Many companies’ plans to reduce their greenhouse-gas emissions to “net zero” rely heavily on technologies to capture carbon. Some are more speculative than others.
Nearly 1,400 companies have promised to cut their net carbon dioxide emissions to zero over the coming decades. So-called carbon offsets, where the gas is removed from the atmosphere, are central to many of these plans. The latest of the almost daily announcements: French oil giant Total said on Tuesday that it will plant a 40,000-hectare forest in the Democratic Republic of Congo to sequester 10 million tons of CO2 over 20 years.
Planting trees is a popular choice. Forests absorb CO2 from the atmosphere and certification is well established. But there are drawbacks. The gas is released if they are cut or burned down. Land also is a limited resource, making many goals unrealistic. Greenpeace has estimated that the reforestation targets of just two companies—Italian oil and gas giant Eni and British Airways owner IAG—would use about 12% of land available for new forests globally by 2050.
Another widespread technique is carbon capture and storage, or CCS, where CO2 is removed from factory chimneys and pumped underground or stored in a solid form. The method has been around for decades, but until recently wasn’t widespread. The economics didn’t add up, partly because the carbon prices charged in Europe and the carbon-capture tax credit paid in the U.S. were too low.
That is changing as emissions become more expensive and as costs fall with improving plant design, construction and capture methods. CCS will be useful in producing cleaner hydrogen and in hard-to-green industries such as steel and cement. New, bigger facilities are being built at emissions hubs such as Rotterdam’s port, which cuts costs and increases utilization.
