Throwback Thursday: Volcanoes and the little ice age

I've been battling a minor health issue for the past few days, so if you are a regular visitor here, you might have noticed my absence. Or not!

Just to ease back into blogging, here's a placeholder for you from five years ago. This blog started out as mostly my commentary on issues of the day before I folded in the two other blogs I was writing at the time, one about birds and one about gardening, and also decided to include reviews of the books that I read. At that point, it became truly eclectic and I could write about whatever was on my mind on any given day.

One thing that has been on my mind pretty constantly over many years is climate change because it affects all of the things that I care about. I've probably written more words on that subject than I have any other, and I was writing about it five years ago when a new study came out about the effect of erupting volcanoes on the climate.

This is a perilous time in the history of our country and the world, not least of all because the anti-science know-nothings will soon be in charge of all branches of our government, including most likely the court system. This does not bode well in the short term for us, the country, or the larger environment. But in the long term?

In the long term, as someone has wisely said, we'll all be dead, but Earth and physics will continue, because the truth is Nature doesn't give a damn whether we believe in science or not. Science exists. Human-aided climate change exists; the planet is heating up. Your opinion on the subject doesn't matter. Physics is inexorable.

The effect of volcanoes on the climate was an example of that. Their eruptions helped to cause a "little ice age" and drastically affected the course of human history. It was exactly the opposite effect of what is happening now - an anti-greenhouse effect.  It was in the news five years ago and here is what I wrote about it.


January 31, 2012

Volcanoes and the little ice age

Earth's climate and the cycles of warming and cooling that it goes through is one of the more fascinating subjects in earth science. It's a subject that has become fraught with passion in recent years as climatologists have repeatedly tried to warn us that humans are upsetting Earth's cycles and science deniers have done their best to shout them down. But looking back at the historical data is perhaps a little less controversial.

Scientists have recently been doing research on the period from the 1200s to the 1900s, a very cold time in the northern hemisphere that has come to be known as the "little ice age." There have been many theories over the years about what might have caused this prolonged cold period which, in many ways, shaped the culture of Northern Europe, Asia, and North America. At the time it was happening, some people blamed witches. The ignorant always find a scapegoat. But this new study may give a definitive answer to the question of why it happened. The answer, the scientists postulate, is volcanoes.

The researchers have found evidence that there was a 50-year period just before the beginning of the little ice age during which several volcanoes were very active. They repeatedly erupted, shooting ash and debris into the atmosphere where it reflected sunlight back out into space, thus the warming rays of the sun could not reach the planet and Earth cooled off. They believe this caused a chain reaction which redounded for centuries during which the northern hemisphere, in particular, shivered and seldom saw a real summer.

This is just the opposite of what is happening now as humans send pollutants into the atmosphere which create a barrier - a greenhouse cover - that traps heat back on Earth. And so the planet heats up.

Whether heating or cooling, the laws of physics apply. We cannot escape them. The prime causal factor may be volcanoes or human beings or asteroids, but however these factors present themselves, Nature's laws will prevail and Earth will again find an equilibrium. Whether there are any humans who survive to witness it is really irrelevant to Nature.


  1. Sorry to hear you are under the weather (now, in light of this post, that is an interesting expression. I will have to track down its origin.) I myself have been hobbling around with a pulled muscle in my back, though for some reason I can sit in my desk chair without pain. Little blessings. Anyway I like this post. I suppose humans are irrelevant to Nature though I like to think we can contribute to regaining equilibrium, that we are part of Nature. Feel better soon!

    1. I fell better already, thank you. I hope you will soon be free from hobbling - back pain is really the pits!

      We are a part of Nature and we do affect it, although it seems most often for the worse. One hopes that at some point the human race might wise up and start cooperating with Earth's systems instead of working against them. One hopes, but one is not sanguine.

  2. I'm glad you are back and in full force! Very timely this piece on weather related climate change.

    1. Unfortunately, it continues to be timely year after year. The lack of progress on the issue is truly appalling.


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