Saturday, August 05, 2023

How lawns are making the planet hotter

I have already said my piece on the tyranny of lawns, but here's a rather unexpected (to me, anyway) additional nail in the coffin: lawns are contributing directly to climate change.

What's going on here is the "heat island effect", the way in which different materials absorb, release and reflect heat from the sun, so that cities, with all their concrete, asphalt and relatively sparse tree cover tend to be significantly hotter than surrounding rural areas.

So, a BBC reporter compared his wild unmown garden to his next door neighbour's pristine mown lawn. The mown lawn (what a strange phrase to say!) yielded a surface temperature of almost 9°C - about 16°F - higher than the unmown garden (34.3°C compared to 25.5°C on this particular summer day). That's a pretty dramatic difference.

For good measure, another correspondent compared an unmown lawn with his neighbour's plastic artificial turf. The results were perhaps predictable, but maybe not the scale: the astroturf was 50°F (about 28°C) hotter on a hot day, at 126.5°F compared to 76.5°F!

Maybe more regions need to go the way of California in paying people to rip up their lawns, for the sake of climate adaptation, but also just for our own comfort on this heating planet.

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