Calm solar cycle prompts questions about impact on Earth
First seen (by me) on the New Zealand Herald site.
Originally reported by Jean-Louis Santini (AFP)
Washington — The surface of the sun has been surprisingly calm of late — with fewer sunspots than anytime in in the last century — prompting curious scientists to wonder just what it might mean here on Earth.
The question that exercises my mind now is what this means for the global warming debate.
Our sun goes through an eleven year cycle from calm to furious solar flare activity and back to calm again. This has been observed for millennia. Early Chinese astronomers noted it and Galileo was the first to observe it with a telescope. Solar flares, sun spots, or solar storms all describe the ejection of mass and energy from the surface of the sun. On Earth that means an increase ultra-violet and x-ray radiation and sometimes disruptions to our telecommunications. It also means awesome night lighting effects in the polar regions – the aurora Borealis (northern lights) and Australis (southern lights).
Right now “It is the weakest cycle the sun has been in for all the space age, for 50 years,” National Oceanic and Atmospheric Association physicist Doug Biesecker told AFP. 2013 was predicted to be a peak year under the normal cycle.
Santini (AFP) reports that scientists are now watching the sun carefully to see whether this cycle is going to be an aberration — or if this solar calmness is going to stretch through the next cycle as well.
“We won’t know that for another good three or four years,” said Biesecker.
Some researchers speculate this could be the start of a prolonged period of weak solar activity.
The last time that happened, during the so-called “Maunder Minimum” between 1650 and 1715, almost no sunspots were observed. During the same period, temperatures dropped sharply on Earth, sparking what is called the “Little Ice Age” in Europe and North America.
As the sunspot numbers continue to stay low, it’s possible the Earth’s climate is being affected again.
But thanks to global warming, we’re unlikely to see another ice age. “Things have not started to cooling, they just have not risen as quickly,” Biesecker said.
So, the ‘evidence’ of global warming that the sceptics are looking for is being skewed by the sun – for the time being – and we’re not seeing the order of magnitude of temperature increase that some models predicted. There has been an increase in all meaningful measures, just not as great as predicted. The data would be different if the sun had done the usual thing and peaked its energy output around now.
The potential consequences of this make me more than a bit nervous. We can’t control the sun, or even accurately predict it’s behaviour as it now turns out, but we can do something about the greenhouse effect and human contributions to it. The problem is that the sun has literally taken some of the heat out of the debate! But is this just a stay of execution?
The current conservative Australian government is definitely sceptical about human induced climate change. They are rolling back abatement commitments from the previous government and are accused of replacing them with window dressing talkfests as a cover story for a business-as-usual policy direction on carbon emissions. Carbon after all is a very significant revenue earner for Australia – loads of taxes, royalties and ‘donations’ for governments that toe the line here.
The years 2020 and 2050 are often cited landmark years for climate action. These are the deadline years for achieving meaningful change. In solar cycle terms the forthcoming peak years are 2024, 2035 and 2046. The scenarios going forward seem simplistically to be:
- We are seeing the onset of another ‘Maunder Minimum’ cycle – the last one was 65 years or 11 cycles – in which case Earth will receive less solar radiation than expected and the rate of warming will be slower. This could mean a reprieve in terms of climate change impacts, but it could also reduce the perceived imperative for action on the abatement front leading to even greater temperate increase when the cycle returns to ‘normal’. If it is another prolonged weak period it may not last 11 cycles as the previous one did. We can’t know and we shouldn’t count on it!
- This present cycle is a one-off anomaly, meaning that the extreme weather events of the past five or six years have been less severe than they would have been under a ‘normal’ solar cycle. As we are now (2013) at what should be peak solar activity (but is not), the next cycle peaking in 2024 will have a decade more greenhouse gas built up when we are again bombarded with much more energy from the sun. We can’t turn the greenhouse juggernaut around before then, but hopefully will have at least commenced a significant course correction.
For a risk management analysis and a bit of fun, check out how Greg Craven sums up our best bet on this question: How It All Ends.
As ever it makes sense to plan for the worst and hope for the best. Lets keep the pressure on governments everywhere to take action on climate change. One way or another the next decade will be critical. We can’t hope to fix the greenhouse problem before the next expected solar cycle, but that is no reason not to try! One way forward is to start reinventing our economy to end our addiction to fossil fuels and massive resource extraction. Gunter Pauli’s Blue Economy looks like a pretty good road map to me.