Carbon capture has existed for decades, but some recent efforts seek to lower the costs of the process. Climeworks’s CO2 collection system in Hinwil, Switzerland. Can new technology suck carbon dioxide, a prevalent greenhouse gas, out of the air—economically? More companies are betting that it can, as governments adopt ambitious carbon-emissions targets and investors grow increasingly concerned about the risks of climate change . Carbon-capture techniques have existed for decades. But it’s incredibly expensive—not to mention energy intensive—to remove the carbon dioxide from the atmosphere on a large enough scale to make a significant dent. Now, Exxon Mobil Corp., Microsoft Corp. and others are focused on reducing the cost and the amount of energy required to capture carbon dioxide. Some companies are using giant fans to suck up air, then separating the carbon dioxide chemically. One venture plans to fill land in Arizona with dozens of accordionlike machines designed […]