The sending of one email produces ~0.000001 tons of CO2 equivalent, which adds up quickly! Take the UK for example, if every email user in the country were to send one less email per day, that would reduce carbon emissions by 16,433 tons, or the equivalent of ~81,000 flights from London to Madrid. – WTF Fun Facts
Source: https://www.statista.com/chart/20189/the-carbon-footprint-of-thank-you-emails
