What is Climate Change

What is Climate Change

Part of Ep. 2104 Climate Change for Gardeners

What will thrive in tomorrow's gardens? University of Wisconsin-Madison climatologist Michael Notaro defines climate change and how it will likely affect gardening in Wisconsin.

Premiere date: May 22, 2013

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley Ryan:

We are in Longenecker Gardens at UW-Madison Arboretum to talk about climate change something that affects all of us. I am with Michael Notaro. Michael is the associate director at the Nelson Center for Climactic Research. I said that right, right? That's part of the UW-Madison. I think we should start by defining what climate change is. You hear everything from global warming to the new ice age. It's something in between those two, I think.

 

Michael Notaro:

 Yeah, I think that's right. Climate change is a better term than global warming, because climate change really involves more than warming but changes in weather patterns, changes in snow and ice the entire system.

 

Shelley Ryan:

So, the patterns are changing.

 

Michael Notaro:

 That's right. We also want to differentiate between climate and weather. We can, as an example this past winter of 2011-12 we had about six degrees above normal temperatures. March was about 14 degrees above normal. So we have an extremely warm winter. Then we had an extreme drought in the summer of 2012. Those are examples of weather variability. You can't necessarily point to those and say that's climate change. Those events may become more frequent with climate change. So that's the difference between events and actual climate change.

 

Shelley Ryan:

So that event may become a more regular part of the pattern but right now, it's too soon to tell.

 

Michael Notaro:

That's right.

 

Shelley Ryan:

But you have some research that's kind of saying we're going in that direction of warmer.

 

Michael Notaro:

That's right. We've had some studies such as Chris Kucharik and Shawn Serbin did a study from 1950 to present looking at weather data throughout Wisconsin collected by residents of the state. That's showing that the state has modestly warmed about 1.1 degrees since 1950s. That small change produced a substantial change in the growing season. It's lengthened it by a couple of weeks.

 

Shelley Ryan:

For us gardeners, that's kind of a good thing.

 

Michael Notaro:

There are some good things and some bad things. Some of the other favorable things besides the warming is that it's wetter, by about three inches more rain a year particularly in the autumn. But then associated with that there's changes in weather extremes. We have the lengthening of the growing season by a month that's occurred. That's been favorable.

 

Shelley Ryan:

You said there were some observations made by Aldo Leopold.

 

Michael Notaro:

That's right.

 

Shelley Ryan:

That supports the climate change.

 

Michael Notaro:

Not only do we have the weather data, we have impacts. This is what's called phenology data which is the birds and plants timing spring events, when they emerge. Aldo Leopold Bradley, back in the '30s and '40s was collecting data on the timing of these events of birds and plant blooming in southern Wisconsin. And later, back in the '70s to '90s, his daughter Nina collected the same data in the same region, and found that a lot of these events are occurring roughly three weeks earlier. So it's already emerging and having effects on our environment.

 

Shelley Ryan:

Then you can look at that. It's still not a hundred years of data but you can say that, yeah, climate change is happening based on that kind of information.

 

Michael Notaro:

Yeah, that information definitely supports it. I've also done a study on plant hardiness zones. The plant hardiness zones, which you'll often see on the back of seed packets tell you what kind of plants will grow in an environment is based on the coldest temperature of the year. Usually our plant hardiness zones range from 3b in northern Wisconsin to 5b around Milwaukee County. We're projecting, by the end of the century potentially that Milwaukee County can even approach 7a category

 

Shelley Ryan:

Wow.

 

Michael Notaro:

Which is more, anywhere from central Illinois to central in northern Mississippi-type plants.

 

Shelley Ryan:

In some ways, this is a good thing because there's a lot more plants we can grow and grow them longer. But then I also think of certain plants like peonies, that need a certain amount of cold to bloom, to grow. We may lose some of the plants at the northern edge. Birches that are at its southern edge may retreat further north, too.

 

Michael Notaro:

Yes, we could have substantial changes in our gardens. And we know through the Wisconsin Initiative on Climate Change Impacts, we've developed climate projections for out state such as six degrees warming and changes in weather extremes. The changes in weather extremes are the ones that gardeners have to be concerned about.

 

Shelley Ryan:

You can't predict them for one thing.

 

Michael Notaro:

That's right, and they have large impacts on the garden. The growing season may lengthen by a month, but we may have roughly three weeks more 90 degree days by the mid 21st century.

 

Shelley Ryan:

Oh, I don't like that!

 

Michael Notaro:

And more frequent summertime droughts and dryer soils. Some of these can have direct effects on our gardens. We may have to mulch more often. We may have to plan for invasive species which may spread in warmer temperatures.

 

Shelley Ryan:

Well, invasive species I'm assuming insects coming up from the south. Probably new diseases, as well. So, as gardeners, it sounds like we're going to have to adapt. You mentioned mulching, more watering being aware of these things coming up at us. Are there other things we can do?

 

Michael Notaro:

Right, and dealing with climate change the Wisconsin Initiative on Climate Change Impacts has really pushed adaptation which is adjusting to the climate change lessening negative effects by adapting to change. There's also mitigation where you reduce emissions. In terms of adaptation, if you go to our website we have some examples of how to adapt to climate change.

 

Shelley Ryan:

So there are things we can to do help. We will have a direct link to your website. Thank you, Michael.

 

Michael Notaro:

Thank you.

 

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