November has gone and summer is supposedly here…

Sirdan and I were lucky to have had a bit of a break when we went touring last Sunday; since then La Nina has been doing her stuff again. However, we almost saw the view from the top of Mount Keira.

I was going to rant about Paul Sheehan’s silly article in the SMH earlier this week about The Greens. Not that I am fully aligned with The Greens, though perhaps more aligned with them than the other two parties. I disagree with them on nuclear energy, for example — there I think they are so sixties.

But I will take issue with one of his alphabetical points:

U: Urban heat islands. Another complication for climate action alarmists is the general rise in temperatures measured in urban areas, reflecting the huge trend in global urbanisation.

Not that chestnut again!

When compiling temperature records, NASA GISS go to great pains to remove any possible influence from Urban Heat Island Effect. They compare urban long term trends to nearby rural trends. They then adjust the urban trend so it matches the rural trend. The process is described in detail on the NASA website (Hansen 2001).

They found in most cases, urban warming was small and fell within uncertainty ranges. Surprisingly, 42% of city trends are cooler relative to their country surroundings as weather stations are often sited in cool islands (eg – a park within the city). The point is they’re aware of UHI and rigorously adjust for it when analysing temperature records.

This confirms a peer review study by the NCDC (Peterson 2003) that did statistical analysis of urban and rural temperature anomalies and concluded “Contrary to generally accepted wisdom, no statistically significant impact of urbanization could be found in annual temperatures… Industrial sections of towns may well be significantly warmer than rural sites, but urban meteorological observations are more likely to be made within park cool islands than industrial regions.”

Another more recent study (Parker 2006) plotted 50 year records of temperatures observed on calm nights, the other on windy nights. He concluded “temperatures over land have risen as much on windy nights as on calm nights, indicating that the observed overall warming is not a consequence of urban development”.

While on the subject of climate, see the latest from The Royal Society.

Now of course if you want CERTAINTY on climate change you’ll have to travel with Dr Who to 2100 and bring back your holiday snaps. If you want reasonable probabilities, which is all you can have, visit reliable sources like The Royal Society and not Climate Candides or axe-grinding interest groups. Anyone sure climate change is not happening and has not been seriously affected by human inputs over the past century is a fool — simple as that.

There are of course many aspects, very many, left to understand. ENSO, including our current La Nina, is one, and the much more recently noted Indian Ocean Dipole is another. Interesting article on that.

November on this blog

2030 views compared with 2026 in October: that’s 68 a day compared with 64 — so not bad. The photoblog halved: 334 compared with 665, but that’s not surprising given I stopped posting there.

2 thoughts on “November has gone and summer is supposedly here…

  1. Like me you may have wondered about the interrelation of ENSO and (anthropogenic) climate change. ENSO is a natural pattern, but clearly if there is an overall increase in temperature over time it will be affected.

    This has not gone without notice. For example see “Living in a variable climate” by Dr Greg McKeon, CRC for Greenhouse Accounting, Queensland Department of Natural Resources and Water, prepared for the 2006 Australian State of the Environment Committee, 2006.

    A major uncertainty in projections of future climate change for Australia has been the direction of future rainfall trends. This uncertainty relates in part to the uncertainty in the response of ENSO to global warming. Whetton and Suppiah (2003, p. 134) commented on likely future changes in ENSO as a result of the enhanced greenhouse effect, based on the review of the Intergovernmental Panel on Climate Change (IPCC 2001). Whetton and Suppiah (2003, p. 134) noted a ‘tendency for most models to show a pattern of change in the average sea surface temperature in the Pacific that was ‘El Niño-like’ (meaning a greater warming of the central and eastern Pacific Ocean). They also found that simulated pressure anomalies near Australia did not follow those that are usually associated with El Niño events (higher pressures over eastern Australia). They concluded, ‘this result strongly suggests that caution should be applied when translating apparent model simulated changes in ENSO to rainfall changes in the Australian region’ (p. 136). Thus simplistic statements that ‘more El Niños under climate change will mean more droughts’ may correctly alert the public to future risks associated with climate change, but may not necessarily be scientifically sound.

    More recent examination of the simulation of ENSO by 20 atmosphere-ocean global climate models has indicated ‘that those models that have the largest ENSO-like climate change also have the poorest simulation of ENSO variability’ (Collins 2005, p. 89). They concluded that ‘the most likely scenario … is for no trend towards either mean El Niño-like or La Niña-like conditions’. They estimated a small chance (16 per cent) of a change to El Niño-like conditions under a climate change regime that resulted from a one per cent increase per year in carbon dioxide. The apparent variation between global climate models in forecasting ENSO behaviour under climate change, and the rapidity of improving understanding that is occurring in climate science, highlights the real difficulty that science and the community are having in understanding the likely mechanisms of future climate change impacts.

  2. Pingback: “Gasland”– a must see « Neil's second decade

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