Re: Introducing a new HTTP response header for Carbon Emissions calculation

> Am 14.04.2023 um 05:43 schrieb Willy Tarreau <>:
> On Thu, Apr 13, 2023 at 11:26:30PM +0000, Bertrand Martin wrote:
>> Possible alternatives:
>> * Carbon-Emissions-Scope-2
>> * CO2-Emissions-Scope-2
>> * CO2-Scope-2
>> * Carbon-Scope-2
>> * Carbon-S2
>> * C02-S2
>> It doesn't seem to me that the proposed "Carbon-Emissions-Scope-2" is too
>> long, but it's just an opinion. Are there any rules or standard on this?
> Quite frankly, seeing that the average response header block size on my
> server is 189 bytes, inflating them by 12.7% *just for a header field name*
> without even counting the size of the value, for the sake of pretending
> to care about energy usage would sound like an oxymoron to me. If I was
> an end user seeing this, I would probably try to develop a browser plugin
> to flag sites doing this as greenwashers.
> That's often the problem: waste a lot of energy to spread a message
> claiming we're careful about it, like cities installing big displays
> in the street, powered night and day showing messages like "do not
> forget to turn off the lights, every effort matters". Please at least
> make sure not to replicate such absurd practises. If you emit something,
> it must cost almost zero to produce (calculation and emission), certainly
> not 12-20% of each response header block!
> Also, indicating power usage would be more realistic and accurate than
> supposed emissions which have no measurable grounds for most operators.
> Use a "uj" header to report micro-joules as an integer for example, then
> in the future we could imagine that a site's certificate will contain
> extra information such as the site's average energy sources distribution
> so that the client can apply a rough estimate if they want to guess how
> much this request might use of each source.

Well said.

I would also ask, before we put efforts into engineering this, how this
header would do good things. Especially with considerations how to treat
the cases where the header lies.

It seems impossible for an individual to assess the trustworthiness of
the information. Maybe their response was a lie, or maybe they had just
a lucky cache hit. Or maybe the cost is exorbitant because it had been
the first cache miss for the day?

You will have people post their OUTRAGEOUSLY high request costs on 
social media, accusing a site owner of destroying the planet. So, site
owners will have incentive to report the header as something like:

  (site co2 footprint / #expected requests per year) = reported value

And the easiest way to get better header values? Have more requests.
I therefore fail to see how this header is productive to the cause.

Kind Regards,


Received on Friday, 14 April 2023 07:08:37 UTC