Research help CO2 offsetting/compensation programs: How to evaluate them for impact? Alternatives to carbon offsetting? etc.

Hello EA people, 

could you point me in the right direction with my research? In specific, I'm looking for:

1. well-established carbon offsetting programs

2. somewhat riskier projects with high possible up- and down-side

3. valid and useful criteria to evaluate CO2 programs and projects

For instance, I stumbled upon the following: Verra - Standards for a Sustainable Future. How can I evaluate what they do with a reasonable amount of time spent on it (e.g. a couple of hours of research tops) ? 

4. the alternatives to carbon offsetting 

5. how to think about e.g. atmosfair and similar projects

a) Are they effective in what they do, eg. is providing biogas stoves for Nepal families moving the needle on climate change or are those just peanuts (irrespective of the moral dimension of helping underdeveloped countries)? 

b) What are the second-order effects of such initiatives? Psychologically speaking, I can imagine that spending money on eg. atmosfair can lead to an increase in CO2, because of its availability. Instead of deliberating on how to get somewhere without flying, I might default to simply ticking the checkbox at the end of the order and fly anyway.  

5. something that's important within the topic of CO2 compensation which I haven't considered in the above.

I'd be grateful for any tips and resources: reviews, deep dives, relevant Reddit threads, Discord channels, whatever.