No trees plant in Texas will capture 500,000 tons of CO2 a year and pump it underground beneath the Texan plains to fight climate change. David Appkin: The challenge is that it's very, very expensive, much more expensive than planting trees - but whole your freedman explained how this approach could end up cheaper and more reliable over time. He says there are dozens of startups with different kinds of approaches; Occidental has made a commitment to not just one of these plants, but to 130 of them.