Data sources to monitor GhG emissions

I have been involved in environmental management for a number of years now and I am currently busy with research on projects focused on GhG emission reduction. I would like to make the correlation between if the investments made by investors/funders/donors/producers/emitters and even governments is independent verification/confirmation that the initial GHG emission reductions estimations are being realize and/or on track to being realize according to the project’s forecast models. I am independent but would really like to see some results. I was wondering if you can perhaps point me in the right direction on where to get historical and near real-time credible remote sensing atmospheric data for my research. Also, if you are aware of any land based data providers who are able to provide localized atmospheric data I would truly appreciate it. I hope to hear from you soon.