When it comes to decreasing carbon emissions, renewable energy and carbon capture—aka trapping carbon from industrial fossil-fuel burning at the source—sometimes duke it out in the headlines. There are pros and cons on either side: Renewables produce little to no emissions but have high up-front costs. Carbon capture does remove CO2 at the source, but long-term storage options are uncertain. Plus, carbon capture has one thing that renewables don’t: It allows fossil-fuel interests to keep burning up emissions-heavy fuel with less guilt.
In a recent study published in the journal Environmental Science & Technology, researchers pitted these two options against each other to see how the approaches compare in terms of cost, human health, energy needs, and, of course, climate change mitigation—and the results are clear.
Renewable energy takes the gold every time
To get at their answer, the researchers modeled out three scenarios: First, every country in the world replaces all fossil fuels with renewable wind, water, and solar energy. Second, the world goes all-in on carbon capture but continues to get the same amount of its energy from dead-dinosaur-related sources as today. Third, we all implement a combo of the two technologies.
Renewables proved to be the better choice across every metric. The renewables-only scenario completely eliminated deaths from air pollution (right now, 5 million die from air pollution each year). It reduced annual energy costs by 60%, and social costs (this accounts for expenses from energy, health, and climate) by 92%. It would only take six years for the cost of switching to renewables to be paid back by reductions in energy cost, results that are consistent with previous models). The payback period for social costs alone would be less than one year.
Switching to renewables and electrifying all energy also reduces the amount of juice needed to run the world. That’s in part because technologies like electric heat pumps and vehicles are more efficient than internal combustion engines, conventional air conditioners, and gas heaters and appliances. Making the switch also saves energy because it eliminates the need to expend energy extracting, transporting, and refining fossil fuels.
On the other hand, in either scenario involving carbon capture, air pollution is still an issue. Carbon capture also doesn’t trap non-CO2 greenhouse gases like nitrous oxide and methane, a greenhouse gas 28 times more potent than CO2. These emissions pose serious health and climate risks on their own. Even going the combo route has a social cost between 9 and 12 times higher than using renewables alone.
What this means for policymaking, and everyone at home
The study represents extreme, all-or-nothing scenarios that are all-but impossible because of the amount of international cooperation such a global shift would require. Not to mention that many analyses say that implementing a range of climate solutions is the most likely way we’ll actually be able to limit global warming. But, the study still demonstrates just how much more worthwhile long-term investment in renewables is compared to carbon capture.
At the core of these findings is a truth we all know so well: To keep the bathtub from flooding, we’ve got to turn the tap off. “The only way to eliminate all air-pollutant and climate-warming gases and particles from energy is to eliminate combustion,” the authors write in the study. For policymakers, that means the priority must be phasing out fossil fuels.
For the average person, this study serves as a reminder of the importance of investing in renewables in whatever way you can—whether that’s by installing solar panels, purchasing your home energy from a green supplier, or supporting groups that finance wind, water, and solar projects, such as the Center for Sustainable Energy and the Environmental Defense Fund. Keep an eye out for greenwashing traps set by fossil-fuel interests. If it sounds too good to be true, like Audi using carbon capture to reach its carbon neutrality goals, it probably is.