This is a grand challenge of our time because the capacity of the Earth’s atmosphere to safely hold excess carbon without too much warming is limited. The pace to transform economies away from dumping fossil carbon into the atmosphere will likely be too slow to achieve the goal of holding the temperature increase to two degrees Celsius.
Unless that pace is dramatically accelerated, the planet will almost certainly exceed its “carbon budget” within two decades, if it hasn’t already. This concern has led the International Panel on Climate Change (IPCC) to conclude that Negative Emissions Technologies (NETs), which remove CO2 from the air, will be needed to meet climate goals.
However, NETs are still in the research, development or demonstration stages of commercialization and may not be ready in time, or feasible at the necessary scale. That poses a conundrum. Technologies cannot develop without policy drivers; policy cannot lead the way without the assurance of demonstrably affordable and scalable technologies.