evidence: The world is already more than 1 °C warmer on average than it was before industrial times, owing to greenhouse gases released from human activities. And that value is rising. The Intergovernmental Panel on Climate Change (IPCC) projects that there is at least a 50% chance that long-term global warming will overshoot 1.5 °C in the next decade, even with ambitious emissions cuts. [...] Source: analysis by R. A. Betts et al. [...] We encourage the IPCC to tackle this issue in a Special Report ahead of its seventh assessment report (AR7), which is not expected to be published until about 2030 — by which time, global warming might already have exceeded 1.5 °C or be close to doing so.