So there seem to be different companies that offer a person to pay a certain amount of money for compensating their C02 emissions (i've seen it offered also when buying airplane tickets). I think often it is related to projects that plant trees or maintain a certain forest area.

But we all know that C02 is only part of the issue, because our actions have way more consequences (water/other material waste, electrical consumption, etc).

Im at the moment starting an organization with some friends, related to education, development of critical reasoning, sustainability. We would like to be as sustainable as possible in our actions, so we were considering that for all and every project we make, we try to calculate the costs and try to have zero or very low ecological footprint.

We will already try from the beginning not to be wasteful (thinking of energy/resource consumptions in our daily works, etc), but we want to go beyond that to really compensate for our projects

So what I would like to know from you guys is:

1- Is anybody aware of tools, websites, formulas, books or guides that can help one to calculate the footprint of one's actions in a broad sense?

2-Do you know of any reliable companies one can pay to compensate C02 emissions?

3- Are there any companies that actually take in account other forms of ecological compensation that are not just related to C02?

4- Do you guys see any potential problems in this line of thinking? Any criticism towards the proposal, or towards "compensations" in general?

Thank you