GLASGOW, Scotland – The U.S. Department of Energy on Friday unveiled its biggest effort yet to drastically reduce the cost of technologies that suck carbon dioxide out of the atmosphere, in a recognition that current strategies to lower greenhouse gases may not be enough to avert the worst effects of climate change.
At the United Nations climate summit, Energy Secretary Jennifer Granholm said her agency would invest in research in the nascent field of carbon removal, with a goal of pushing the cost under $100 per ton by 2030. That's far below the price tag for many current technologies, which are still in early stages of development and can cost as much as $2,000 per ton.
The ultimate aim is to identify techniques that can remove billions of tons of carbon dioxide already in the atmosphere and permanently store it in places where it won't warm the planet.
The idea of pulling carbon dioxide out of the atmosphere, once considered the stuff of science fiction, has attracted increasing interest in recent years.
Hundreds of countries and companies have now pledged to reach "net zero" emissions by midcentury, essentially a promise to stop adding greenhouse gases to the air, to limit global warming to 1.5 degrees Celsius above preindustrial levels. That's the threshold beyond which many scientists say the planet will experience catastrophic effects from heat waves, droughts, wildfires and flooding The planet has already warmed by about 1.1 degrees Celsius.
But reaching net zero may require two strategies. First, countries will have to deeply cut their emissions from burning oil, gas and coal in power plants, factories and cars, and to switch to cleaner sources of energy. But they may also need to remove carbon dioxide from the atmosphere to offset emissions from sources that are difficult to clean up, such as agriculture.
The U.N.'s Intergovernmental Panel on Climate Change estimates that the world may ultimately have to remove 100 billion to 1 trillion tons this century to stay below 1.5 degrees, in part because countries have been so slow to reduce their emissions.
Current techniques are no match for the challenge. One popular option is to plant trees, which naturally absorb carbon from the air. But trees take years to mature, there's only so much land available and forests can burn in wildfires, releasing carbon back into the atmosphere.
