THERE is a great, big gaping hole in our debate about oil:

the urgent issue of the climate crisis. Many on the left support Scottish independence as they believe it is a chance to break with neoliberalism, a brand of capitalism we have lived under for the past 30 years, characterised by privatisation, deregulation, cuts in social spending and tax cuts for the wealthy, which they believe (rightly, in my view) has been a social and economic disaster. To think we can break with that while simultaneously worsening what the economist Nicholas Stern described as "the greatest market failure the world has seen" is absurd.

The climate crisis is a question of distributional justice like any other, but on a geographical and generational scale. We in the high-consuming, high-emitting west are stealing from the global south and future generations on a truly epic scale. To be clear about the scale and severity of the crisis: a recent major report from the World Bank (no-one's idea of a bunch of hippy eco-warriors) stated: "present emission trends put the world plausibly on a path toward 4°C warming within the century."

According to Mark Lynas, author of Six Degrees: Our Future on a Hotter Planet, this would mean the disappearance of the Arctic ice sheet, the spreading of desert across southern Europe and England experiencing summers in the mid 40s. How much can we extract, exploit and burn? The calculation should be subject to serious analysis from economists and climate scientists working collaboratively.

Here are some figures we need to bear in mind: according to Nasa climate scientist Professor James Hansen, the safe level of atmospheric CO2 concentration to keep below the crucial 2 degrees of warming tipping point is 350 parts per million (ppm). We stand at 400ppm. Scotland's carbon emissions stand at 51 million tonnes. To meet our climate targets, we will need to reduce this to 40 million tonnes by 2020. If 12 billion barrels of North Sea oil were to be burned (the maximum estimate is 24 billion barrels), this would emit 5.2 billion tonnes of CO2, dwarfing domestic efforts. There is a perception that the Scottish economy relies heavily on oil, so such concerns create a dilemma. Indeed, this is a reason many people are opposed to Scottish independence. They think we are vulnerable to oil running out, or the vicissitudes in price.

But here is the fact the Yes campaign should be shouting from the rooftops: even if the entirety of North Sea oil is excluded, Scotland's GDP per capita is $34,754. This puts us between Italy and Japan and they seem rich enough to me. Indeed, books such as The Spirit Level demonstrate that, when a country reaches a certain level of GDP (around $25,000 per capita) what matters is not gains in wealth but how equally that wealth is distributed.

Making too much of oil is not only immoral and ecologically dangerous. It is also strategically foolish. I write this as a Yes supporter. Moreover, putting the climate crisis central stage would not be a departure from the direction of the debate; it would bolster the case that independence constitutes an opportunity to break with neo-liberalism. Yet I believe Scottish independence offers the best chance to deal with environmental challenges. The vast bulk of the money needed to develop the renewables industry comes from the private sector. For investment, it needs confidence there is political support for the technology.

Scotland, with its superior climate change legislation, provides a better environment for that investment than remaining with a Westminster where climate change denialism is rife. Indeed, Chancellor George Osborne recently said he does not want Britain to be a world-leader in tackling climate change: "I don't want us to be the only people out there in front of the rest of the world ... we shouldn't be further ahead of our partners in Europe."

Only by putting such concerns at the heart of the debate can the campaign for Scottish independence legitimately claim to be a genuine break with the excesses of free-market capitalism.