Leonardo DeCaprio voiced his concern about climate change earlier today at the UN Climate Summit, addressing 120-odd presidents and prime ministers from across the globe. Although reining in global warming has become a political priority, governments are persistently averse to providing estimates of how much carbon a policy saves. DiCaprio urges governments around the world to take decisive, large-scale action. In my opinion, the strongest point made during the speech is more on a positive note, when DiCaprio elucidates why renewable energy is not only achievable, but also good economic policy. He argues: "the economy itself will die, if our ecosystems collapse." Few nations realize the demographic dividends to be reaped from a healthy population or the long -term benefits of a stable environment.

The key issue remains, the pre-emptive measures to mitigate the risks of climate come at a high price - China, America and the European Union spend $140 billion a year on subsidising renewable energy. But can we afford to - in DiCaprio's words - 'pretend' climate change is a fictitious problem? Can we afford to live on the tip of the iceberg, oblivious to the anthropocene? Can we afford to put a 'price tag' on the future of our planet?