Emissions slashed today won’t slow warming until mid-century

MUCH OF the international effort thus far to combat climate change has focused on cutting emissions of greenhouse gases, chief among them carbon dioxide. That is, of course, a rational approach. Global average temperatures are roughly 1.1°C warmer today than in pre-industrial times and CO is the main culprit. It and other greenhouse gases are produced when fossil fuels are burned to generate energy or power engines, in steel and cement-making, by farming and deforestation. In the long term, eliminating these emissions is the only sustainable solution for stopping the inexorable warming of the planet.But greenhouse-gas emissions do not cause an instantaneous rise in global temperatures, and neither does cutting them result in instantaneous cooling. Instead, it will take decades for today’s policy efforts to result in measurable impacts on global temperature—as illustrated in a study published this week in .