Many European cities spend more on heating schools than on education itself, according to the Mayor of Heidelberg, Germany.

He is just of one of thousands of people gathering in Rio de Janeiro, Brazil this week for the UN Conference on Sustainable Development.

Eckart Würzner, along with other Mayors is presenting 30 proposals for the energy transition of cities and towns.

Monica Villela Grayley spoke Mr. Würzner during one of the many side events happening at the conference.

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