Anyone who saw the lunar eclipse last month likely noted that it was relatively bright, with the darkened moon illuminated by ghostly red light. Now that same light is leading some scientists to questions about recent climate change data, according to New Scientist.
A relatively bright eclipse means that the Earth's atmosphere is comparatively free of volcanic dust, and that relatively large amounts of sunlight are being refracted through the Earth's atmosphere. Last week's was rated a 3 on a scale of 0 to 4, meaning that it was very bright indeed. Nor is this the first time – for the last dozen years, eclipses have been relatively luminous, as a result of few dust-spewing eruptions.
Scientists at the University of Colorado, Boulder are drawing some controversial conclusions from those bright lunar surfaces, however.
They say that the lack of observed dust in the atmosphere over the past
12 years could be responsible for as much as a .1 to .2 degree Celsius rise (about .18 to .36 degrees Fahrenheit) in the average temperature on Earth since the 1960s. That certainly wouldn't account for the entire range of observed temperature shifts (the average temperature in that time has risen by about .6 Celsius, or 1.08 Fahrenheit degrees) –
but if true, it could complicate global climate change analyses.
Other scientists say this idea doesn't hold water. New Scientists quotes one of the scientists on the UN-affiliated Intergovernmental
Panel on Climate Change (IPCC) as saying that their recent report, which attributed virtually all recent warming to man made greenhouse gases, had taken the issue of volcanic dust into account.
In fact, the IPCC scientists said, haze levels have been slightly higher over the past 40 years compared to the previous 20 years, so the overall volcano-related temperature trend should have been towards cooling.
There's almost no question that this is going to stir up the climate-change deniers. So, before people get too excited, and claim that all this global warming is happening because we're just going through a period of low volcanic activity – read the IPCC reports. And all the other very good science on the subject.
The Colorado data is interesting, and a welcome contribution to the debate, but in no way reverses the overwhelming body of scientific opinion that that says we're in serious trouble if we don't do something about our greenhouse gas output.
Lunar eclipse may shed light on climate change [New Scientist]
(Image: February's lunar eclipse, as viewed from European Space
Astronomy Centre (ESAC) in Spain. Credits: Manuel Castillo)
