By Geoff Derrick.
Our Prime Minister Malcolm Turnbull lives on the southern shore of Sydney Harbour, and is in a favoured position to observe the climate moods and weather of the Sydney area in the 21st Century.
However, he should be aware that a considerable database exists that scientifically documents the climate history of Sydney Harbour and adjacent beaches, mainly temperature and sea levels, at least from the arrival of the First Fleet in 1788. When Captain Philip arrived in 1788 and landed at Sydney Cove, he quickly established a weather recording framework to help him better understand what the climate trends might be in this new colony.
Over a three year period from 1788 to 1791, two officers Bradley and Dawes recorded temperatures in the fledgling colony 6 times a day. A log of this data was found in 1977 in a remote corner of the Library of the Royal Society of London, and the data were analysed and plotted by Gergis, Karoly and Allan in 2009. They compared the First Fleet data with BOM data from the Sydney Observatory for the period 1859 to 2014, using monthly averages for Tmaximum and Tminimum. A graph comparing the First Fleet data set 1788-1791 with the BOM data set 1859 to 2014 is shown below, for Tmax.
Remarkably, the First Fleet data (red circles), are almost totally coincident with the later BOM record 1859 to 2014 (green dots); the same result is seen also for average minimum temperatures, and so Malcolm could justifiably claim that in the Sydney area there has been no change in trend of maximum and minimum temperatures over 256 years.
Data from the Fort Denison tide gauge in the harbour also shows an almost stable sea level trend for 129 years from 1886 to present day. In addition, a fisherman’s hut built in 1875 along the high water mark at Long Reef, Collaroy has been photographed in 1907, 1936, 1950 and 2014; remarkably, it exists in precisely the same position now as in 1875, and Malcolm could also justifiably claim that in the Sydney northern beaches there has been no documented sea level rise for about 140 years.
Read the whole story on Sydney’s non-alarmist stable harbour and coastline here: http://carbon-sense.com/wp-content/uploads/2015/11/turnbull-and-sydney-climate.pdf [PDF, 4.4 MB]
Geoff Derrick is a consultant geologist who believes in the integrity of scientific observation, rather than flawed outputs from computer models. Prepared 29 Nov 2015