Governments will agree this year that Sustainable Development Goals (SDGs), for the period to 2030, and a new global climate agreement, will take effect from 2020. Together, these could set the course for environmental sustainability and human well-being this century. The agreements together offer a once-in-a generation opportunity to end extreme poverty, create climate resilience and avoid dangerous levels of climate change by committing to zero net carbon emissions. This policy brief explores the relationship between the level of ambition in the SDGs and the level of ambition in the global climate agreement. It aims to provide decision-makers and negotiators at the 21st Conference of the Parties of the United Nations Framework Convention (UNFCCC COP21) with a better understanding, and quantitative evidence where possible, of the implications of the outcome of the climate agreement on the SDGs. In addition, the research aims to influence the SDG negotiations because, although the goals are unlikely to change from those set out in the latest draft list, the targets and indicators are still being adjusted. Moreover, countries are still negotiating their financial commitments to implement the post-2015 development agenda. This brief encourages governments and other funders to ensure that the SDGs and associated financing deliver climate compatible development in the poorest and most climate-vulnerable countries.