Bitcoin doesn't amount to much of CO
2 emission since most of the times it is generated through cleaned forms of energy i.e. electricity. In many cases the electricity is generated through renewable sources of energy since the electricity generated through burning coal and fossil fuels is not cost-efficient for mining. Further, the burning of the fossil fuels for generation of electricity is something that the governments need to address before pointing fingers on miners.
The reason for the No. C02 isnt the primary greenhouse gas. its Not even close. H20 is the primary greenhouse gas. it accounts for aprox 60-85% of all greenhouse gases. c02 is under 1% also if you have equal values of CO2 and H2O, h20 is still quite a bit stronger then c02.
H
2O is water, my friend! It is essential for water vapor to be present in the air so that earth has rains. H
2O might be the highest contributor of greenhouse effect, but it is quintessential for the earth to survive. However, water vapor in itself doesn't cause the earth to warm up, rather it is other non-condensable gases that cause it such as CO
2. You can read about this further
here