No, We're not Headed for a Mini-Ice Age

[Godhumor]

http://www.slate.com/blogs/bad_astronomy/2015/07/14/global_cooling_no_were_not_headed_for_a_mini_ice_age.html

Sheesh, the global warming denial industry is cranked—and I do mean cranked—into overdrive. The latest is a rehash of an old claim that we may be headed for a “mini–ice age” due to changes in the Sun’s magnetic activity affecting its output.

Let me be very clear: no. I’ll repeat: NO. The overwhelming majority of scientists do not think this can happen. While changes in the Sun’s activity have a very marginal effect on global warming and/or cooling, human contributions to carbon dioxide in our atmosphere completely overwhelm the Sun’s influence. It’s like tapping on your brakes as your car plunges headlong into a brick wall at 100 kilometers per hour.

This new claim comes from a presentation at conference by Valentina Zharkova, a mathematician and scientist at Northumbria University. To be clear, she’s not predicting a 60 percent drop in the light and heat emitted by the Sun, but a drop in magnetic activity in the Sun. This has only a marginal effect on the Sun’s light/heat output. Also, if you listen to an interview with her on Radio New Zealand, you’ll hear some unusual claims, like the climates on other planets are changing due to the Sun—a red herring when it comes to climate change on Earth. She also admits at the end she doesn’t do atmospheric research, so the claim that lowered magnetic activity of the Sun can cause an ice age here on Earth is in my opinion shaky at best.
----------------------------
From Phil Plait, the Bad Astronomer


It was very disappointing to see this story make the rounds in the media, even into places that should know better (Looking at you iflscience.com). I am sure we will see climate change deniers parroting this for the next 15 years.

[Brother Buzz]

1. Badastronomy.com is the Snopes for everything pertaining to astronomy and space science

Phil Plait's reputation is sterling.

[progressoid]

2. Of course there's still the theory of a thermohaline circulation shutdown triggering a mini ice age.

http://science.nasa.gov/science-news/science-at-nasa/2004/05mar_arctic/

https://en.wikipedia.org/wiki/Shutdown_of_thermohaline_circulation#Bryden_measurements_reported_late_2005

[Xithras]

3. To be fair, there's still a lot of legitimate debate about the Maunder Minimum & the Little Ice Age

Unlike Global Climate Change, the relationship between the Maunder Minimum and the Little Ice Age is something that is still debated vigorously in the climatology community, and it's a debate that really has nothing to do with global warming. We know that the Maunder Minimum, a period of prolonged sunspot minimum activity that lasted from 1645 to 1715, roughly coincided with the Little Ice Age, a period that resulted in crop failures, glacial expansion, and abnormally cold and prolonged winters. Phil Plait, who I have a great deal of respect for, is also incorrect when he posits that the Little Ice Age was a northern hemisphere event. Antarctic ice core data, South American tree ring data, Pacific Island sea level data, and New Zealand moraine studies have all demonstrated that the Little Ice Age was a global weather event. It was certainly more severe in Europe than in the rest of the world, but climatologists suspect that the LIA caused a slowdown of the Gulf Stream that reduced the flow of heat to that particular spot in the world. Without the Gulf Stream, France would have the same winter conditions as Maine.

Whether the Maunder Minimum caused the Little Ice Age is the subject of some debate, and it should be made clear that there is NO CURRENT SCIENTIFIC CONSENSUS on it's cause. The theories as to its cause range from Milankovich Cycles (that it was the start of another ice age, until human activities interrupted it), to variations in solar activity, ocean conveyor slowdowns, volcanic activity, to a random statistical fluke as would be expected from any variable system. The theory that it was caused by volcanic activity is relatively new (2012) and is not accepted by many climatologists because it is based on the assumption that a series of eruptions that occurred during the 1200's caused a global temperature change that lasted for four centuries. Volcanic events ranging from Tambora to Krakatoa to Pinatubo have demonstrated that volcanoes CAN change the global climate, but they have also demonstrated that the effect is nearly immediate and that it generally only lasts for a year or two. The mechanism proposed by the theory, that the eruptions led to increased sea ice in the northern hemisphere which impacted global temperatures and suppressed ocean currents for centuries, remains untested and unproven. More importantly, subsequent major eruptions have offered no real evidence to show that this can happen.

The leading theory, at the moment, is that the LIA was caused by a convergence of factors. The Maunder Minimum lowered solar radiation levels at the same time that atmospheric dust was higher than normal, and an as-yet-unidentified third factor slowed the Gulf Stream. There is no consensus at the moment though, and many scientists still believe that it may have been the Maunder Minimum itself that caused it...or that the Gulf Stream caused it by itself, or that volcanoes caused it by themselves (as I said, there's no consensus).

Climate change deniers may have latched onto Zharkova's claim, but that doesn't invalidate the actual science behind it. Solar scientists have been saying for YEARS that we appear to be heading into a new Maunder Minimum, and even NASA confirmed in 2013 that we appeared to be heading into a "Mini Maunder event". The claim that we're heading into a solar event that hasn't occurred in centuries is neither speculation or denial, and is supported by some of the most respected research scientists on the planet. The fact that this will reduce solar output to our planet is also not really up for debate, because there is a well documented relationship between solar output and atmospheric temperature.

The only real question is whether a real repeat of the Maunder Minimum would have a large impact on our atmosphere. The only CORRECT answer to that question, right now, is "We don't know." Anyone claiming anything else is just GUESSING. Because we're not sure what caused the last LIA, we can't be sure what will trigger the next one. Will it be sufficient to counter the effect of AGW? That depends. If the Maunder Minimum WAS the only cause of the LIA and that event repeats, then it will probably put the brakes on GCC for a few decades and cause some temporary global cooling. And if it wasn't the cause? Then, at best, it might dull its effects slightly for a few years.

However, to claim that it will either cause another mini ice age or do nothing at all, as the two camps in the climate change arguments seem to be doing right now, is simply ignorant. The actual SCIENCE, which is the only thing that really matters in this discussion, says that we have no clue what will happen, but that the answer will PROBABLY be somewhere in the middle. Will it cause an Ice Age? Probably not. Will it slow global heating? Probably, but we don't know how much and it would only be temporary.