Michael Irving / New Atlas
IN MAY some 250 scientists and policy types from around the world convened in Gothenburg, Sweden, to discuss a dirty secret of the three-year-old Paris climate agreement. Virtually all simulations which chart paths toward meeting that compact’s goal—to keep temperature rise “well below” 2°C relative to pre-industrial levels—assume not just a sharp reduction in actual emissions but also the removal of carbon dioxide from the atmosphere on a massive scale. One reason such “negative emissions” have been absent from climate discussions—the Swedish shindig being the first of its kind—is that no one has a good idea of how exactly to bring them about. The obvious solution is to plant lots of trees, to convert CO2into wood. But this would mean foresting an area with a size somewhere between that of India and Canada. Alternative, engineered fixes have been dogged by potentially stratospheric costs, uncertain efficacy or both.
One of the possible pathways to limitless and clean energy can be found in hollow, doughnut-shaped chambers known as tokamak nuclear fusion reactors. A relatively new player on the scene, a UK company called Tokamak Energy, is claiming a new milestone in the area after heating its ST40 device to 15 million degrees Celsius, similar to temperatures found at the center of the Sun.