November 25, 2014; 5:20 PM ET
Mainly dry and colder air will continue to sweep into Pittsburgh through Wednesday and should work to keep a snowstorm just to the east. more >
The United States and China surprised climate-policy watchers this week by announcing a rare accord to cut carbon pollution.
The long, harsh winter at the start of 2014 led some experts to predict that the cold season's "polar vortex" would turn into a "pollen vortex" during the warmer parts of the year, with a massive pollen eruption and a brutal allergy season.
The annual surge of sneezing, watery eyes and runny noses for allergy sufferers is only poised to get worse as the climate changes, and new research shows that greenhouse gases have a direct effect on aggravating these problems.