This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
A bipartisan group of senators recently introduced a bill that aims to combat climate change by providing funding for research into “negative-emission technologies,” which take greenhouse gases out of the atmosphere and store them underground.
But there’s a small problem: These experimental technologies aren’t very effective—and probably never will be. Investing in these moon shots would divert resources from proved emission-reduction initiatives. By the time we realize our gamble has failed, it will be too late to prevent the worst consequences of climate change.
American lawmakers aren’t the only ones betting on negative-emission technologies. The 2015 Paris agreement, a pact supported by every nation except the U.S., is banking on tech to help prevent global temperatures from rising more than 2 degrees Celsius above preindustrial levels.
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These technologies are largely theoretical. One of the most prominent is “bioenergy with carbon capture and storage,” or BECCS. The strategy envisions a future wherein humanity burns grasses, trees and other vegetation at power plants—and then sequesters the emissions underground, where they’d stay trapped in mineral formations.
An analysis conducted by Stanford University climate scientists found that expecting BECCS to meet the goals of the Paris agreement is wishful thinking. Growing the plants needed would require an area double the size of India. That would divert huge swaths of land currently used for agriculture and disrupt communities throughout the developing world.
Another analysis, published in Climate Change, revealed several ecological factors could render BECCS impractical. For example, BECCS would require huge amounts of freshwater. More than 1.2 billion people currently live in water-stressed areas. Growing all that biofuel would rob communities of their already limited water supplies.
Another negative-emission technology, known as “direct air capture,” is even more pie in the sky. The technology involves pumping air through a filter to trap carbon and store it underground. Climeworks, a Swiss company, has constructed a direct air capture facility near Zurich. The firm estimates 250,000 such plants would be needed to remove just 1 percent of annual global carbon dioxide emissions. So even if the technology works flawlessly and becomes orders of magnitude cheaper, it would barely affect atmospheric greenhouse gas levels.
Devoting huge amounts of time, money and energy to speculative technologies is not just wasteful. It also provides a false sense of security—that we have ample time to wait for essentially magical technologies to make up for the emissions of the present.
Climate change is already causing severe harm worldwide. Undoing the damage will require cutting carbon emissions immediately.
Island nations are especially vulnerable to the rising sea levels and volatile storms caused by climate change. Last year the Caribbean faced three of the most expensive hurricanes ever recorded. According to forecasters at Colorado State University, this year’s hurricane season will be just as vicious.
Warmer global temperatures, meanwhile, have produced longer and more severe wildfire seasons. And they have fueled the spread of animal-borne illnesses like the West Nile and Zika viruses.
Fortunately, there are several simple steps we can take to reduce emissions now: We can start by tweaking our diets. Livestock account for roughly 20 percent of all greenhouse gas emissions. A study by University of Oxford professors found curtailing meat consumption to the level recommended by standard health guidelines could cut food-related emissions nearly 30 percent by 2050. Excise taxes on meat could also prod consumers to eat less of it.
Widespread adoption of electric vehicles could reduce carbon pollution by 430 million metric tons annually by 2050. That’s about the same amount of emissions produced by 80 million traditional cars. Such a shift isn’t far-fetched. A Bloomberg analysis projects electric cars will be cheaper and have lower lifetime costs than traditional cars within the next decade. They’ll account for more than half of new car sales by 2040. Tax credits for buyers of electric vehicles could speed this adoption.
These solutions are proved. Yet too many in the scientific community have acquiesced to the idea big emissions cuts are politically impossible—and only technology can save us. But by promoting unproved emissions-reduction technologies, the community has given politicians inappropriate intellectual cover to put off the cuts we need.