I haven't been writing any "serious posts" for quite a long time. My garden, growing food and managing my household (while dealing with a few difficult personal issues) have taken my time. That doesn't mean that I haven't been thinking. I try to avoid discussions about CO2 in the atmosphere, climate or renewable energy sources, mainly because I don't agree with many people and it is rather stressful to find myself in arguments.
The measurements of CO at Mauna Loa, even if they are inaccurate as a measure for the whole earth, are the longest consistent estimation that we have. Just how unsafe the levels are now does require some projection, and the "deniers" are happy to say that it's all rather speculative so that we needn't consider it an issue. (Some even think that the added CO2 might help plants grow, despite the fact that there is no indication of a CO2 deficiency for plant growth.) Anyway, it has been suggested that 350ppm would be a safe level to contain any serious consequences. Unfortunately, the Mauna Loa levels are now indicating that we are at 410ppm and rising. This does not seem prudent.
The only solution that ever seems to be discussed is the production of electrical energy by "renewable" means to maintain the current "first world" lifestyle.