(CN) – Completely offsetting the effects of burning coal for electricity in the United States would require covering 89 percent of the nation in forests, according to a new study.
Burning coal to create electricity puts carbon into the atmosphere and has been shown to affect climate change. One way to offset that carbon production is to sequester the carbon in the ground or use nature to absorb it. Trees and vegetation are effective at sequestering carbon.
Michigan Technological University researched how much land would be required to plant trees and crops in order to offset greenhouse gases created by the U.S. coal industry, then it compared these techniques to how much sequestration would be required to offset greenhouse gasses in the production of solar panels.
The study, published in Scientific Reports, said a coal-fired generator that creates one gigawatt of electricity – enough power for about 700,000 homes – would require a new forest larger than the state of Maryland to neutralize all the carbon it emits.
Coal-fired power plants, which burn coal to produce steam that drives electrical turbines, require 13 times more land to be carbon-neutral than the manufacturing of solar panels, according to the Michigan Tech study. The United States would have to cover at least 62 percent of its land with crops, or 89 percent with forests to make coal carbon-neutral, the study showed.
By comparison, photovoltaic solar panels would require 13 times less land to become carbon-neutral and five times less than the best-case coal scenario, the study said.
Since the 1940s, the global economy has released about two trillion tons of carbon dioxide into the atmosphere, largely from burning fossil fuels, according to the Center for Carbon Renewal.
“We know that climate change is a reality, but we don’t want to live like cavemen,” Joshua Pearce, professor of material sciences and electrical engineering at Michigan Tech, said. “We need a method to make carbon-neutral electricity. It just makes no sense whatsoever to use coal when you have solar available.”
But replacing America’s coal-power infrastructure with solar power requires increasing solar’s capacity nearly 330 percent – from 22.7 gigawatts to 755 gigawatts – at a cost of $1.5 trillion, researchers at Michigan Tech said in a previous report.
Solar power has come down “radically in cost,” Pearce said, and when combined with natural gas-powered plants, “we have ways to produce all the electricity we need without coal, period.”
Carbon capture can also be accomplished through technology, which is what Klaus Lackner has pioneered at the Center for Negative Carbon Emissions.
Lackner has engineered “direct air capture” of carbon, using devices the size of shipping containers. Those systems mimic the work of trees by breathing in excess carbon in the air and exhaling it back out at normal levels.