustion. But before we all sharpen up our chainsaws, let’s think more carefully about the context of climate change and the need for our energy transition off fossil fuels and onto renewables. For the first time since the Industrial Revolution, Rhode Island has the chance to generate its own clean, renewable, affordable power. We can free ourselves from fossil dependence and price spikes driven by geopolitical events by building our supply of affordable power, all while doing our part to fight the global challenge of climate change. Climate change is THE biggest threat to the environment in Rhode Island and across the world — full stop. And human energy use from burning fossil fuels is responsible for the lion’s share of the threat. While Rhode Island’s energy transition will not stop climate change, neither will climate change be stopped unless everyone participates. In my opinion, these facts make it clear we should devote a non-trivial amount of land for the deployment of renewables — there is no free lunch. If we are going to make the transition off fossil fuels, we will need tens of thousands of acres of solar panels across the state (plus hundreds of windmills offshore). There is no way to phase out fossil fuels without this scale of renewable deployments. Where should it go? A report prepared for The Office of Energy Resources suggested covering most of our parking lots, commercial and industrial sites, and brownfields could produce a substantial fraction of Rhode Island’s current electricity demand. Putting solar on these sites are is typically be more expensive than on undeveloped land, so for a given dollar spent we will get fewer renewables. In addition, putting solar on these sites will require assessments by thousands of property owners, review by the utility of each interconnection, and myriad other hurdles that will bring deployment to a crawl. Meanwhile our emissions continue unabated. And of course, if we are successful in reducing our emissions, our current electricity demand is much lower than it will have to be in the future as we electrify our cars, home heating, and industry. These sites alone will not suffice, even if we covered every one of them. Where else could we look? Rhode Island has about 60,000 acres of farmland, which has already been cleared (and thus the carbon from trees already lost). But opposition to putting solar on local farms appears even stronger than opposition to clearing trees. We also have over 5,000 acres of golf courses which only benefit the few who play golf, but I’m guessing covering them with solar wouldn’t go over well either. Of course, we also have 400,000 acres of forests. Is cutting 1% of them for solar panels acceptable? One-tenth of one percent? Ten percent? And who gets to decide which forest is too valuable to cut, and what is OK to sacrifice? Value is a human concept, and humans disagree about what is valuable. There is no scientific answer to these values-based questions. What is beyond debate is that our rapidly warming climate, caused by burning fossil fuels, is an existential threat for every ecosystem and habitat on the planet, and that only the widespread deployment of renewables can stop climate change. In Rhode Island it will take tens of thousands of acres of panels to kick our fossil fuel addiction. Where to put them is a debate we need to have immediately. There is no perfect solution; we are faced with a series of “less bad” choices. We are going to need to compromise with each other, and understand that one person’s forest sanctuary, or golf course, or business-critical parking lot, is another person’s ideal solar site. We’re going to need to weigh the speed of renewable deployment against the benefit of putting them in the “ideal” site. But let’s get the facts straight. Clearing trees for solar panels does not “eliminate the project’s climate benefits.” Stephen Porder is the Acacia Professor of Ecology, Evolutionary and Organismal Biology and Environment and Society at Brown University. He is also the co-founder of Possibly, a sustainability science podcast heard weekly on Ocean State Media, and the author of Elemental: Five elements that changed Earth’s past and will shape our future. All views expressed in this editorial are his alone, and do not represent those of Brown University.   Categories Join the Discussion View Comments Your support keeps our reporters on the environmental beat. Reader support is at the core of our nonprofit news model. Together, we can keep the environment in the headlines.