Stockholm was one of five European cities awarded money from the New York based foundation, which asked entrants to suggest innovative ideas to improve city life.
The Swedish capital's concept is based on biochar, an organic carbon that can be used as soil conditioner to increase plant and tree growth in the city. The project ”Biochar – for a better city ecosystem” aims to produce biochar from garden waste.
It's not just Bloomberg which has been impressed with the project. In June, it was presented to EU commissioner Corina Cretu during the CITIES Forum 2015 in Brussels and was met with a positive response.
“The Stockholm project was one of ten European projects that had been invited to participate at the conference," said Ola Eriksson, spokesperson for the City Executive Office. “What’s more, the project was one of only three that the commissioner and her colleagues informed themselves specifically about and spoke with in person. ”
Cretu said cities are key to the European Union's future and that "the EU should respond more effectively to the challenges facing our urban areas."
Bloomberg Philanthropies, which was founded by New York’s former mayor Michael R. Bloomberg, said that the Swedish capital, like many global cities, is confronting the effects of climate change.
“Together, the city and its residents will produce biochar. Citizens will bring their green waste to locations across the city for conversion to biochar and, ultimately, redistribution," the organization said in a statement.
The project – a collaboration between the Stockholm Traffic Office, waste company Stockholm Water and power firm Fortum – will run for three years, starting this year. The first step is to create a feasibility study, which will set the framework for where and how Stockholm will produce and use biochar.
The City of Stockholm said that producing biochar could be a way of taking care of garden waste in a more efficient way, compared to today’s method of turning it into woodchips.
Mr Bloomberg said the 2014 Mayors Challenge received great proposals from all over Europe, and that the competition over the past year had been fierce.
“To meet the biggest challenges of the 21st century, city leaders must think creatively and be unafraid to try new things”, he said.