A first of its kind study in Italy has shown the direct effects of air pollution, and subsequent attempts to reduce it, on the amount of light that reaches soil. Based on daily radiation records of soil from 50 locations around Italy, the authors of the study have shown that after the early 1980s, more solar radiation reached soil on clear days than it had in the previous 30 years of measurement.
The reason for the change is the reduction of aerosols and other pollutants that took place as environmental laws changed. When they enter the atmosphere, air pollutants stagnate there and block the solar radiation coming through the atmosphere.
Between the late 1950s and the early 1980s, there was a significant reduction—or dimming—that was most noticeable on clear days. The increase of air pollution during the 1960s and 1970s is the most obvious culprit here, as smog and other pollutants refracted light and result in less of it reached the ground. That decreased light impacted plant growth and ambient temperatures.
However, following efforts to clean up and reduce air pollution, which were initiated in the early 1980s, there has been a general increase, or brightening, on clear days. Thus, plants received more light than they had in the previous decades.
This study is the first to focus on Italy, but the findings are in line with trends reported from around the world. It gives us yet more proof of the measurable impact green initiatives have had. Looking at this study, for example, shows data-originated proof that the reduction in air pollution has an objective, measurable impact on the lived experience of plants, animals, and microbes on the Earth.