Every Thursday, MPR meteorologist Paul Huttner joins The Daily Circuit to talk about the latest research on our changing climate and the consequences we're seeing here in Minnesota and worldwide.
This week's arctic cold reminds us that climate change does not mean the end of traditional winter weather in Minnesota.
But winters are getting warmer.
Here is an edited transcript of Climate Cast for Thursday, Jan. 24:
Kerri Miller: I've been hearing those loud - it sounds like somebody's hitting the outside of the house. I assume that's the house reacting to super cold temperatures like we haven't had for a long time.
Paul Huttner: That's true. The wood will actually crack as temperatures change. I know at my house some of that noise is ice that builds up around the chimney that tumbles down the roof. So who knows what goes bump in the night on these cold winter nights?
Miller: How long has it been since we've had a prolonged cold snap like this?
Huttner: This is really the coldest week in Minnesota in four years -- the last time we saw this kind of prolonged cold. In fact, we set a record this week for the longest streak without a sub-zero high temperature in the Twin Cities. It's been four years and six days, and that was from January 2009 to this week and that's pretty remarkable.
Miller: You sent me a very interesting chart that shows how long it has been that we've had one of these snaps where it has not gone above zero. What you see, though, if you look at the historical research is that it is becoming rarer and rarer.
Huttner: It is. We've talked about this before. This is not your grandparents' winter anymore that we're seeing in Minnesota. Our children are experiencing very different winters than we did or our parents did 30 or 40 years ago.
Overall, winters have warmed about two to four degrees in the past 30 years or so. One good way to measure it is to look at these number of subzero lows that we're seeing at night. There are distinct trends that are emerging in the past 30 to 40 years toward fewer subzero low temperatures in Minnesota and the Twin Cities.
Quick example: this year we've had five days so far, last year we had three. That's a very low number. If you go back to the 1970s - the whole decade - we had 444 subzero days. During the 1980s we had 280, during the 1990s we had 256; down to 198 in the 2000s. That's a 57% drop in those subzero nights. If you look at that overall the trend lines show we could be down to around 10 on average per winter. We used to average about 30 back in the '70s and we could be maybe closer to zero by 2040. By 2040, in the Twin Cities we could be very close to few or any subzero nights if our current climate trends continue.
Miller: Last week you said that when you look at these warming trends they are most noticeable in nighttime temperatures and winter temperatures.
Huttner: That's exactly right. I thought about this over the week and I talked to a colleague of mine, John Abraham at the University of St. Thomas, to get his perspective on what winters might look like here as we go through future decades. Here's what he had to say about that:
John Abraham (on tape): The winter we saw last year will become more common. You'll notice that precipitation, whether it's snow or rain, happens in heavier downbursts. So we'll get bigger snowfalls or bigger rainfalls even in the dead of winter, but they'll be spaced further apart. And the swings of weather will likely be larger. We'll go from very warm back to cold back to very warm. So we'll expect more fluctuation. This isn't the winter you grew up with. This will be a new generation's winter here in Minnesota.
Miller: To zero in on that, did he say we still may see these very heavy, wet snowfalls but they aren't going to happen as frequently in the cycle? Is that right?
Huttner Exactly right. What we're seeing is a trend toward less snow in winter in Minnesota. Some of the trend lines may be as much as a foot less snow on average in Minnesota by about 2070. That will have a big impact on our rivers and lakes potentially. It's that snow pack that melts off in the spring and raises those lake and river levels. We're sitting in a very precarious spot right now with lake levels well below average as we head into next spring. People aren't going to be able to get boats in the water, things like that, unless we get a whole lot of snow between now and spring, and then above average spring rainfall. That could become more common as we go through time.
Miller: A couple times when we've talked about what the research is telling us and what this is going to mean for us here in Minnesota, this is something that really interests me -- how this changes the way Minnesotans think of ourselves, our own identities. I have to say, as I see this trend line that you and John Abraham are talking about, this is going to change our economy significantly in the decades to come and Minnesota has got to start thinking about that.
Huttner: Absolutely. I don't mean to say that all climate changes are gloom and doom. There are going to be both positive and adverse impacts from the way our climate is changing. There's an old saying, "There's no bad weather, just different kinds of good weather."
Some sectors of our economy will benefit from climate change and some will not. A couple of quick examples -- One of the things that might get affected is maple syrup production. If our spring warms up more quickly like it did last year, that really puts the damper on maple syrup production in the spring. Let's call that the pancake effect. There will also be more unsafe ice. We've had seven cars go through Lake Minnetonka in the last week or so. There will be a greater spread of insects and pests. The positive side will be longer growing seasons, lower heating bills and new varieties of plants. We've already moved into zone 4, and may be headed for zone 5 in Minnesota. That's why we call it climate change. Some good, some not so good, but change is what we're really talking about here.
Miller: President Obama surprised some people on Monday in the inaugural speech by talking about climate change. On Monday, we're going to talk about what the evidence shows us about policies for climate change that scientists actually know are working. We both spotted this article in Forbes about companies that aren't waiting for the government, they're going ahead. One of them is Starbucks. I heard a recent interview with the CEO of Starbucks that basically said we can't wait for Washington to get their act together. We've got to do this because it affects our everyday business.
Huttner: That's remarkable as we bring it to our kitchen table this morning with pancakes and coffee. This concept of climate resilience is a new but growing discipline. These forward-thinking companies are actually already taking tangible, constructive action to anticipate and mitigate, or even profit from, the effects of climate change. Starbucks, Levi Strauss, all have already recognized that business models are changing as the climate changes and they're already adapting to that.
Miller: I want to give our listeners a sense of what a company like Starbucks, how this affects them. They look at how the climate is changing in a place like Costa Rica where they buy a lot of their coffee beans from. They're saying we need to be more supportive of farmers who are raising coffee beans in shaded areas of Costa Rica and who are harvesting water in a smarter way. It gets right down to the farmer in the field in a country far away from Seattle's headquarters. But they have to think about it.
Huttner: They do. It's bottom line tactics for them. They're even constructing shade canopies over some of the coffee plantations there to try to protect from some of the extreme heat, increasing the irrigation systems.
Levi Strauss is working on new techniques to improve cotton with less water. Swiss Re is working with farmers in Ethiopia to build irrigation. This climate resilient concept is to be able to better withstand these changes we're seeing and I find that fascinating. We're seeing that business is already ahead of the curve, at least some businesses.
For those folks that don't think climate change is happening, talk to your insurance company, talk to some of the businesses that you visit every day. They already know it's taking place.
Miller: While you can look back at the history of this, it's still somewhat inexact to say this will happen then and this will happen then. That's what scientists are trying to figure out, what lies ahead.
Huttner: We've got the big picture figured out, in terms of overall the planet warming and we think the rate at which it's warming, even though that seems to be happening a little faster than earlier predictions. What we don't know is regionally what are each of these effects, what areas will get warmer faster, how precipitation trends will change. That's where the real climate science work will be in the next few years.