Sir David King at Green Monday

The second keynote at this month's Green Monday provided much food for thought. Sir David King agreed with Jon Williams that population growth is a key challenge, fuelled by life expectancy increasing from 45 to nearly 80. Not only that but urbanisation means that these people will have increasingly higher aspirations, and that has to be balanced against the need to reduce greenhouse gas emissions. An 80% reduction is needed on average, so the change must be transformational, not incremental.

Energy is seen as a basic freedom but decarbonisation of the economy is essential, and necessity is the mother of invention. We will find ways but it will proably be the private sector that seizes the opportunity. As an example, if we only converted one 10,000th of the sun’s energy to power we would have enough to sustain a population of 9billion.

If we fail to accept the challenge of decarbonisation, the great powers will battle for resources. Sir David King considers that the Iraq war may have been the first example of this. The cost of that conflict is estimated at $3 trillion. It’s estimated that the global emissions trading scheme which emerged from Kyoto will be worth $1 trillion when it first goes global. If the US government had invested in finding alternative energy sources rather than going to war over oil, then we could be in a very different place now.

We need visionary leadership from the great powers, and we need them to mainstream climate issues. It's not about making freestanding speeches about climate change, but making climate part of every speech as a key part of government strategy.