Hacker News

When you look at an aerial image of an average North American city or town ..... 80 to 90% of the land area is either concrete or asphalt. It's like living on a hot plate and all it does is collect more heat.

Building anything on land starts directing rain elsewhere, which has implications for downstream flooding and the levels of the natural aquifers people and the environment depend on. Disconnecting your dow spouts if you have them is a great thing to do, since they're usually connected to sewers

In the Netherlands we have the National Championship Tile Flipping. Which is just the same movement to get people to reduce the amount of tiled surface in backyards.