Climate Change and Energy

How the IPCC Buries Evidence of the Sun’s Climate Influence

Written by
7 October 2021

The latest IPCC report conclusively states that global warming can be attributed mainly to human activities, particularly emissions of carbon dioxide from fossil fuels. Contributions to warming in recent times from natural causes, including variations in solar activity, are assumed to be negligible. As far as the IPCC is concerned, regarding attribution, the science is settled and there is a consensus among the scientific community…

In stark contrast, my review of the scientific literature published over several decades by hundreds of scientists leads to the conclusion that the level of certainty put forward by the IPCC is highly questionable.

(extracts from the Introduction and later sections continue below, or download the report here).

The issue of the effect of the sun on the earth’s climate is highly complex and the scientific literature reviewed casts reasonable doubt on statements from the IPCC that there is an overwhelming scientific consensus that warming in recent decades is unequivocally almost entirely associated with human activities. Alternative scientific perspectives that solar activity may indeed play a significant role are essentially ignored. The IPCC makes no effort to make the public and policy makers aware that alternative perspectives on the possible contribution of solar activity to climate change are an important and credible part of the peer-reviewed scientific literature.

Possible reasons for the IPCC taking this position have been presented in a recent review of the science by Connolly et al published earlier this year (prior to the publication of the most recent IPCC report) in Research in Astronomy and Astrophysics. Progress in scientific understanding of complex issues is generally advanced by permitting and indeed encouraging awareness of divergent relevant evidence and interpretations…

In particular, the significant minimum around 1600-1700AD in both figures indicates that the Little Ice Age (LIA) may be a direct consequence of reduced Total Solar Irradiance during that period. It would be expected that solar activity would be a major, or dominant, driver of climate change prior to the industrial era, and improbable that this influence suddenly became negligible at the onset of industrialisation.

Using results from Ljungqvist (blue). Artificial Neural Network output using sine wave set from spectral analysis as input, with data prior to 1880 AD used for training and validation, and after 1880 AD for forecasting (red)

The IPCC Pursuit of Scientific Consensus

The IPCC has long maintained the position that human activities are dominant in causing global warming in recent decades…

There have been many reviews and articles published over the same period that reached the opposite conclusion, providing evidence that much of the global warming since the mid-20th century and earlier could be explained in terms of solar variability.

In their review, Connolly et al, considered possible reasons why the IPCC does not take a more balanced and scientifically sound approach to considering alternative possible causes of global warming. One factor they believe is highly relevant is that a primary goal of the IPCC reports is to “speak with one voice for climate science” projecting the idea that there is a single “scientific consensus”. However, many researchers have noted that this has been achieved by suppressing dissenting views on any issues where there is still scientific disagreement. Consequently, an accurate knowledge of those issues where there is ongoing scientific disagreement is often absent from the IPCC reports. Hulme has commented:

The drive for consensus within the IPCC process, and its subsequent public marketing, has become a source of scientific weakness rather than of scientific strength in the turbulent social discourses on climate change…

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Erratum: In the original version of this post and in the published report the Y-axis of Figure 3 was incorrectly given as ranging between 6 and -6 (rather than 0.6 and -0.6). The correct values were supplied by the author and the error arose during the publishing process. We apologise for the error.

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John Abbot

John Abbot is a Senior Fellow at the Institute of Public Affairs

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