Skyscrapers and bridges, cars and cruise ships, guns and washing machines. All have one thing in common: steel.
As a key input for engineering and construction, it is the world’s most commonly used metal, providing the foundations of the modern industrial economy. Since a method for inexpensively mass producing the iron alloy was developed by English inventor Henry Bessemer in the 1850s, a sprawling industry has grown which today turns over $2.5tn and employs millions of people.
But just as the oil and coal sectors have faced intense pressure in recent years, steel’s role in the climate crisis is now under much closer scrutiny. From the American rustbelt to China’s manufacturing heartlands, the dominant way of smelting iron pumps into the atmosphere huge quantities of carbon dioxide, the main contributor to man-made global warming.
Outside of power generation, the iron and steel sector is the largest industrial producer of the gas. It accounts for 7-9 per cent of all direct fossil fuel emissions, according to the World Steel Association, greater than the total for India.
As climate change rises up the global political agenda and many governments commit to ambitious environmental targets, a race against time is on to develop low-carbon versions of this strong and versatile material.