collaboration. Net-zero. Those two words have become the near-universal language for policymakers intent on sealing a deal at the UN climate conference in Glasgow, Scotland in November. But are they the key to fulfilling the promises to hold warming to 1.5 C made at a similar climate summit in Paris six years ago, or, as some scientists and activists are now saying, are they a dangerous delusion to which climate scientists have become complicit? Achieving “net-zero” requires that any carbon dioxide or other greenhouse gas emissions are balanced by absorbing an equivalent amount of CO2 from the atmosphere — sometimes called negative emissions. More than 100 countries, including the biggest three emitters — China, the United States, and the European Union — have pledged to achieve net-zero targets in the coming decades. They are being applauded for finally getting a grip on climate change.