Space/Science — HabitableZone

Space/Science » in reply to re: "Burden of proof" vs "ruling out"

re: "Burden of proof" vs "ruling out"
ER — (archived)

Astronomy has identified many types of variable star, and there is a great variation in the amount of variation as well as the period. Some of these variations are precise and regular, sinusoidal, in fact. Others are erratic and unpredictable, even intermittent. Some of these variability modes have been precisely traced to known physical processes and are well understood, others are still a mystery.

Unfortunately, our observations of other stars are blurred by distance, and we cannot study the type of minute variation the sun is suspected of in other stars. G-type main sequence stars have always been considered extremely stable, but that assessment would be very premature if applied to the sun's effect on climate, where even a minute variability, in time or flux, would have colossal consequences. Even a short-term, low amplitude variation in the sun might average out to no change at all in the long run. The only way we can resolve this is to study high precision flux numbers over long periods of time. I suspect that data of this quality may only be available for the last few decades, with less precise data only going back for, at most, a century. This may not be enough to say what is going on, one way or another.

My instinct is to say that minute solar variability cannot be ruled out as a cause of global warming (whose existence in itself is not without controversy!) but neither should it be seized upon as a means of dismissing an anthropogenic cause to said warming. In short, we just don't know.

But I agree LJK is the man to find out.

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