Wires, Financial Times, USA Today etc: Pollution dims skies almost worldwide
Clean-up of coal soot and similar, sulfurous smog-makers in Europe has somewhat brightened skies there in recent decades, but that’s about it on the bright side of air clarity news. Pollution is making days steadily dimmer and murkier in most of the world since the 1970s at least, says a report from researchers at the Univ. of Maryland and Univ. of Texas that is out today in Science Magazine. The news got wide media pickup.
The dimming is rather slight if statistically significant globally at about 0.1 percent per year. It is dramatic in some areas including but not limited to China, India, and nearby regions. The causes are solid and liquid aerosol particles, like a very fine dust or mist. Some varieties are dark enough to absorb sunlight and heat the lower atmosphere, some are brighter and scatter the sun’s energy back into space. All reduce direct as well as indirect sunshine at ground level. The process and the direction of change are no surprise. Some studies conclude that farm productivity in South Asia and China has dropped as crops get less sun. But to have solid, global numbers got this paper prominent play in this world-class journal. The US has dimmed, but barely. One question: how about those reports of some years ago that airplane contrails, spreading into a high thin cirrus, are substantially dimming the sun? Is that still considered the case and how does that phenomenon fit with the aerosols that are this new study’s focus? Further, speculation has been that, overall, such industrial and other human-caused aerosols somewhat blunt global warming and that cleaning them up might provide a little uptick in the temperature. Where does that speculation stand?
Stories:
- AP : Pollution dims skies as well as befouling the air ; Hmm. Watch that synax.
- USA Today - Doyle Rice: Your eyes aren’t deceiving you: Skies are dimmer ;
- Reuters - Will Dunham : Growing pollution leads to “global dimming” ;
- Bloomberg - Ryan Flinn : World’s Skies Dimmed Since 1970s as Pollution Rose, Study Says ;
- Financial Times - Clive Cookson : Science briefing: Darkening skies ; And Europe, he writes, is “the shining exception.” Just a shorty, part of a roundup.
Grist for the Mill: U. Maryland Press Release ;
PIc - source ;