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.