Live Q&A: So now we've agreed to stop climate change, how will we pay for it?

In Paris last year 195 countries committed cutting emissions and reducing global warming. Join a panel on Thursday 4 February to discuss making these a reality

On Wednesday the United Nations urged global business leaders to double investment in wind and solar energy to $600bn (400bn) a year by 2020. The announcement comes one month after the Paris climate agreement, where nearly 200 countries agreed to dramatically cut emissions. This week UN secretary general Ban Ki-moon urged business leaders to act decisively to hasten the transition away from the fossil fuel economy - or they would put the historic accord in jeopardy.

But even if business leaders do reach this ambitious target, it only marks the start of the investment needed to meet the agreed 1.5 degree target. The International Energy Agency has estimated that to hit this taget the world will need to spend more than $16trn (10.55trn) over the next 15 years, to cover the costs of replacing coal and gas-fired power stations with emissions-free sources of energy such as wind, solar and nuclear as well as the costs for improving existing energy efficiency in homes and businesses.