I was rather disturbed to read the opinion article by Nicola Scafetta and Bruce West, which discussed the global surface temperature anomaly in relation to solar variability. Some important issues regarding their work should prompt readers to question their motivation and whether their conclusions come from an unbiased perspective. I offer those key concerns.
The authors use global temperature data that extend back only to 1890 and cover a short period of time, rather than data from other techniques, such as icecore sampling, that cover a longer time span.
The authors claim that the increase in temperature, and the consequent change in climates, since 1900 is largely due to solar variability. Climates are often defined as average temperatures over 30 years—also a short time scale. However, if we are observing large temperature changes on time scales shorter than 30 years, it is certainly believable that those changes are due to human activity.
More fundamental, though, from a physical viewpoint is that if solar variability were to influence temperatures as much as Scafetta and West claim, that variability should exist over Earth’s entire life span. It should be present in all possible temperature data from prerecorded times. If the Sun were truly having more variability in its output now than it ever has in its past, climate change is not our greatest worry.
More disturbing on a personal, moral level is that the authors are putting forth an argument that attempts to distance us from our responsibility for climate change. Ultimately, that gives readers—including politicians and the general public—justification to continue down the path we started with industrialization around 1900. Many people find that perspective very comforting because it means we don’t have to change our ways of doing things.
The political perspective of Scafetta and West’s opinion is disturbing because the current administration has repeatedly promoted policies that deny human-induced climate change. And the primary funding for the research in this Opinion piece came from the US Army Research Office. Furthermore, the majority of the references Scafetta and West cite are written by one or the other or both of them and have all been published during the current administration.
The authors are entitled to their opinion. Many other scientists, though, and the Intergovernmental Panel on Climate Change hold another opinion: that solar variability has had a negligible effect on climate. Surely, if solar variability were causing such drastic temperature changes, the IPCC would have incorporated it into its models and findings. Instead of trying to blame climate change on solar variability or other galactic events, we should rethink how we live our lives and whether our lifestyles are fundamentally compatible with the needs of other species on Earth. This is the only home we have; we can’t use it up and throw it away in the same manner that we leave our trash at the curbside.