Since people are reading this, let me rant a bit:
One of the things you can do, as an individual, to help your local environment, is grow flowers. Even if you live in an apartment, just a flower pot on a windowsill helps - even tiny urban gardens have an outside impact on pollinators.
If you have a yard, you can replace invasive grasses with native species and nectar-rich flowers. Don't use herbicides or pesticides. Leave leaf litter alone over the winter to provide habitat for insects. Set aside a section to "go wild". Just like with flower pots, leaving even a small section of lawn without chemicals and frequent mowing can have an outsized impact on pollinators and native insects.
Lawns and gardens are a space where individual effort and individual care for the environment really does matter. You might not be able to reverse climate change, but you can make a migratory monarch butterfly's day just a little better.
And tell people! Tell people how you are gardening and how you're managing your lawn, and why. Because the most important thing you can do for the climate is talk about it.
If he's using Roundup, he won't have to worry about the grass anymore either.
They sell products for lawns as well