Countries will soon gather in Paris for United Nations climate talks — and hopes are high that the negotiations will produce a new agreement to reduce greenhouse-gas emissions. Countries have been submitting pledges that outline how they hope to limit their emissions, but many challenges remain.

Nature special: 2015 Paris climate talks

The precise form of the deal is still open to debate. Worse still, even if all countries stick to their pledges, it will put the globe on course for around 2.7 °C of warming compared to before the industrial revolution — a sizeable overshoot of the 2 °C limit that negotiators are aiming for.

In this video, Nature reporter Adam Levy examines the political backdrop to the Paris talks.

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