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Scripps Research Shows Sun Could Dim By Mid-Century

Magnetic loops gyrate above the sun, March 23-24, 2017.
NASA/GSFC/Solar Dynamics Observatory
Magnetic loops gyrate above the sun, March 23-24, 2017.
Scripps Research Shows Sun Could Dim By Mid-Century
Scripps Research Shows Sun Could Dim By Mid-Century GUEST: Dan Lubin, research physicist, Scripps Institution of Oceanography

>>> Scientists expect the sun to answer -- enter a grand event in the middle of the century. It is an event where less ultraviolet radiation makes it to the surface of the earth. That is great. We might say, finally a way out of global warming and climate change. Not so fast. Researchers at Scripps have created for the first time an estimate. They say it may slow down global warming but will not stop it. It may even make it worse in some locations. Joining me is Dr. Dan Lubin, a research physicists with Scripps institution of of not pursue be in San Diego. How serious can a grand minimum be? Do we know what effects it has produced in the past? >> We had a good idea in the middle of the 17th century where the sun showed you are if any sunspots and at that time in Europe the climate was significantly colder. The Thames River closed over -- first over. The Baltics see froze over. These were major climate changes in northern Europe. We believe the sun might have a good chance of going into a similar grand minimum later the century. >> What causes radiation to fluctuate? >> It is not very dramatic. When the grand minimum events happen, the total solar radiance decreases by only 2/10 of 1%. The ultraviolet decreases depending. The effects on the climate system have regional implications, not necessarily global. This is primarily in Europe. >> You your paper try to figure out how severe the next minimum could be, what did you find? >> The issue is in trying to understand past climate changes in the context of global warming from fossil fuel admission. We do not know how dim the sun became. Our study was the first time we looked at nearby stars that were similar to the sun using some early space telescope data from the international ultraviolet Explorer. We were able to detect some of the stars being in a grand minimum state and compared them to other stores that were more normal like our son is. We made a quantitative estimate of how dim the sun may have been during the grand minimum. >> The minimum you are talking about is when the Thames falls over. Do you expect the Thames to freeze over again? Is that the kind of effect we can see? >> We could see large effects. It is regional. Europe is strongly affected by these solar Deming's. One thing we could see, in addition to Europe cooling, we know that Greenland warmed correspondingly. We believe that could happen again. The earth's temperature is steadily rising. The Greenland woman could be worse. One of the effects of climate change that we are worried about is the sea level rise during to the melting. Greenland is the largest contributor to sea level rise. It makes your colder but if it also makes Greenland, we could see greater melting of the Greenland ice sheet. >> If indeed the minimum comes up, if it does lower temperatures a bit in some areas, we are also contending with rising temperatures because of global warming, could it even out in some places and give us a breather to figure out where we are going? >> The best simulations have projected a small temperature decrease globally to a fraction of a degree due to a grand minimum. This will not get us out of the problem of century scale climate warming. The bigger effect of the minimum will be to shift weather patterns in ways that are unexpected and that we do not necessarily want. >> Are you talking about the fact that Greenland and other places in the Arctic Circle could get warmer, speeding up melting and speeding up sea level rise? >> That is right. >> What can we do with this new data? Is there anything we can do to stop or mitigate the changes in the sun? >> Nothing. There is nothing we can do. Even the fossil fuels we put in the atmosphere already, we have to wait for them to settle out. We are committed to a certain level of climate change that we have to adapt to. There is nothing we can do about the sun. We have to learn what is going to happen is best we can and get used to it. >> What are the best predictions on when this might happen? >> Pointing to a decade is a little difficult. It could happen as early as 2030 it could be later in the century. The current scientific issue with the solar physics is how rapidly the sun would descend into a minimum. Right now the estimates range from to soldier -- solar cycles to 5 solar cycles. We do know the past two solar cycles have a pattern that resembles the step down. >> What does this research -- how does this inform climate science? >> It is important to keep in mind what is going on with the sun. The sun and the earth's lower atmosphere are 2 major drivers in the balance of energy that governs our climate. The focus has been on the greenhouse effect, fossil fuel emissions and its changes on climate but less research has been focused on the sun. We know that for the past 100 years the sun has been bright and consistent and cycling regularly. It is not the cause of the climate change we have seen so far. That does not mean we should go neglected. We should pay attention to what is going on with the sun. A monitor minimum will not get us out of the global warming that we are committed to and will continue to happen but we need to pay attention to the sun because it might surprise us. >> I have been speaking with Dan Lubin at Scripps institution of oceanography. Thank you very much. >> Thank you.

Scientists at Scripps Institution of Oceanography expect the sun to emit less radiation sometime in the middle of this century, which could cause global temperatures to cool slightly.

Scripps researchers estimate the sun could give off about 7 percent less ultraviolet radiation in the next 20 to 50 years. The event is known as a “grand minimum,” something that has only happened 27 times in the past 11,000 years. The last time one of these grand minimums was this severe was in the 17th Century, when the Baltic Sea froze over and allowed the Swedish army to march over the ice and invade Denmark.

But while temperatures may dip overall, the effect will be especially concentrated in Europe, according to Scripps research physicist Dan Lubin.


“Europe becomes colder but southern Greenland and Alaska become warmer,” he said. “We’re already concerned about Greenland warming, the largest contributor to sea level rise. So this could make things worse.”

Lubin joins KPBS Midday Edition on Tuesday with the latest science on what could happen during a grand minimum.