CLEARING UP THE CLIMATE DEBATE: Professor David Karoly goes down the rabbit hole of Bob Carter’s climate theories.

In his book Climate: The Counter-consensus, Bob Carter describes three different realities on climate change; a science reality, a virtual reality and a public reality.

After finishing the book, I realised that there is another reality on climate change, the Carter reality, which seems to be from a different world.

As described in earlier posts in this series, the “science reality” of climate change has involved developing and testing our understanding against all available observations and modelling.

For the science of climate change, as for all other sciences, questioning and scepticism are fundamental aspects. New science is not based on a single scientific publication, but on the accumulation of evidence from many published studies.

This is summarised in a recent report from the Australian Academy of Science, The Science of Climate Change: Questions and Answers. This report was thoroughly reviewed by an independent Oversight Committee, comprised of a number of Fellows of the Academy and a well-known climate change sceptic.

They all approved the whole report, including its key conclusions:

“Global average temperature has increased over the last 100 years.”

“Human activities are increasing greenhouse gas levels in the atmosphere.”

“It is very likely that most of the recent global warming is due to this increase in greenhouse gases.”

“It is very likely there will be significant warming through the 21st century and beyond.”

“Climate change will have significant impacts on our society and environment, both directly and by altering the impacts of other stresses.”

Lets fall through a rabbit hole and enter a different world: the “Carter reality”. In that world, it is OK to select any evidence that supports your ideas and ignore all other evidence.

In that world, geologists like Carter “hold the key to delineating climate history” and “many (though not all) geological scientists see no cause for alarm when modern climate change is compared with the climate history.”

In the real world, this is not true. The Geological Society of Australia, the Geological Society of America, the Geological Society of London and the American Geophysical Union have all recognised the reality of human-caused climate change and called for reductions in greenhouse gas emissions.

In the Carter reality, “there has been no net warming between 1958 and 2005.” Of course, in the real world, there is no basis for this statement from scientific analysis of observational data. The decade of the 2000s was warmer than the 1990s, which was warmer than the 1980s, which was warmer than the 1970s, which was warmer than the 1960s.

So where does Carter’s statement come from? In the Carter reality, he finds a hot year early in the period and a cold year much later, and says there’s been no warming. This would be like saying that winter is not colder than summer because a very hot day in winter might happen to have much the same temperature as a very cold day in summer, ignoring all the other days.

In the Carter reality, “human-caused emissions will have an insignificant impact on the amounts of carbon dioxide in the atmosphere and the ocean” and the observed increases in carbon dioxide are due to emissions from volcanoes or from the oceans.

Of course, this Carter reality has ignored the contrary evidence, such as decreases in oxygen in the atmosphere, and downplayed evidence from changes in carbon isotopes, both associated with fossil fuel burning.

It has also ignored the evidence that carbon dioxide concentrations in the atmosphere are higher than the concentrations in the upper layers of the ocean, so there is a net flow of carbon dioxide from the atmosphere into the ocean.

In the Carter reality, year-to-year climate variations due to El Niño explain the variations in global temperature, including global warming, much better than increases in greenhouse gases. Of course, you have to ignore the fact that you have to remove the long-term warming trend in global temperatures to get this result..

In the Carter reality, the increase in global temperatures due to a doubling of carbon dioxide is low, only about one degree. This is a strange thing to mention as, in that world, there is supposed to be no warming and the increases in greenhouse gases are not due to human activity.

In the real world, the feedbacks in the climate system that were important in amplifying the global warming from the last ice age to the current geological period, the Holocene, are also important in amplifying the warming response for a doubling of carbon dioxide.

This geological evidence, together with evidence from the observed warming over the last century, show that the climate response to a doubling of carbon dioxide will be about three degrees.

But in the Carter reality, there has been “noble cause corruption” to promote alarm about global warming and hide the contrary evidence, by individual scientists, by the CSIRO, by the scientific academies, and by the IPCC.

Of course, this Carter reality ignores the multiple independent inquiries of climate scientists and of the IPCC that have found no evidence of corruption, and only evidence of normal scientific practices.

In the Carter reality, there are many other strange conclusions based on selecting some evidence and ignoring most. The rules of science have been replaced by non-science. In that world, there are large benefits from more carbon dioxide and no adverse impacts, no sea level rise nor increasing acidification of the ocean.

In the Carter reality, it is better to adapt to climate change as it occurs, rather than to act on the best scientific understanding. In the Carter reality, consensus is not needed around scientific understanding, yet he tries to establish that there is a counter-consensus.

If you search the web, you can find several reviews of his book by non-scientists, who also inhabit the strange world of the Carter reality and accept everything he writes. Or you can read a review by a New Zealand scientist who says the book “is a curious read, full of misinformation, straw-man arguments, and poorly-documented assertions.”

If you live in the Carter reality, it is fine to accept non-science.

I hope that most people live in the real world and accept the science reality, not the Carter reality.

This is the twelfth part of our series Clearing up the Climate Debate. To read the other instalments, follow the links below: