For more than 80 per cent of time, Earth has been an ice-free warm wet greenhouse planet. Ice sheets were rare. We are currently in an ice age that started 34 million years ago. All of the planet’s six ice ages commenced when atmospheric carbon dioxide was higher than now. Previous cyclical climate changes occurred due to orbital changes, variations in solar energy, supernovae, and plate tectonics with sporadic climate changes due to volcanism and impacting.

There have been five major mass extinctions of life and dozens of minor mass extinctions. We are not in a period of mass extinction but a time of species turnover which was normal for most of time. Of all complex life that ever existed, 99.99 per cent is now extinct. Terrestrial vertebrates have short planetary lives and we humans will also become extinct so drink your cellar dry now in case it gets taxed or you face extinction. Bacteria have always been the most dominant life form and largest biomass on Earth. The lungs of the planet are not the Amazon rainforests but ocean slime such as the current algal bloom in South Australia.

If Australia achieves Net Zero by 2050, on the assumption that carbon dioxide drives global warming, then the global temperature will drop by 0.0154°C. There would be a greater temperature change by standing up. Why bother? Why spend a single dollar on a totally pointless emissions reduction of 5, 20, 50, or 80 per cent? Why feed grifters?

Despite literature searches and interrogation of climate scientists, it has never been shown that human emissions of carbon dioxide drive warming. No past climate change was driven by carbon dioxide and, unless the laws of physics and chemistry change because humans happen to exist today, modern climate change is due to the same factors that drove previous climate changes.

If it was shown that human emissions of plant food drive warming, then it would also have to be shown that the natural emissions comprising 97 per cent of the total emissions do not drive global warming. This has not been done. Ice core measurements show that hundreds to thousands of years after natural warming there is an increase in atmospheric carbon dioxide due to degassing from the warmer oceans. Temperature drives carbon dioxide emissions, not the inverse as we are led to believe.

Australia emits one molecule of carbon dioxide for every 6.6 million molecules in the atmosphere. Is anything we do going to make the slightest difference when the US emits 14 times and China 26 times as much carbon dioxide as Australia? During past ice ages, there were a number of times when kilometres of ice were at sea level and at the equator yet there was over 10 per cent carbon dioxide in the atmosphere. Clearly, carbon dioxide did not warm the planet or create a climate catastrophe.

Since the explosion of complex life on Earth 520 million years ago, the atmospheric carbon dioxide has decreased from 0.7 per cent to 0.04 per cent due to sequestration of carbon dioxide in limey rocks, shells and life. If the atmospheric carbon dioxide content of the atmosphere halved, plants and animals would die. We do have a carbon crisis: there is not enough carbon dioxide in the atmosphere. The main greenhouse gas in the atmosphere is water vapour. Carbon dioxide is a minor greenhouse gas, especially at levels above 0.01 per cent.

Over the last 40 years, more than 100 computer models using carbon dioxide as a driver of warming have been created to predict future warming. However, satellite and balloon measurements of temperature over this period show that the models are wrong yet it is these models that are used to create government energy policy and frighten us witless about catastrophic global warming.

Australia emits 20 tonnes of carbon dioxide per person per annum and about 1 tonne per hectare is sequestered as plant food into grasslands, rangelands, forests and crops and into soils and continental shelf waters. More than five times the amount of carbon dioxide emitted is sequestered. This has been confirmed by IBUKA satellite measurements. Australia is already at Net Zero.

The Copernicus-Sentinel SP satellite show that most of the planet’s global methane emissions are from the tundra and tropical forests and the coal fields, termite populations, hydrocarbon and coal basins, and beef growing areas were not identified. Mass balance calculations of carbon dioxide used by grass as plant food and beef, bones, dung, urine, gaseous emissions and leather show that growing beef results in a net removal via sequestration of carbon. If one believes that carbon dioxide drives warming, then eat beef to save the planet!

Hysterical headlines regularly tell us that we have endured the hottest year. Since when? The planet has cooled since the time of Jesus, warmed since the Dark Ages, cooled since Medieval times when it was so warm that the Vikings grew wheat, barley, cattle and sheep on what is now ice-covered Greenland and warmed since the Little Ice Age. Are we surprised that it has warmed since the Little Ice Age to give us the Modern Warming? Why is the Modern Warming claimed to be of human origin yet far greater and longer past warmings were natural?

All households, primary producers, and employers use energy. The greater the GDP, the more energy is consumed. Data centres and AI will increase energy use. To spend trillions of dollars on an energy policy without comprehensive scientific due diligence can only end in increased costs, debt, loss of industries, unemployment, and the destruction of productive farmlands by wind and solar complexes and transmission lines traversing farmlands. Compared to mines and factories, at the end of the operational life there is no requirement for wind and solar complexes to remove infrastructure such as concrete footings or toxic chemicals that permanently remain in soils and waterways. Why can wind complexes destroy habitats and wildlife yet farming and mining can’t? We once had cheap reliable energy, we now have very expensive unreliable energy based on ideology.

We breathe in air with 0.04 per cent carbon dioxide and exhale air with more than 4 per cent carbon dioxide. If one is passionately committed to Net Zero, the solution is simple: drop dead.

This is a summary of the Keynote Address given by Emeritus Professor Ian Plimer at the New Ltd “Bush Summit” in Mount Gambier.