Bitcoin and carbon footprint

To put this into perspective, one Bitcoin transaction is the “equivalent to the carbon footprint of 735,121 Visa transactions or 55,280 hours of watching YouTube,” 
Then there is Tesla — a company whose entire premise is to help reduce climate change through lower carbon emissions — which has invested more than $1.5 billion of its balance sheet in Bitcoin. How would its Bitcoin holdings affect its sustainability score?

New York Times

Does it really work?
They say you grow hair.
Are there any side-effects?