Carbon removal is the subject of this episode and Tucker welcomes one of the world’s leading experts on the subject to bring us up to speed on the technological advances happening in this part of the climate change conversation.
Dr. Sabine Fuss is an economist at the Mercator Research Institute on Global Commons and Climate Change in Berlin. She was also part of the original United Nation’s Panel on Climate Change to assess the science, risks and impacts of global warming.
After the panel’s 2018 report and the new Paris Agreement goal to keep global warming to 2.7 degrees Fahrenheit (1.5 degrees Celsius) or less, Fuss was tasked with finding out which carbon removal strategies were most promising and feasible.
Fuss originally worked on climate change mitigation. The longer serious climate action has been delayed, she realized the more important carbon removal has become and it turned into the focus of her research.
Fuss says it makes sense that a trained economist is one of the leaders in the carbon removal conversation. Since climate scientists have come to a consensus that climate change is taking place, she says it’s only natural that climate change mitigation has become an interdisciplinary problem. Economists have become necessary not only to assess costs and benefits but also to work out the right incentives and policies.
Importance of Carbon Removal
Fuss says we have a certain carbon budget and amount of CO2 that we can emit to the atmosphere before we cross a certain threshold where it will be difficult to avert global warming. According to Fuss, we have been progressively depleting this carbon budget and we have not managed to it turn around to decrease emissions.
Dr. Fuss takes us through the different types of carbon removal in this episode and which forms are showing the most promise.
Afforestation and reforestation. Planting or replanting of forests are well known natural carbon sinks. Vast numbers of trees can sequester CO2 from the atmosphere for photosynthesis, a chemical reaction that uses the sun’s energy to turn carbon dioxide and water into sugar and oxygen.
Fuss says scaling up nature-based carbon removal, like planting and replanting forests, require a lot of land that already may be in use and can conflict with other policy goals, like food production.
Direct air capture is a chemical process that takes carbon dioxide out of the air and binds it to filters. When the filter is heated, the CO2 can be captured and then injected underground. Fuss says direct air capture is a promising technology because it has a smaller land footprint than biomass plantations. She says direct air capture is something that we need to pursue as part of the mix to eventually get to carbon negative emissions.
Enhanced weathering uses natural or artificially created minerals which absorb carbon dioxide and transform it in other substances through chemical reactions. Like other forms of carbon removal, Fuss says enhanced weather has advantages and disadvantages. The clear advantage is that you don’t need new areas of land or land clearing for this practice. However, if you want to scale enhanced weathering to remove CO2 at a double digit gigaton scale, it would require grinding mountains of minerals and the problems that mining brings with it.
Fuss says it will take a sensible approach to carbon removal using different methods rather than believing in one silver bullet technology.
Fuss believes carbon pricing is what drives the roll out of carbon removal technologies and practices for climate stabilization. The idea is that each remaining ton of CO2 that’s emitted will pay for its own cleanup.