The Brighter Side Of Air Pollution

[Dead_Parrot]

Last edited Wed Apr 4, 2012, 05:33 PM - Edit history (1)

One of the most persistent myths about human-caused global warming is that it should be driving temperatures steadily upward. The misconception is understandable: we’re steadily adding carbon dioxide and other greenhouse gases to the atmosphere, so it makes sense that the temperature should be going higher every year.

Climate scientists know better, though. All sorts of forces drive global temperatures, including changes in the Sun, changes in ocean currents, volcanic eruptions that block solar heat and cool the planet, and more. In the middle of the last century, for example, soot and other particles spewing from factory smokestacks, collectively known as aerosols — cooled the planet for a couple of decades. In the decades before that, the Sun brightened a bit, making things warm especially fast.

In the first decade of this century, the warming slowed, and nobody’s quite sure why. “The fact is that we can't account for the lack of warming at the moment,” wrote Kevin Trenberth of the National Center for Atmospheric Research in one of the infamously hacked “Climategate” emails, “and it is a travesty that we can't.” He wasn’t lamenting any sort of challenge to the idea of human-triggered climate change, as many skeptics claimed, but only an incomplete knowledge of how climate behaves on short timescales.

The knowledge gap may just have narrowed, however, with the publication of a new study in Nature (one of two we’re reporting on this week, as it happens) that appears to move the explanation for one type of climate variability from the natural to the human camp.

More: http://www.climatecentral.org/news/the-brighter-side-of-air-pollution/
paper (sub): http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10946.html

This was the original coverage I posted, which now requires registration:

Study finds air clean-up link to US hurricanes

Cleaning up air pollution from factories in North America and Europe could have helped to cause more disastrous hurricanes in the US in recent years, new research suggests.

In a study with important implications for the insurance industry, scientists from Britain’s Met Office say they have established a link between pollution wafting across the ocean – and efforts to remove it – and events such as drought in the Sahel region of north Africa and hurricane activity in the US.

Their study focuses on the North Atlantic ocean, where surface temperatures rise and fall by up to one degree Fahrenheit over phases lasting up to several decades.

A warm period increases both hurricane activity in the North Atlantic and rainfall in parts of Africa and elsewhere, while a cold period has the opposite effect.

More: http://www.ft.com/cms/s/0/6c75763c-7e50-11e1-b20a-00144feab49a.html#axzz1r6MABTLS

[longship]

1. Is this related to global dimming?

Sorry, linked article is registration only so I couldn't read it and will not register just to read it.

[Dead_Parrot]

2. That's annoying, it was free to view when I posted...

Dug out another for you

[longship]

3. Thx. Apparently it is.

Particulates moderate the effects of CO2 by blocking solar. This was first found (apparently) just after 9/11 when air traffic was stopped and later verified by climate data from Australia that went back decades. (sorry, no link, but PBS Nova reported this a few years ago.)

Interesting. Glad to see confirmation. Another parameter to add to the climate models.