Hacker News Reader

sure, but don't we put lawns on roofs in cities to try and cool them down in the summer?

i understand the notion of returning to existing vegetation, but these places are already irreversibly altered by the presence of humans anyway. buildings and parking lots and roads and sidewalks have been built.

it's pretty striking when you see what little soil remains being replaced with rocks.

View on HN

In many places green roofs are primarily about reducing rainwater runoff, which causes pollution. However in hot areas like LA, they also reduce building temperatures which reduces energy consumption. Lawns don't reduce building temperatures.

Rooftop lawns in cities are to offset the increase in heat generated by having the city there. They are an attempt to return the environment to something closer to natural.

And yes, xeriscaping is striking. Absolutely beautiful to see native plants, well adapted to the climate, thriving and taking center stage.

Reply on news.ycombinator.com