Limiting global warming to 1.5C will also require significant carbon dioxide removals, achieved either by nature-based solutions such as reforestation, or by capturing CO? directly from the air. Photograph: Lisa Maree Williams/Bloomberg In December, the COP28 climate conference will meet in Dubai. The event’s president, Sultan al-Jaber, has set the objective of agreeing actions that could limit global warming to 1.5 degrees. That will only be possible if carbon emissions from the energy system, currently running at about 34 gigatonnes a year, fall rapidly to reach net zero by around 2050. There are only two ways to achieve that: either...