A global mayors summit at COP21 climate change conference in Paris saw much exchange of information on how cities are endeavouring to decarbonise their cities.
Paris itself demonstrated how a simple technology using water piped from the Seine is being used to cool apartments near the Champs Elysees and other cities are being persuaded that using water in this way will help reduce use of air conditioning and help urban environments
stay cool as the climate heats.
BBC online reports that London Mayor Boris Johnson said he wanted London to follow suit by cooling buildings using water from the Thames.
“I don’t like to admit it – but the French are ahead of us on this,” he confessed.
The system works by taking water from the river and piping it round people’s homes like ordinary piped water air conditioning. In summer a heat pump is used to make the water even cooler by employing technology similar to a fridge.
The mayors summit brought together half of the 80 mega-city mayors who are working together to tackle climate change.
The chairman of the group, Eduardo Paes, Mayor of Rio, said the mayors represented 600m people and a quarter of the global economy.
“We can be very effective,” he said. “Sometimes governments move slowly – we can often move more quickly.”
Among the initiatives shared at the meeting were Copenhagen’s experience. Their mayor Frank Jensen said 99% of homes in his city were warmed by district heating, in which a network of premises are served by one efficient central heating system. He said this had more than halved carbon emissions since 1995.
Clover Moore, Mayor of Sydney, said the city had saved cash and cut emissions by 40% after she learned about low-energy lighting from the Mayor of Los Angeles.
Karin Wanngård, Mayor of Stockholm said a new city area with 12,000 houses would generate more energy than it uses by 2030.
Boris Johnson said a major preoccupation was to find ways of finding a low-carbon way to provide the heating and cooling from natural gas, which made up nearly 50% of London’s emissions.
In an interview with COSPP in September the Mayor of London’s Decentralised Energy Project Delivery Unit (DEPTU)’s senior manager Peter North acknowledged that while the level of uptake of decentralised energy technology was slow at the moment, the pipeline being built up since the unit’s formation four years ago is starting to bear fruit.