The study is an interesting read, but the article on sputniknews chose the most attention grabbing headline.

From the study "Pornographic videos make up 27% of all online video traffic in the world. [...] close to 0.2% of global emissions". Later it says it's "5% of global GHG [that's green house gas] emissions due to digital technology"

Interestingly this doesn’t consider what effect this might have on population growth, size of which also affects co2 emissions

Food production/ consumption also emit (way more) carbon dioxide. Why is it right to fulfill one kind of desire, and wrong to fulfill another? The fundamental problem is over population. And porn watching is alleviating it.