Last month we saw a San Joaquin Valley December with more violations of the PM 2.5 air quality standard than ever before recorded. Data only goes back to 1999 so there is no way to confirm that air was better or worse in the 1980’s.
There is less open burning now but there is also more ammonia in the air from massive increases in factory dairies since 2000. This extra ammonia could actually be increasing the ammonium nitrate in our air which is the majority of our pm 2.5 problem when looking at the entire region.
Now that January has come to a close we can look at the two coolest months together and compare this year to past winters. December and January are not quite the entire winter but the air board isolated August last year for special recognition in terms of peak ozone levels and any comparison over a month long should be a valid way to look at our progress in eliminating air pollution that is so dangerous to our health.
There is no comparison. This is the worst winter on record. What is really discouraging is going back to 1999 and seeing indications of some minor improvement but since 2004 that improvement seems to have stopped dead in its tracks. The charts below tell the story.