You can make this argument more general (and IMO, even more ridiculous):
Fossil fuels are global commodities. Anyone who reduces their oil consumption is reducing demand for those global commodities, which makes them cheaper. Making them cheaper makes renewable energy less competitive, which discourages investment, which means as a society we keep using fossil fuels for longer, which means in the end we produce more carbon.
Ergo, anyone who tries to reduce their fossil fuel consumption by not flying, not driving, or turning off the A/C, is actually more responsible for destroying the planet.
You're making the argument that reducing your demand for something does not reduce the demand for that thing, because demanding less of something makes others demand it more.
Fossil fuels are global commodities. Anyone who reduces their oil consumption is reducing demand for those global commodities, which makes them cheaper. Making them cheaper makes renewable energy less competitive, which discourages investment, which means as a society we keep using fossil fuels for longer, which means in the end we produce more carbon.
Ergo, anyone who tries to reduce their fossil fuel consumption by not flying, not driving, or turning off the A/C, is actually more responsible for destroying the planet.