Limestone decarbonation and fossil-fuel burning during concrete production are responsible for 7.5 per cent of global human-caused carbon dioxide emissions. A new study found recycling used concrete could “lead to zero emissions cement while also reducing the emissions of steel recycling.” As New Atlas reports, “Throwing old concrete into steel-processing furnaces not only purifies iron but produces ‘reactivated cement’ as a byproduct. If done using renewable energy, the process could make for completely carbon-zero cement.” 

Producing steel creates about 10 per cent of global greenhouse gas emissions. Using “an electrochemical process called molten oxide electrolysis (MOE), which eliminates many steps in steelmaking and releases oxygen as its sole byproduct,” MIT spinout Boston Metal is on its way to reducing emissions with a process that “doesn’t require water, hazardous chemicals, or precious-metal catalysts” and can “help mining companies recover high-value metals from their mining waste.”

Sometimes solutions don’t take a great feat of technology — just a schedule! Maritime technology and law consortium Blue Visby is testing a way to reduce shipping emissions by dispensing with the traditional “sail fast, then wait” approach. By reducing shipping speeds and coordinating so cargo ships spend less time in port, the maritime industry can reduce its carbon footprint by about 15 per cent. “It also reduces underwater noise pollution and whale strike risk; it improves the air quality outside ports; it reduces the risk of collisions and anchor loss at busy anchorages, and it reduces hull fouling, which in turn improves vessels’ operational efficiency.” 

As sea levels rise in response to global heating, threatened small island states “have long felt neglected by successive global summits where pledges to cut carbon emissions have fallen far short of the minimum for limiting the worst effects of global warming,” according to Reuters. That may change with a recent International Tribunal for the Law of the Sea ruling that “emissions from fossil fuels and other planet-warming gases that are absorbed by the oceans count as marine pollution.” That means states have a legal obligation to monitor and cut emissions. Although it’s an “advisory opinion,” it will likely set a precedent for other cases.