What's the most urgent action we need to take in 2020?

Horizon asked a selection of scientists featured in the magazine last year for their opinion on priorities for 2020. READ: Prosperity is about more than money. But what else should count? '2020 is a super-year for international policy action,' said Sandrine Dixson-Declève, co-president of global think tank the Club of Rome and chair of an expert EU group on the economic and societal impact of research (ESIR). An oceans treaty will be agreed, biodiversity targets announced, it's the first opportunity for nations to increase their climate goals, and the start of the decade to scale action for the 2030 Sustainable Development Goals, she says.