Anything that we use now contribute to global warming,
Cell phones,vehicles and even the foods that we eat if it is process food,
Avery company contributes to it.
And anyone is responsible so what could we do about it?
Any device which uses electricity to produce thermal energy for the purpose of heating something is conducive to performing proof-of-work mining 'for free' from an energy perspective. That would include items such as wall heaters and water heaters.
As I mentioned above, it is common-case to sink excess energy into the environment in the form of heat in times of over-supply (like when there is to much sunlight shining on one's solar panels and the grid cannot absorb it.) This would also be a use-case for proof-of-work mining 'for free.'
Of course the hassle and expense of designing, producing, and integrating mining gear means that it may or may not be worth it. That depends more on proof-of-work blockchain developments than on energy systems.
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Note that 'global warming' is a scam. When it was initially conceived of as a scare tactic to help the wealthy obtain more control (see 'Club of Rome') the idea was that the waste heat from industrial processes themselves would kill us all. That didn't wash from the perspective of thermodynamics.
Another thing which didn't pan out was was the Hubbard (of peak oil fame) idea of fossil fuel scarcity.
The CO2 scare kills two birds with one stone and the two above fake problems can be harmonized in the form of 'cap-n-trade', 'carbon credits', etc. This centralizes control of entire world's economies into the hands of a few elite, and creates the 'scarcity' which the technocrats of the 1930's (including chiefly Hubbard himself) needed to justify using energy (denominated in BTU or equiv) as a new monetary system.
