ON October 31 world leaders will descend on Glasgow, Scotland, for the United Nations Climate Change Conference, or COP26, in a last-ditch effort to defuse the climate emergency by limiting global warming to less than 1.5 degrees Celsius. Reaching that level would still bring violent storms, deep flooding, gripping droughts and problematic sea-level rise, but it would avert even more severe consequences. Global temperature has risen by nearly 1.1 degrees C since the industrial revolution.