Climate overshoot: the way back below 1.5°C

The world is entering the era of climate overshoot, due to years of governments' collective failure to cut emissions in line with science. But how high temperatures rise, for how long, and what global warming comes down to at the end of the century are still choices.

In this report, the first in a new annual flagship series, we examine the latest science to discern how overshoot will increasing climate impacts and risks, and distil the benefits of swift mitigation in terms of reduced impacts and risks. Although impacts fall hardest on the poorest and most vulnerable countries, notably small island developing states and Least Developed Countries, we show that all of the big emitters - China, the US, India, the EU, and more - will gain from adopting a path that minimises overshoot.  

We also show that is possible if governments act with the highest possible ambition, global warming can peak around mid-century at 1.7°C and return below (and potentially well below) 1.5°C by 2100. This involves primarily a rapid fossil fuel phase-out driven by electrification, renewables and energy efficiency, halving fossil fuel use across the whole global economy by 2035. Supplementary to this, and equally critical, are action to stop deforestation and restore ecosystems, cut methane emissions quickly, and scale up carbon dioxide removals.