District heating ranks #27 on Drawdown’s list of climate solutions. By 2050, the technique could eliminate 9.38 gigatons of carbon dioxide at a net cost of US$457.1 billion, and produce $3.54 trillion in savings.

District heating is an efficient energy system that centralizes heating for buildings in a city or neighbourhood by way of a central plant that distributes hot water through an underground network of pipes. This system was first invented by engineer Birdsill Holly in New York and, over time, spread to cities around the world. In Canada, the University of Toronto installed its own district heating system as early as 1911.

Copenhagen has exemplified the use of district heating for its buildings, Drawdown states. The city “meets 98% of heating demand with the world’s largest district system, fueled with waste heat from coal-fired power plants and waste-to-energy plants.”. Copenhagen is expected to replace the coal with bioenergy, and has begun using the waters of Oresund Strait for district cooling.

As Copenhagen’s experience shows, renewable resources can be used to power the distribution network, and waste heat can be reused and repurposed. The use of renewables is not only cleaner but also more cost-effective for municipalities, and its potential to reduce emissions is substantial. “Compared to individual heating and cooling systems, Tokyo’s district system cuts energy use and carbon dioxide emissions in half,” Drawdown notes.

Despite its popularity in Europe, in particular, district heating is not as well known in many other parts of the world, and cost can be a barrier. Municipal politicians and governments can continue to play a critical role in developing, financing, and regulating district heating systems to cut carbon emissions and boost energy efficiency.