Perhaps it’s being forced to think about global matters and the dangers they pose, but the UK’s foreign secretary Philip Hammond, like his Conservative predecessor, both understands the risks of climate change and the urgent need to act.

In a powerful speechthis week, he said: “Taking action to combat climate change is the right thing to do - the conservative thing to do.” Hammond had deliberately picked a tough crowd: the American Enterprise Institute, the free-marketeers who have for years have turned ExxonMobil and Koch dollars into climate change denial.

But the most extraordinary aspect of the speech is the chasm between the arguments Hammond made in Washington DC and the actions of his colleague George Osborne at home.

Hammond was extremely clear on the costs of inaction:

Many of the losses caused by climate change could be irreversible, regardless of our resources. Unchecked climate change, even under the most likely scenario, could have catastrophic consequences – a rise in global temperatures ... leading in turn, to rising sea levels, huge movements of people fuelling conflict and instability, pressure on resources, and a multitude of new risks to global public health. The worst case is even more severe: a drastic change in our environment that could see heat stress in some areas surpass the limits of human tolerance, leaving as the legacy of our generation an unimaginably different and more dangerous world for our children and grandchildren.

The good news, Hammond said, is that many of the measures to reduce climate risk stimulate - not decimate - economic growth:

The global low carbon economy is already worth $6tn, and is growing 4-5% a year. In 2013, additions to the world’s renewable energy generating capacity exceeded those to the fossil-fuelled capacity for the first time ever. Not only that, but the growth in the low carbon sector of the UK economy is now outpacing the growth rate of the economy as a whole. In the UK, [these] firms employed over 460,000 people and contributed £45bn to the UK economy in 2013, an increase of almost 30% in just three years ... Our businesses in the UK are looking at these trends, and telling us that we should be a leader, not a back-marker.

The problem is that Osborne, despite any chancellor’s obsession with growth, appears determined to undermine the green economy. Since May, a catalogue of measures are ruining confidence in the sector and destroying jobs.

Support for both large scale and domestic solar power is being slashed, as are subsidies for biomass and biogas projects. Onshore wind farms, the cheapest green energy, are being blocked as are solar farms in the countryside. All this is happening just as the fast-falling cost of renewables means subsidies are close to no longer being needed: it is snatching defeat from the jaws of victory.

Not content with undermining renewables, the chancellor is also tilting the playing field by ramping up subsidies for oil and gas, the only G7 nation doing so, as well as overseeing hundreds of millions of pounds subsidising filthy diesel generators.

Back in Washington DC, Hammond’s vision was as clear and Osborne’s is smoggy:

The world is moving towards a low carbon economy; I would suggest that there may now be more risk in being left behind than there is in taking the lead ... Studies suggest that by stimulating greater innovation and efficiency, climate policies will increase our economic competitiveness.

Osborne’s response has been to scrap energy efficiency programmes without replacements and dump rules for future homes and offices to be zero carbon.

Of course, as a Tory, Hammond strongly believes in the market over regulation as the best tool for change. He said that, with signals like a price on carbon to correct market failures, the market can deliver:

Watch [the market] deliver solutions – as it has delivered solutions to every other problem we have faced and resolved in our history ... Moreover, a market solution is simple and gives business the certainty that they’re asking for. The Paris deal [at December’s UN climatye summit] is important because it will give all countries confidence in the direction of travel. It will level the playing field, confirm once and for all that climate action does not create competitive disadvantage, catalyse investment, and spur innovation.

Stirring words - maybe today’s Gordon Gekko’s will be soon be saying “green is good”. But what is the direction of travel Osborne’s actions are setting for the market?

The chancellor has imposed a carbon tax on renewable energy (which emits no carbon), has increased the tax on small, efficient cars and given huge tax breaks to oil and gas industry. The UK’s Green Investment Bank, set up to address a market failure, is to be privatised. The direction of travel is down a high-carbon dead end in a gas-guzzling SUV.

Like Hammond, prime minister David Cameron also made strong statements on climate change in the US recently, saying “the UK is determined to play its part” in delivering an ambitious global deal in Paris. Yet at home, actions are speaking louder than words.