Please look at NASA’s teaching on the hydroxyl radical and see my comments below:
All scientific knowledge on it points to our reliance on the hydroxyl radical. Ronald Prinn et al write extensively on it here Evidence_for_variability_of_atmospheric_hydroxyl_r (1) and project a 14% reduction in the radical by 2100, but that was done in 2007, before the Arctic permafrost methane problem was identified.
We have to update the importance of the hydroxyl radical as quickly as possible, so that we are ensuring that if we need to, we can restore this mechanism, or, if need be, enhance it so that it reduces the concentration of greenhouse gases in our atmosphere as these gases overwhelm our system. Hydroxyl radicals in some excess cause absolutely no harm, a claim that can rarely be made with natural systems and this sets the cooling -and cleaning opportunity that OH* represents far apart from geoengineering.
We cannot afford to take the hydroxyl radicals, nor the atmosphere’s complete oxygen system for granted, and NASA scientists have not seen the opportunity that lies within this natural group of compounds.