Like David says the offset projects all seem kind of snake-oil'y, so I looked for something that actually changes something in the world for the better. So far, building green infrastructure seems attractive, but I fear that in the end it just makes energy a little bit cheaper for people, and the real CO2 impact that happens in the transport and agriculture sectors doesn't really get solved.
I also was attracted to planting trees, since there's a very concrete impact there, that can't really be cheated against (unless people burn them down of course). So I started calculating how many trees to plant and it turns out that there's a lot of misleading info.
For example, in ideal conditions a tree might accumulate 20kg of CO2 in 40 years. My car did 16000km at about 1/14, on gasoline so that's 2742kg of CO2. So some website will tell me to plant 140 trees to compensate over 40 years, to compensate what I did in 1 year, assuming all those trees survive.
But they don't, only 55% lives, so I should plant 280 trees to be a bit more sure I really am compensating. And then it'll be compensated in 2060, which is useless because climate is changing now, not in 40 years. So it's better to compensate up front, so say I want to make sure I've made an impact by 2025, I should plant 8 times as many trees, so that's 2240 trees, and that's just assuming they grow linearly, which they probably don't do. And that they are planted in the tropics, which they probably aren't, and even if they were there's a risk they would be burned down for agriculture within the decade anyway.
And that's just me with an under average commute driving a mediocre car.
Does anyone have a better solution for offsetting carbon? Maybe we should pool money together and buy someone that's driving a range rover a tesla..