A TECHNICAL paper, Secular temperature changes in Hawai‘i, published just last year in Geophysical Research Letters indicates there has been recent warming on the island of Hawaii and this has been most evident at high elevations. Retired economist, Tim Curtin, has reviewed the paper and comes to a different conclusion.
Mr Curtin has also plotted his own chart, see above, drawing on the atmospheric CO2 data recorded at the Mauna Loa Slope Observatory since mid-1958 and the temperatures reported at the same location. Interestingly despite the increasing interest in changes in climate, Mr Curtin comments that since 1992 data collection has been erratic at this key site.
Tim Curtin explains his objections and conclusions:
Data from 5 of the 21 temperature stations used in the paper are from major population centres and/or airports, and only 4 “high altitude stations” were used to represent the 42 percent of Hawaii that is above 900 metres in elevation.
Giambelluca et al use “anomalies” of average temperature from the 1944-1980 mean, which removes Mauna Loa from its data, as temperature records there began only in 1955. Yet Giambelluca et al. confidently produce dramatic statistical trends for high altitude Hawaii (42% of total area) from at most 3 stations for the period from 1919 to 2006.
Mauna Loa is significant as this is the site at which carbon dioxide concentrations are recorded and this site is considered a global reference for carbon dioxide.
The temperature data at Mauna Loa from 1955 do not support the conclusions of the paper, of extreme warming at ‘high altitude Hawaii” to the extent of 0.268 C per decade since 1975. Actually as the graph shows there is a slight declining trend in the annual increases in temperatures at Mauna Loa.
A plot of changes in temperature and carbon dioxide year on year from 1959, as in the chart, shows a steady rise in concentrations of carbon dioxide but no increase in temperature.
I conclude that there is no relationship between carbon dioxide and temperature at a pristine site like that at Mauna Loa. In conclusion the whole theory of ‘radiative forcing’ allegedly arising from increasing concentration of carbon dioxide over time has no validity at pristine locations like Mauna Loa.
Notes and Links
Citation: Giambelluca, T. W., H. F. Diaz, and M. S. A. Luke (2008), Secular temperature changes in Hawai‘i, Geophys. Res. Lett., 35, L12702, doi:10.1029/2008GL034377.
The chart is drawn from temperatures data here: http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?hi6198
Use the scroll bar on the left and scroll down about half way, find the header Temperature (or Precipitation). Under that, find Monthly Temperature (Precipitation) Listing and click on “monthly totals”. This will give you a table of monthly and annual values for that station’s entire period of record.