[dj_mc_merlin]

I did not suggest companies emit CO2 for lols -- it is quite obvious they are responding in an optimized way (for them) to consumer demands, since that is what a company is.

But the onus to change is on the companies, and since they won't change themselves, it falls on the government. However, taxing the emitter will lead to companies passing on the cost to the consumer, which, while lowering the emissions, would end up locking away a large number of luxuries (air travel, different kinds of food like meat, etc.) from lower-middle class people. It is very easy to say "increase taxes!" when you have enough disposable income to be able to afford these luxuries anyway. I personally do not want to go back a hundred years where meat is rare luxury and the farthest one travels is to the nearest country, once a decade.