I don’t gaze up to the night skies contemplating an exciting new frontier for humanity. I look beneath my feet. Because over the coming decades, our long-term sustainability will critically depend on how we manage what lies below. For most people – normal people – that subsurface world is an alien, unfamiliar one. But to me, that subterranean realm is the basis of our modern world – the source of the materials that have built our cities and powered our economies.
Yet the late 20th-century ‘age of extraction’ – of oil and gas and minerals and metals – has created a global behemoth of urban growth and human consumption that is crippling our planet’s natural support systems. Humanity faces a 21st-century prognosis of worsening climate and ecological crisis that threatens to take us to environmental limits that our human species has never before encountered. Decades of technological innovation and industrial endeavour – the so-called Great Acceleration – threaten the very operating conditions in which human society has taken root and flourished.
So, the single largest challenge that is out there for society over the next 30 years is, how do we grow a prosperous world whilst taking care of the planet at the same time? Delivering sustainable human progress – long-term wellbeing for all – will depend on the raw materials that lie just beneath the skin of our human planet. Those materials include metals that are critical for the switch from combustion to electric engine, and the decarbonisation of power generation away from fossil fuels towards renewable energy technologies. But whilst the heat, light and motion of the sun and wind are renewable, the turbines, solar panels and batteries to extract that energy are not. There’s nothing renewable about them. We mine them, we manufacture them, and when they wear out we dispose of them. Our glorious green future obscures an unpalatable reality: a future with a lot less carbon in it will have a lot more mining in it.
But the really vital resource of the 21st Century will be water. Fresh water to provide for the planet’s swelling human population and the vast agricultural hinterland that feeds it. Surface sources are dwindling but vast volumes exist as groundwater in the depths. We know how to find it and extract it because it’s broadly the same technology used in oil and gas exploration. And that water can also bring heat. Geothermal waters can be exploited not only where active volcanoes drive superheated groundwaters but also in regions of ancient hot rocks, such as southwest England. Here, drilling several kilometres down, deep geothermal waters have the potential to deliver electricity and heat in ways that greatly reduce the carbon footprint of our energy demands.
And so, for me, the challenge ahead is not a technical one. We have the technologies to hand to do the job. Instead, it is a moral and ethical challenge. It’s about how we choose to exploit ‘the land below ground’ to deliver human wellbeing without compromising planetary wellbeing. Our exploitation of the oceans and the air have come at a huge human cost, so exploiting the global resource base of that other ‘hidden’ commons – the geological subsurface – will be the next, and perhaps ultimate frontier.