The International Panel on Climate Change (IPCC) has dominated debate on Global Warming (later Climate Change) since its creation in 1988. Brady’s book Mirrors and Mazes: A Guide Through the Climate Debate shows how they did it, and the ‘mirrors and mazes’ of the title refers to tools used by magicians to trick their audience. I have read many books on climate change, but I found much new material here.
The present is not unprecedented, either in climate or alarm: in the 1970s the worry was the coming Ice Age. The modern panic started with the claim that increasing greenhouse gases would lead to runaway Global Warming. This led to conservation issues like reducing CO2 (or even carbon), reducing use of fossil fuel and subsidising alternative energy. Despite no warming since 1998 the alarmist message is still to curtail global warming by reducing CO2, emphasised by warnings of catastrophe from charismatic prophets. In reality CO2 does not correlate with temperature either on the geological time scale or since the inception of the IPCC. In the ice age that occurred 450 my ago the CO2 level was 10 to 15 time higher than today: the one 350 my ago had CO2 like that of today.
Brady bravely attempts to explain chaos (non-linear) theory. The climate system is so complex it cannot be treated with simple math formulae as in models: different outcomes can result from the same conditions. Even the IPCC admits: “In climate research and modelling, we should recognize that we are dealing with a coupled non-linear chaotic system, and therefore long-term prediction of climate is not possible.” But they persist in using mathematical models!
Climate has numerous cyclic effects. Ice ages coincide with periods when the solar system crossed one of the spiral arms the Milky Way. The Milankovitch cycle results from changes in Earth distance from sun, and wobble and tilt of the Earth. Other cycles are Sunspot cycles, the El Nino-Southern Oscillation and many others. There are three warming periods roughly 1860-1880, 1910-1940 and 1975-1998. All had similar temperature gradients, though different CO2 levels, and only the last is attributed to AGW.
The Holocene Thermal Maximum (8,000 to 4,500 years ago) was warmer than today and sea level was 2 m higher. The Minoan Period, the Roman Period and the Medieval Warm Period were warmer than today, so present day temperatures are NOT unprecedented. To produce his ‘hockey stick’ graph showing temperature rising at an ever-increasing rate, Michael Mann had to remove the Medieval warming period! European glaciers have excellent records of advance (cooling) and retreat (warming). The modern retreat started in the 18th C, before any rise in CO2 levels.
The media usually describes any severe weather event as exceptional or unprecedented, and links it to increasing CO2. But over the past 150 years the CO2 levels increased 40% yet there was no meaningful increase in storm frequency. The increase in human population and infrastructure means that storms today do more damage than in the past. This does not mean there are more storms, and insurance statistics cannot be a proxy for extreme events. Cyclones, droughts and floods show no increase over time.
Sea level as measured by tide gauges shows a rise in the 20th C of about 1.5 mm/y, which is no cause for alarm. There is no solid evidence for acceleration of sea level rise. But governments and consultants still appear to accept the IPCC predictions (properly ‘projections’) including extreme guess of 82 cm by 2100. The National Oceanic and Atmospheric Administration (NOAA, 2016) is now using up to 6.6 feet (2m) of sea level rise everywhere.
Satellite measurement indicate higher sea level rise than tide gauges, but results have been adjusted and the raw data are not made public. Some even use satellite data as a benchmark and adjust the tide gauge data! In Australia the most reliable tide gauge is Fort Denison, but the shorter records of Port Kembla and Jervis Bay shows a sea level rise three times greater.
Rising sea levels impinge on the coast, and so lead to of disputes about coastal management. Local authorities and consultants use IPCC Reports as ’non-controversial’ accessible authority. Engineers tend to use the Bruun ‘Rule’, which is based on forces working at right angles to a straight beach, ignoring real topography and processes such as longshore drift. It is virtually useless but gives neat numbers, such as “one metre of sea level rise causes 100 m of coastal retreat”.
Sea ice comes from frozen sea water and floats, so by Archimedes Principle it does not affect sea level. In the Arctic Ocean there is no land mass, so there is only sea ice. Available maps show a warm Arctic period from 1920-1930s; cooling from 1938 onwards. Satellites show a dramatic decrease in ice from 2000 to 2012.
Mapping Antarctic sea ice was difficult until satellite surveys in the 1970s. Since then it has steadily increased, contrary to climatic model predictions. The Arctic and Antarctic show opposite trends, so they cannot both be due to increasing CO2.
Are the icecaps of Greenland and Antarctic ice sheet growing or shrinking. Zwally et al. (2015) reported that the East Antarctic ice sheet is growing and more than compensating from loss by coastal glaciers. Between 2003 and 2008 it gained 82 billion tonnes of ice per year. An ice core from West Antarctica shows the area had warmed since the 1950s but larger warming trends occurred in the 18th and 19th centuries, and the stronger warming occurred before any rise in carbon dioxide levels.
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