What now? Next steps on climate change

The Paris Agreement, adopted in December 2015, was a seminal moment in the world's struggle to fight climate change. 197 countries agreed to limit the rise in global average temperature to “well below 2°C above pre-industrial levels” and to pursue efforts to limit it to 1.5°C. But Christiana, who led those global climate negotiations as Executive Secretary of the UNFCCC, says the climate agreement was just a staging post in what remains a long, hard process. So what are the next steps?