[nonrandomstring]

This story about urban albedo interested me earlier [0].

Painting roofs and roads white, and simply having more green parks instead of paved areas would actually make a difference.

[0] https://news.ycombinator.com/context?id=39356361

[kilotaras]

Urban area is around half percent of earth area (2 mln km2 vs 510).

Improving albedo there may have some local effect, but unlikely to contribute significantly to climate change mitigation.

[phreeza]

Solar irradiation is around 1000 W/m2, and greenhouse gas forcing is about 2.5 W/m2, so it's not that outlandish.