Why A Warming Climate Is Making This Spring So Cold (… and Last Spring So Warm)

Melting sea ice might not seem important to those of us living in the middle of a continent.  It is.

Weather and climate have always been complicated and difficult to understand, so it’s no wonder that climate change is a topic that confuses most of us.  The fact that most climate change discourse is more political than scientific these days makes things worse.  It’s hard to have reasonable discussions because most people’s opinions tend to be linked to whichever loud voices they listen to, and few of us understand climate science well enough to draw our own independent conclusions.

The poor groundhog has been a popular scapegoat for this year's cold spring temperatures.  In reality, both this year's cold spring and last year's warm spring are much more strongly tied to global warming and melting arctic ice.

The poor groundhog has been a popular scapegoat for this year’s cold spring temperatures. In reality, both this year’s cold spring and last year’s warm spring are much more strongly tied to global warming and melting arctic ice.

I’m certainly not going to wade into the politics of climate change, and I’m not qualified to get very far into climate science.  However, I did read something recently that clarified some things for me, so I’m hoping it will help you as well.  Thanks to Joel Jorgensen for passing along the article that spawned this post.

One of the most difficult things to understand about global warming is that it can make local temperatures get colder as well as warmer.  Here in Nebraska, we’re experiencing a very cold spring – if you can call it spring – this year, but had a very warm spring in 2012.  How, you might ask, is it possible that both the warm spring of 2012 and the cold spring of 2013 are a result of global warming?

Last year at this time, pussytoes was starting to bloom in our Platte River Prairies.  This year, there's no indication that they're anywhere close to that stage.

Last year at this time, pussytoes was starting to bloom in our Platte River Prairies. This year, there’s no indication that they’re anywhere close to that stage.

Scientists have long suggested that more extreme weather patterns (including warm and cold, wet and dry) are a consequence of global warming, but I’ve never had more than a vague understanding of why.  Apparently climate scientists are still figuring it out too, but new research published by Jennifer Francis and Stephen Vavrus in Geophysical Research Letters seems to help.  After reading a summary of the work in the Omaha World Herald and stumbling through the actual scientific journal article, here is my best shot at explaining the results.

First two pieces of background information you need to understand.  This is based on my own rudimentary understanding of this topic, so please take it as such.

1.  The warming of the Arctic and the subsequent loss of sea ice is reducing the contrast in temperature between the cold Arctic region and the warmer center of the globe.

2. The contrast between warm and cold areas of the globe is a major driver of weather patterns because it creates an imbalance in atmospheric pressure.  The jet stream is the major current of air that tends to run along the boundary between those cold and warm areas (there is actually more than one jet stream, but let’s not get into that). When the jet stream is strong, it moves strongly in a relatively straight west to east direction.  However, when it is weak, it makes large north-south loops as it ambles slowly to the east.

Ok, armed with that background knowledge, here’s what’s happening with global warming.  Arctic air to the north of us is less cold than it used to be, so there is less contrast between that air and the warm air to our south.  That weakens the jet stream, causing it to make large loops as it moves from west to east.  Equally importantly, those loops tend to stay in the same place for a long time.

When Nebraska is inside a southward loop of the jet stream, the jet stream’s current allows lots of cold arctic air to come down from the north.  That’s what is making our 2013 spring so cold.  The opposite is true when we’re inside a northward loop – our weather is dominated by warm air coming up from the south, creating a weather pattern such as the one we saw in 2012.  Because a weak jet stream causes those loops to not only be greater in size, but also to stick around longer weather patterns persist for longer periods than they otherwise would.  If the weather extra warm for a long time, we tend to have drought, but extended weather periods can just as easily lead to flooding, extended cold temperatures, etc. – depending upon whether we’re north or south of the jet stream current.

When we are inside a southward loop of the jet stream (top picture) cold air from the north dominates our weather.  When we are inside a northward loop of the jet stream, warm air moves in from the south.

When we are inside a southward loop of the jet stream (top picture) cold air from the north dominates our weather. When we are inside a northward loop of the jet stream (bottom picture) warm air moves in from the south.

Of course, there is much more to weather and climate than just jet stream loops, so a slower, more wandering jet stream is only part of the story.  In addition, understanding why we’re getting more extreme and extended weather patterns doesn’t change the situation – it just explains it.  I’ve written in the past about some climate change adaptation strategies for those interested in prairie management, restoration, and conservation.  A big part of our responsibility is to make prairies as ecologically resilient as possible.  

Since creating and sustaining resilience in prairies is largely dependent upon factors we’ve been working on for a long time anyway – species diversity, habitat size and redundancy, etc. – not much changes when we add climate change into the mix, except perhaps that we should feel a little more urgency.

Again, I’m no climate scientist, so I’m trying to explain things I barely understand myself.  Please correct me if I’ve mis-stated something or explained things poorly.

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About Chris Helzer

Chris Helzer is an ecologist and Eastern Nebraska Program Director for The Nature Conservancy. He supervises the management and restoration of approximately 4,000 acres of land in central and eastern Nebraska - primarily along the central Platte River. Chris is also the author of "The Ecology and Management of Prairies in the Central United States", published by the University of Iowa Press.
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22 Responses to Why A Warming Climate Is Making This Spring So Cold (… and Last Spring So Warm)

  1. Tim Upham says:

    It is climatic change, the warming of the Arctic is pushing the cooler temperatures and precipitation down into the temperate zone. Also, within the Arctic, ice pack is decreasing, but precipitation is increasing. So ice dependent mammals are being impacted, i.e., polar bears, walruses, ringed seals, and ribbon seals. But caribou cannot calf on the plains anymore, because of the heavier snowfall. So they must go up into the mountains. Up into the mountains, the calves are frequent prey for grizzly bears. On the plains, the chief predator is the wolf, and they can see wolf packs to run away from them. So temperate zones are getting the Arctic temperatures in North America, Europe, and Asia. That is the reason why it is called climatic change.

  2. Matt says:

    Thanks for sharing this, I’ve never seen this phenomena described. In general I think the early ‘global warming’ catch phrase has hindered the public’s understanding of the topic. We’re now learning what you describe-it’s more likely we are going to see greater variability which is much more challenging than just a simple mean temperature increase. Also, this variability’s most obvious manifestation is through water. In the past five years where I am in Iowa, we’ve experienced the worst drought and the worst (and 10th worst) flood on record! How do we plan around that!? Coupled with dramatically altered land use, our society is beginning to come to terms with the costs of climate change.

    • ” … I think the early ‘global warming’ catch phrase has hindered the public’s understanding of the topic. … ”

      And when “global cooling” was all the rage back in the mid- late- ’70s, you could have made the identical statement, with the exception of swapping ‘warming’ for ‘cooling’.

      • Cody says:

        A couple of years ago, I attended a conference and one of the keynote speakers was a climate scientist. He also expressed his frustration with the ‘global warming’ label, because it did not accurately reflect the situation and was misleading. His preference was ‘global climate destabilization,’ which of course has not been picked up by the media.

      • Edward J Lagace says:

        I agree with you Russell I have been working to change this interpretation for some time now. People are far more receptive to major swings in our climate then just two years ago. They are becoming far more aware and concerned
        .

  3. Susan Conaty says:

    Thanks Chris! I’m a a Volunteer land steward of The Nash Prairie Preserve in Texas your explanation is just what I needed to understand a little more about the big picture of land management going forward. Also I give a lot of tours of the Nash Prairie and this is the kind of explantion that is most helpful for those who are new to exploring outdoor environments, which there are many. Susan Conaty

  4. Pat Halderman says:

    Great explanation and thank you!

  5. Edward J Lagace says:

    Every day I drive to work I observe the conditions of the Mississippi River Refuge and how the swings in our weather are affecting it. We are in the middle of migration birds are showing up in the rookeries and there is still 24 inches of ice in most of the backwaters here in Winona county and North. Last year we were picking asparagus this year I am still skiing. personally I am flexible and adapt to what it is. It is my hope that we are able to at minimum slow down the process that this civilization has brought about through underestimating the effect it has on the planet we depend on.
    Thank you for a good article.

  6. Steve Clubine says:

    Great job, Chris. With credit to you, I would like to use some, maybe all, of this in my next section in the Missouri Prairie Journal.

  7. Steve Clubine says:

    Thanks, Chris.

  8. Garry winters says:

    Garry Winters
    Thanks for the explanation. I believe climate change is defiantly a more appropriate name for what is happening with our weather. I live Manitoba Canada and still have 2 feet of snow in my front yard. Night time temp close to minus 20 c or 0 f. Weird or What.

  9. Mich Ifella says:

    This whole article is total balogney. There is NO scientific fact backing up your claims. What’s going on here is a moving definition of “Climate Change” such that anything that happens amounts to “Global Warming”. Last year actually was warmer in the Spring due to more solar flare activity, noting solar activity, which IS the best correlation to temperatures changes on Earth, is purposely left out of the discussion because it doesn’t fit the story line of “man made”. The Earth is really in a cooling period, just starting. It’s sad how much is claimed on so little evidence, in articles just like this! SHAME!

  10. Mich Ifella says:

    Dollars to Donuts my comment above never makes it past “moderation”.

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  12. Shocker Larry says:

    How convenient. No matter the weather cold, hot, warm, cool, wet, dry or even normal can be blamed on man-caused global warming. And the warming itself can’t even be detected unless the data is fudged or falsified. Weather is not climate and anthropogenically influenced “climate change” as it is now portrayed, does not exist. Sorry folks.

  13. tseanreno says:

    Mitch, As a true skeptic, I am interested if you have any evidence that that you base your claims (Last year actually was warmer in the Spring due to more solar flare activity, noting solar activity)?
    Thanks Chris for the link, I have seen that info and I enjoyed the article.

    • Tom says:

      I’d also like some science from Mitch. And I wonder if he paid up, or if he’s still waiting for donuts.

  14. Doug says:

    Many thunderstorms are caused by a big contrast between a cold front pushing into a warm air boundary. The higher the contrast and the faster the front, the more severe the storms. This article says 1) that weather patterns stay in place longer and 2) that the temperature contrast is getting smaller.

    If 1 is true, then there should be fewer severe storms. If 2 is true, then the storms should be less severe when they do occur. Yet, on a daily basis, we are told that weather is getting more severe.

    • Chris Helzer says:

      Doug – Far be it for me to try to explain the weather. However, I do think there’s a difference between contrast between fronts and the contrast between artic air and more southern air.

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