Next time you Sydneysiders go for a walk along Long Reef near Collaroy, check out the rock platform. The platform occurs because sea level has dropped. There is a nick at the base of the cliffs cut by waves when sea level was a couple of metres higher during the Holocene Optimum between four and seven thousand years ago. This was at the peak of our current interglacial. There was no Narrabeen Lagoon then, only a large bay, and the shoreline was the current western edge of the bay. North Head was an island, as were the Insular Peninsula and Barrenjoey.

Old photographs of fishermen’s huts at Collaroy show that there has been no sea-level change for over 100 years. This is confirmed by the 170 years of tide gauge measurements at Fort Denison.

Higher up in the cliffs at Long Reef, there is a distinct red layer some 230 million years old containing rare tiny flecks of green copper minerals. On top of the hills in the hinterland is a pebbly laterite soil that formed in tropical times some 50 million years ago.

There might be no reds under the bed but there are certainly red beds. These are sandstones that formed in desert conditions. How do we know? Dry sand in dunes has an angle of repose of 34º whereas wet sand in lakes, deltas and on the continental shelf has an angle of repose averaging 45º. Under the microscope, individual sand grains from desert sandstones have myriads of minuscule pits from sandblasting.

Desert sands are coloured because of a patina of the red iron oxide haematite on sand grains. This occurs when the atmosphere has a high oxygen content. The atmosphere contains 21 per cent oxygen at present but at times of mass extinction only 5 per cent oxygen and, at times of red bed formation, up to 35 per cent oxygen.

No other planet in our solar system has an oxygen-bearing atmosphere. If there is life on other planets in our solar system, there will be traces of oxygen in their atmospheres. This has not been detected. Measurement of the spectrum of starlight passing through the atmospheres of exoplanets has not detected oxygen. At this stage, evidence for modern life on exoplanets has not been detected. Yet.

Oxygen in our atmosphere only derives from photosynthesis, mainly by green slime and the rest by vegetation. Activists tell us that the Amazon is the lungs of the planet. Not true. It is the green slime in oceans that emits the largest proportion of oxygen. There is no oxygen gas in the core, mantle and crust of the Earth and water vapour, carbon dioxide, nitrogen, helium, hydrogen, methane, rotten egg gas, argon and other rare gases have been degassing into the atmosphere for billions of years. They still do.

Terrestrial plant life on Earth probably arose from green slime-filled freshwater lakes 470 million years ago. The atmosphere then had more than ten times as much carbon dioxide as now. Plant life thrived with all this food, the atmospheric carbon dioxide content rapidly decreased while the atmospheric oxygen content increased giving red beds. There are cycles of atmospheric oxygen which are the inverse of atmospheric carbon dioxide cycles.

In the Devonian (between 416 and 360 million years ago), there were raging global wildfires assisted by a high atmospheric oxygen content of around 35 per cent. This led to increased denudation and erosion. Some lake sediments contain pieces of charcoal from these massive wildfires that were far greater than anything experienced by humans. Modern catastrophic wildfires are small and certainly not unprecedented. In some places, Devonian red beds contain mudstones with fish fossils associated with terrestrial plants showing that there were desert sands with ephemeral lakes.

We breathe in 21 per cent oxygen and exhale 16 per cent oxygen. Oxygen keeps the brain functioning. We breathe in 0.04 per cent carbon dioxide and exhale 100 times this amount because we metabolise carbon-based food into body growth and waste, some of which is carbon dioxide. While sleeping we lose weight because we exhale about 0.2 kg of carbon dioxide. If you want to lose a couple of kilos, get sent to bed without dinner.

A modern setting for red beds is the Persian Gulf. The shallow warm waters are teeming with life and have black muds. The tidal flats (sabkhas) have limey and salty muds and the hinterland contains red dune sands. When sea level rises, the sabkha is pushed inland and deposited on top of the dune sands as dolomite and salt. Black muds are then deposited on top of the sabkha.

Because copper is very sensitive to the amount of oxygen in the air, sediment-hosted copper mineral deposits over time are a window into how the Earth’s atmospheric oxygen content has fluctuated over time. When oxygen is high, copper becomes soluble in water and when it is low, the copper is insoluble and precipitates as copper minerals. Red beds and copper minerals in sediments tell us about the past climate, sea levels and oxygen cycles that occurred after an explosion of cyanobacteria and after plants colonised landmasses. By contrast, lead-zinc mineral deposits such as Mount Isa in Queensland and Macarthur River in the Northern Territory formed in muds when the atmospheric oxygen content was very low.

As soon as the Earth’s atmosphere started to become oxygenated, red beds became common. In Africa six to eight hundred million years ago, metals were flushed many times from the copper-bearing basement and rose through a pile of red beds, sabkha dolomites and black shales deposited as sea level was rising. Soluble copper (plus small amounts of cobalt, nickel and uranium) was immobilised when it met the black shales and the very large rich copper deposits of the Central African Copper Belt were deposited.

The Permian Zechstein Basin (270 to 250 million years old) of the UK, North Sea, Germany and Poland contains red beds (rote Fäule), limestones and salt deposits that were a sabkha and overlying black shales deposited during a marine transgression from rising sea level. Many buildings in Europe used local rote Fäule because of its ease of shaping, strength and resistance to weathering. In northern England, France, Germany, Poland and Ukraine salt is mined from the Zechstein Basin. Huge copper deposits of eastern Germany and South West Poland were deposited by copper-rich fluids that dumped copper (and traces of precious metals) in rote Fäule, limestone and especially in black shale.

In the Cretaceous (145 to 66 million years ago), the appearance of marine red beds in the oceans followed by marine black shales shows how the ocean changed from oxygen-rich to oxygen-poor. Life struggled and died in oxygen-poor water.

If Melburnians escape southwards from the grips of the Sad Socialist City, they will see 128,000 to 116,000-year-old beaches seven metres above modern beaches showing that the previous interglacial was warmer than now. During this time, airports at Adelaide, Hobart, Avalon, Sydney, Newcastle, Port Macquarie, Coffs Harbour, Coolangatta, Brisbane, Maroochydore, Mackay, Townsville and Cairns were under water. The 120-million-year-old basalts on Phillip Island erupted close to the South Pole in a temperate climate associated with the exhalation of large amounts of carbon dioxide.

Now tell me about human-induced climate change again. The evidence of massive natural climate cyclical changes, past atmosphere changes, oxygen and carbon dioxide cycles and sea level rises and falls is written in stone all around us.

Why are the climate catastrophists blind to the bleedin’ obvious? Or do they have another agenda? Words like money, control, authoritarianism and Marxism come to mind.