[Open letter to Tony Abbott]
Mr Tony Abbott MP
Leader of the Opposition
Dear Mr Abbott,
Although I am travelling in the US at the moment I have become aware of the controversy over your comments at an Adelaide school last week, including the public response by [a] scientist with an alarmist global warming bent.
You might be interested in the graph below. The data are temperatures reconstructed from Greenland ice cores and published in the peer reviewed literature. The data confirm pre-IPCC understanding of the climate history of the Earth: Earth warmed from the last glacial maximum about 15,000 years ago when great ice sheets covered North America and northern Europe and sea level about 130 m lower than today. By 9,000 years ago Earth had warmed to the Holocene maximum when temperatures were warmer than today; the Holocene maximum lasted until about 4,000 years ago and there has been irregular cooling since.
The IPCC alarmist claim that Earth’s temperature has been steady for the last 10,000 years but this view is at odds with historical and archaeological evidence.
- Hannibal took his army and elephants across the Alps about 200BC in winter!
- Julius Caesar, about 50BC conquered Gaul and, after building a bridge across the Rhine River, waged war on the Germanic tribes; he and his army withdrew across the Rhine and dismantled the bridge. The Rhine River acted as a natural barrier for nearly 500 years but as the Roman Empire in Gaul was disintegrating the Vandals crossed the Rhine in the 5th century AD. The vandals did not build bridges but walked across the frozen Rhine River in winter.
- Greenland was settled by Vikings and by the 1100s there were more than 3,000 settlements. As the Little Ice Age advanced so the Greenland settlements were disbanded and the last was known to have perished about 1550AD, a century before the coldest of the Little Ice Age.
- For 300 years Earth has been recovering from the Little Ice Age. Mountain glaciers have retreated and high mountain passes of the Alps have opened. Archaeologists have identified artefacts from various eras corresponding with warming and cooling, and retreat and advance of mountain glaciers.
The arguments of the IPCC alarmists rely on an unchanging temperature record prior to industrialisation (that is, no Greco Roman warm period, no cold of the Dark Ages, no Medieval Warm Period and no Little Ice Age) to support their storyline of anthropogenic global warming. They claim that the warming of the past 100 years is unprecedented and therefore must be due to increasing concentrations of carbon dioxide.
Trust this information is useful to your campaign.