Useless? Of course not. Completely negligible? Absolutely, 100%. I'm no climate scientist but voting literally once for the party that believes in climate science probably has about a million x the effect of you not going on vacation.
>Be conscious about what we can do as individuals
All I'm contesting is that the most effective thing we can do is participate and organize in politics.
Not going on vacation and markedly decreasing your quality of life to reduce climate emissions by 1x10^-9999999 percent is naively negligible at best, a propagandized (by an oil company nonetheless) abdication of their larger responsibility to participate in politics causing the actual damage as science denying lunatics fill offices around the nation at worst.