Sunday, 26 August 2012

Climate stuff from the fortnight 13-26/8/12

Warming climate has long been expected to cause an increase in the variability of weather - atmospheric events - and this includes the biggest rain band in the southern hemisphere, which occurs over the Pacific, east of Indonesia.
These bands of weather wiggle around, like vibrating strings, as can be seen from satellite images, and climatic warming is exacerbating these wiggles, resulting in increased variability of rain, as perceived by any fixed, ground-based observer.
This is expected to happen in conjunction with El Nino events. Modelling the changes in weather will be a lot harder than modelling the change in climate, however, because weather is short-change fluctuations.
"During extreme El NiƱo events, such as 1982/83 and 1997/98, the band moved northward by up to 1000 kilometres. The shift brings more severe extremes, including cyclones to regions such as French Polynesia that are not accustomed to such events," said Dr Cai, a scientist at the Wealth from Oceans Flagship.

I'm now pretty sure that the surface melt mentioned in recent weeks, has contributed to some major melting.
'Greenland melting breaks record four weeks before season's end'
"Professor Tedesco noted that these changes jibe with what most of the models predict – the difference is how quickly this seems to be happening."

Going, going... almost gone. Arctic ice is expected to completely clear during summers, by 2030. The last record for low ice was set in 2007. New records will probably be set every few years, until 2030.

"By popular demand, a thread devoted to the continuing decline of Arctic sea ice, and a potential new record minimum this year. As before, the figures are hot-linked and will update day-by-day."

'Changeable climate makes frogs vulnerable to disease'
Frogs exposed to chytrid fungus have worse prospects if they live in climates that change according to a regular pattern, and worst if they live in climates that change according to irregular patterns.
This could be a mechanism contributing to the demise of many frog species, around the world, as the climate warms, and the weather exhibits more and greater extremities.

Sea-level rise on Virginia's coast is expected to be from 2.3 to 5.2 feet (70 to 158 cm ) into the coming century, which will cause Virginia's largest city to shrink by 45000 acres.

'New satellite data on melting of Himalayan glaciers'
Like the melt from Greenland and Antarctica's ice sheets, we know the ice of the Himalayas' glaciers is melting, but we don't know how fast.
"researchers concluded the glaciers were losing around 50 billion tonnes of ice each year, but the same data was interpreted earlier [as] around five billion tonnes."
A whole order of magnitude - those are big error bars!

Extreme metrics -- Hansen et al's data for decadal average global temperatures, which shows a trend toward greater variance in climatic conditions.

'Antarctic Peninsula warming: natural variability or “global warming”?'
It is a real signal.
The trend is strong and unambiguous.
The warming almost certainly caused the ice sheet melt observed over recent decades.
And when considered in conjunction with global analyses, we can say that this is evidence of anthropogenic global warming.

A correction about last week's US-emissions article:
The emissions for the US have merely been exported to other countries - while using more fossil gas themselves, they have exported the coal, meaning no overall decrease in emissions. Thanks, guys!
"Gas is less bad than coal," says Anderson, "but only if you keep the coal in the ground."

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