Reuters: ‘s erupting volcano has spewed plenty of ash but far less greenhouse gas than Europe’s grounded aircraft would have generated. Carbon dioxide emissions totaled 150,000 tonnes a day in the early days of the eruption, according to Durham University. That compares with 510,000 tonnes per day emitted when planes are flying as normal over the continent. But experts cautioned it was hard to draw conclusions about the overall impact of pollution because more cars and buses were on the …