What's the use case for such a header? User agents (browsers) tallying up an estimated C02 emissions for a session? That'd require a lot of buy in from sites a

What's the use case for such a header? User agents (browsers) tallying up an estimated C02 emissions for a session? That'd require a lot of buy in from sites and I don't expect many to adopt this or give out that info. Also, does google want you to use your browser less? Probably not...