As leaders gather at COP28 in Dubai to discuss the climate crisis and negotiate how the world will address it, we are considering one of the most important numbers in the field of climate change: 1.5C. You may have read it in the news headlines before COP28, UN climate talks, which took place this year in Dubai, United Arab Emirates. You may have heard of it as part of your country's climate pledge. You may recognize it from Climate Clock in New York's Union Square, a public art project and reminder of the urgency of the climate crisis. In any conversation about climate change, the figure of “1.5C” is rarely far from discussion. But when people talk about “1.5C”, what do they actually mean? How do we measure it? And where did the figure come from? Is it the right target to aim for? And if we overshoot it, will we be able to get back below 1.5C? Ahead of the Dubai climate summit, the documentary looks at some of the questions surrounding this key climate change target.

What does meeting the 1.5C threshold mean?

This means that by 2100, the average global surface temperature will have increased by more than 1.5°C (2.7°F) above pre-industrial levels. The 1.5 C threshold was the target value set in Paris Agreement of 2015, a treaty in which 195 countries committed to combating climate change. The agreement aims to limit global warming to “well below” 2°C by the end of the century and to “pursue efforts” to keep warming to a safer limit of 1.5°C. ( Martha Henriques).