[xoxoxoBruce]

Scientists don't "choose" to enter the political arena, they are all in it, as are you and I.
You don't seem to understand that what we call scientists are not gurus on a mountain top, but people who work for someone. As such, like anyone in any occupation, must to be concerned with their future groceries. They are told what to work on, what will be funded, and unfortunately in some cases the results desired.

While Joe Scientist may be pure as the driven snow(although that purity is in question), they are controlled by the people holding the purse strings. People who are always politically aware of the implications. Where the money comes from, and what it must be spent on to insure the reputation of the institution as a worthy recipient for more groceries. These days, the large sums of money trickled down to scientists is controlled by the politics of the benefactors.

When global warming was first investigated, it appeared to be happening, appeared to be influenced by human activities, and scientists seeking funding proposed investigating most every subject which could tie into it. This produced tons of reports on what human activity contributes to global warming. Although the predictions of how bad it would get, and when, were hotly debated.

Now what should we do to mitigate this problem? Ah, the fly in the ointment. Some people/industries will be greatly affected, if not devastated, by these solutions, so will fight tooth and nail. First we change the name to climate change, because global warming and the local weather reports, confuse non-scientists. Then the hundreds of contributing activities had to be pared down to the worst few. Fluorocarbons were tagged and there was not much resistance because it meant profitable solutions were an opportunity. Although methane is worse, they finally decided CO was the one to be named the bad guy, the one to grace their banners and shields as they rode off to battle the skeptics, who are fueled(financed) by those who would bear the brunt of regulations.

So from the scientist worrying about groceries, to the battles in the halls of congress, it's all controlled by politics(money). By nit picking mono vs Di, oxides, you show you completely miss what's going on here in reality, which is politics.