OK, team, you know this concept. Cities are full of dark surfaces that absorb and capture energy from sunlight, creating islands of hot, hot heat. We all get sweaty, we turn up the A/C, that makes the city hotter, everyone suffers. This is why it’s a good idea to paint roofs white. And also why it’s a good idea to paint roads pastel green.

Out in California, Lawrence Berkeley Lab has a little showcase going on that demonstrates this simple idea. There can be temperature differences as big as 40 degrees F between asphalt and “cool pavements,” which come in a variety of light pastels:

Of course, like so many of these innovations, these coatings cost a little bit more than the current alternative. On the positive side, though, roads are, as a rule, owned and managed by local governments, not a whole passel of private owners, as roofs are. If a city’s convinced this is a good idea and it can find the funding, it can just go ahead and make the switch. And then the highways look like Easter eggs! A good idea all around.

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