The Trump administration’s plans to stymie and defund bike lane plans in the US, on the unusual basis that they are DEI tools, will hurt efforts to improve roadway safety, non-motorized transportation advocates say.

The transportation secretary, Sean Duffy, posted on X this month that he had redirected $1.73bn allocated for “Biden-era DEI pet projects” to “America’s actual backbone: ROADS, BRIDGES, AND SHIPPING PORTS”.

Duffy did not explain how the transportation department would determine which bike lanes support diversity, equity and inclusion. The administration also recently removed bike lanes and speed cameras from the Federal Highway Administration’s list of proven safety countermeasures.

As heatwaves intensify across Europe, most cities are reaching for a familiar fix of more air conditioning. But in 1990s Paris, planning began for a different kind of solution: one of the world’s largest district cooling networks.

The system has 120kms (75-miles) of underground pipes distributing chilled water to museums, offices, hospitals, schools and other public buildings including the Louvre, the Grand Palais, and some luxury hotels and office districts. Instead of thousands of individual air-conditioning units, cooling is produced centrally and shared across the city like a utility.

The system circulates cold water through a network of pipes: cold river water from the Seine is pumped through one pipe, which runs right next to a secondary pipe carrying warm water from the city’s buildings. A thin metal wall separates them and a heat exchanger allows the heat from the warm city water to enter the cold Seine water without the fluids ever touching. It is similar to holding a cup of hot tea in a bowl of cold water – the liquids don’t touch, but the tea cools down