Abby L. Harvey
GHG Monitor
11/7/2014
While carbon-negative technologies like biological carbon capture and storage and direct air capture cannot replace emissions reduction efforts such as traditional fossil-fuel CCS, they must be used in conjunction to meet global climate goals, Noah Deich, consultant for the Virgin Earth Challenge, and Michael Ashcroft, an associate with The Carbon Trust, said during an event hosted by the U.S. Energy Association this week. Referring to several climate change scenarios, Ashcroft explained that in order to stay below the globally recognized two degree limit in global temperature rise, carbon emissions would have to fall below zero by mid-century. “To us, this is incredibly scary, that if you look at the overwhelming number of scenarios out there if we want to prevent climate change, we’re going to have to go below zero at some point not too far into the future,” Deich said. “The [Intergovernmental Panel on Climate Change] is just assuming that there are technologies out there to do that in order to make their model solve, essentially.”
However, Deich and Ashcroft said that while carbon dioxide removal (CDR) technologies cannot replace emissions mitigation technologies in the effort to battle climate change, the technologies must be used in conjunction with each other. “It is a complimentary option to emissions mitigation. … Carbon removal really expands the family of players that could be interested in tackling climate change and offers a wider range of solution but the key part is that this problem is urgent,” Deich said, going on to stress the need for hastened advancement in the CDR industry. “We need to start developing these solutions today, even if we need them in several decades’ time because it just takes a long time to develop these energy technologies and in many regards we’re at the beginning of this journey.”
Bio-CCS Presents Well Researched Option
CDR technologies can take one of two forms, biological and chemical, and advancements in both areas are ongoing. The most well-known biological option for carbon removal is bio-CCS, which has been recognized by the IPCC as a necessary technology in future climate mitigation efforts. “The easiest answer in many ways is just to plant more plants, trees, crops, that increases the overall stock of carbon in the ground as opposed to into the atmosphere but there are many other ways that we can keep that carbon locked up in the ground, one of those ways is underground geologic storage, essentially taking those plants, burning them, capturing the CO2 and injecting that deep underground, essentially the same thing we do today for fossil fuel carbon capture and sequestration,” Deich said.
An added benefit to bio-CCS in the CDR realm is that there’s a large knowledge base already. “Another key benefit is that it uses technologies that we already have available or are currently in development. Ashcroft said. “We’re already doing biology, we’re already doing CCS it’s not that much of a leap to put these together.”
Further Development Needed
However, Deich said, CDR remains a very young industry and the wide array of technologies available come with a wider array of knowledge bases and cost estimates. “We have to start doing carbon dioxide removal development and investment today. None of these approaches are at scale today for reasons. Some, while they may be more economically viable than others, like some of the land management approaches, need a lot more work on the science front, and some of the scientifically proven ones, like this air capture system … there’s not a clear business case for that today,” he said. “In the future we’re going to need to figure out some suite of carbon removal solutions that is both cost effective and economically viable, as well as scientifically and technically proven.”
