There is no let up in new research findings and news reports about the extraordinary behaviour of our sun. Both the UK National Astronomy Meeting and the Swedish Research Council are addressing the sun’s prolonged inactivity that is baffling the astrophysical community. Solar researchers are readily admitting that they do not understand the mechanisms and dynamics that drive solar variability. Nor are they able to predict the timing and the climatic effects of the next solar cycles.
Most climate researchers, in contrast, seem happy to ignore the whole quandary as the sun’s shifting activity and its terrestrial impact do not play any significant role in what is called the ‘climate consensus.’
Solar scientists have been monitoring the sun’s activity for many years in an attempt to establish whether or not its variability is correlated with terrestrial temperature changes. Interestingly, the sun was more active during much of the 20th century than it was for the last 1000 years. Yet, as long as the terrestrial warming trend persisted, this discovery was routinely rejected as wholly insignificant.
Now, however, the sun’s cyclical behaviour has gone into reverse. And, coinciding with its exceptional inactivity, temperatures around the world have actually begun to stall, if not to drop slightly. The arrest of the warming trend of the late 20th century at a time that solar activity is exceptionally low again raises the key question of climate science: has our star perhaps a much more dominant effect on climate change than is generally assumed?
As David Whitehouse makes clear in The Independent today, this question can no longer be dismissed that easily. Neither can it be resolved, on way or another, in the short term. Only time and a determined effort to study and understand the sun’s behaviour will provide answers. There is no doubt, however, that a growing number of scientists are concerned that the next two or three solar cycles may coincide with low solar activity comparable to previous solar minima.
Given the unexpected arrest of the global warming trend and the extraordinary behaviour of our sun, it is prudent to reassess the solar-climate link with extra rigour. The current climate lull provides the scientific community and the world’s decision makers with a respite. They would be well advised to spend more time and money on the study of our variable star whose intrinsic dynamics and climatic effects remain a mystery to this day.