As a good liberal, I’m always keen to give people the benefit of the doubt. When newly installed Prime Minister David Cameron promised back in 2010 to preside over “the greenest Government ever”, I was delighted, if a tad sceptical. Then, last winter, he was said to want “to get rid of all this green crap” in relation to energy bills.

The last few months, and indeed days, have seen a continuation of this wild see-sawing between rampant scepticism and enthusiastic flag waving. Here are some high- and lowlights:

• 23 September 2014: To the UN, Cameron put forward a solid right-of-centre argument for a low carbon economy: “We need to give business the certainty it needs to invest in low carbon… we need a framework built on green growth not green tape.” This was probably the first major speech on climate change by a UK PM since Margaret Thatcher in 1990.
• 1 October 2014: To the Conservative Party conference, the green economy got the very briefest of mentions: “leading the way on tackling climate change”.
• 16 December 2014: He tells the Liaison Committee that people are “Frankly fed up with so many wind farms being built that won’t be necessary. Enough is enough and I am very clear about that.” He goes on to say he wants to phase out subsidies on renewables and talks up fracking instead.
• 17 December 2014: Prime Minister’s Questions: Cameron answers two questions on green energy, both times enthusiastically declaring that the green economy is creating jobs. In response to a third question he brags of having halved excess winter deaths from fuel poverty through insulating homes.

In The Green Executive, I posit that to deliver sustainability, we need leadership above all else. Paraphrasing leadership guru Warren Bennis, I listed 4 key leadership qualities:

• A sense of purpose;
• Trust;
• Resilience;
• Bias towards action.

It’s clear that on all of these things, Cameron’s performance is lacking. His sense of purpose is all over the place which impacts in turn on trust – and without trust, investors will hedge their bets, slowing progress. He shows little resilience and we could do with a lot more action rather than a constant wrestling match with his much greener Liberal Democrat coalition partners (usual disclosure: I’m a member of the Lib Dems).

The strangest thing of all is that, despite this, the UN recently ranked the UK third in the world for its efforts in tackling climate change, so Cameron could justifiably say he had delivered on his promise. But just imagine what we could have achieved if he showed a bit of leadership!