NOT for nothing is Aberdeen known as the Granite City. Its oil industry is in the throes of three crises, one cyclical, one structural, and one potentially existential. Yet on September 5th, when the industry’s stalwarts gathered for a biennial conference on the future of North Sea oil, they put on a brave face. “I’d be a bit wary of piping the last lament,” says Robin Watson, boss of Wood Group, a big Aberdeen-based oil-services firm. The first, cyclical crisis has been caused by the oil-price crash that started in 2014. Costs for exploration and production that had ballooned when oil was above $100 a barrel became millstones. Profits plunged, forcing firms to slash costs. Jobs in Britain’s maritime oil-and-gas industry have fallen from 460,000 in 2014 to about 300,000. The number of some types of exploration project has fallen to its lowest since 1971. Tax revenues from North Sea oil, which since the 1970s add up to £330bn ($430bn) in today’s prices, have all but dried up.

The structural crisis is one of old age. In its fifth decade, the North Sea basin is now termed “ultra mature” by Wood Mackenzie, an energy consultancy. Others less politely liken it to a maritime used-car lot, with second-hand rigs changing hands at low prices and old bangers being decommissioned or turned into scrap. Simon Flowers of Wood Mackenzie says that by 2022 the money spent on decommissioning will exceed investment in new sources of growth. In May Royal Dutch Shell removed the 24,200-tonne topside of the first platform to go in the Brent field, which was discovered in 1971. Official estimates say the North Sea’s total decommissioning bill may reach £60bn, for which taxpayers are on the hook for about £24bn.

The third, potentially existential crisis relates to the future of oil and gas itself. If oil demand peaks, as some predict it will by 2030, North Sea oil would be unlikely to survive an era of permanently low prices. Unit operating costs to extract oil have halved since 2014, but are still much higher than in parts of the Middle East, the Gulf of Mexico, Africa and even Norway. Though oil and gas will remain vital sources of energy for decades, a reminder of the rise of alternative sources is the proliferation of North Sea wind farms, including one at the nearby Trump International Golf Links, which has irked its owner.

Yet efficiency improvements that are squeezing more oil out of the ground and a flurry of recent deals indicate that there is still hope for the industry, even with oil near $50 a barrel. For the past three years British oil production has bucked a trend, started in 2000, of falling output. A string of new fields commissioned during the boom years until 2014 are coming on stream (see map).