Green roofs are good for the city by buffering water, cooling the air, absorbing fine dust and – of course – improving biodiversity. The Amsterdam crowdfunding and crowdsourcing platform Rooftop Revolution launched in 2016 aims to create the newest Dutch natural reserve, right in the middle of Amsterdam. The initiative has realized some 1.300m2 of green roofs in the city so far. With a practical online toolbox the site provides insight in what the options are for individual rooftops, and what costs can be expected. There is also a special incentive for roofs from 200-1.000m2.