That year the world climate started cooling. Last year CO2 fell by 6%, the year before 4.5%. Now man-made Climate Change pundits say, it is NO/NO2 that governs world climates – not CO2. Paris irrelevant nuclear PR.
Main source of NOx, natural lightening. Rain washes NOx out of the air as plant fertilizer. A static 4 parts per billion is left ion the global air: nothing to do with man.