Monday, 9 July 2012

Climate stuff from the week 2-8/7/12

'Scientists identify tropical oceans as 'beating heart' of climate change'
Ocean current patterns periodically propel warm water toward the poles, commonly coinciding with El Nino events, that appear to explain how global temperatures are increasing in jumps.
“Warm tropical waters appear to be acting like a heart, accumulating heat and energy, and then pumping it in bursts that progressively move toward the poles, a process that seems to be accelerating.”
“When you compare the timing of these warm sea surface temperature anomalies with the reductions of polar sea-ice in the Arctic and to the west of the Western Antarctic Peninsula, and the melting of ice shelves in Antarctica and Greenland, they coincide to a strong degree.”

'Pre-industrial emissions still causing temperatures to rise'
Because CO2eq concentrations are what cause climatic changes, and not emissions just in that year, the effect is cumulative, and there is also a lag-time until the full effect is felt.
It has been calculated that between 20 and 40% of China and India's total emissions were done in the pre-industrial era, through nothing more than population growth.
This growth in population went hand-in-hand, as it does toady, with land use changes - logging, land clearing for farming, soil disturbance. Removing biomass itself has a near-immediate emission effect, but ground disturbance has an effect that is still going on today.
The blame for total historical emissions should shift by only a few per cent, however. But the point is made that climate change negation will require population control - the global population is much higher, now, than it was pre-industrially, so any fractional change will have a much larger overall effect.

Urban climatic change will be exacerbated by the heat island effect - adding to rising atmospheric temperatures, growing cities are going to contribute more heat, which has beens shown to have a notable effect on health. Heatwaves, of course, cost many thousands of lives when they hit.

Another study has re-confirmed the four-times-global-average warming rate in the Arctic, caused by atmospheric 'greenhouse' gases, and the decreasing albedo of de-iced seas

Around 17000 years ago, eastern North America was covered in kilometre-thick ice. This was a phase between melting periods, when the ice sheet retreated.
Around 20000 years ago, rising temperatures caused the ice to melt, which poured freshwater into the North Atlantic, braking warm southerly currents, and causing a kind of kick-back, temporarily cooling the American continent again, until the warming effects resumed centre stage, as the primary effect.

Analysis of coral cores covering the last 6000 years, from across the Pacific, have shown a 2500 year period, from 4000 years ago, in which coral system growth seems to have been non-existent.
Anomaly; alternative explanation; or major shift in the Southern Oscillation?

The climatic effect of a 100-nuclear-weapon war - in the example, between India and Pakistan - would be to attenuate light from the sun, due to soot from cities and industrial areas burning.
This would cause a significant drop in agricultural yield, thereby increasing global starvation, with effects lasting a decade, and potentially exacerbating conflicts around the globe.

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