Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey
Speaker 1: brain Stuff, Lauren Vogel Bomb here. If weather is your mood,
Speaker 1: then climate is your personality. That's an analogy some scientists
Speaker 1: used to help explain the difference between these two words
Speaker 1: that people sometimes get mixed up. In other words, whether
Speaker 1: exists in the short term, it's the state of the
Speaker 1: atmosphere in a specific area during a limited period of
Speaker 1: time I think minutes, hours, days, or weeks. Climate, meanwhile,
Speaker 1: describes long term average trends in weather. And if you're
Speaker 1: interested in the ladder, you'd better know geography. Our global
Speaker 1: climate is made up of many smaller regional climates. Break
Speaker 1: those down and you'll find local variations at just about
Speaker 1: every conceivable scale. And that brings us to micro climates,
Speaker 1: an amazing subject with broad applications for farming, conservation, wildlife management,
Speaker 1: and city planning. The climates are a bit like woven tapestries.
Speaker 1: The big picture is important, no question, but so are
Speaker 1: all the seemingly minor details found inside the larger whole.
Speaker 1: We spoke via email with tomaso Uker, an environmental scientist
Speaker 1: at the University of Bristol. He said he would define
Speaker 1: the term microclimate as quote the suite of climactic conditions temperature, rainfall, humidity,
Speaker 1: solar radiation measured in localized areas, typically near the ground,
Speaker 1: and at spatial scales that are directly relevant to ecological processes.
Speaker 1: We'll talk about that last bit in a minute, but
Speaker 1: first there's another criteria to discuss. According to some researchers,
Speaker 1: a microclimate by definition must differ from the larger area
Speaker 1: that surrounds it. Forests provide us with some great examples.
Speaker 1: We also spoke via email with University of Montana ecologist
Speaker 1: Solomon Debrowski. He said the climate near the ground in
Speaker 1: a tropical rainforest is dramatically different from the climate in
Speaker 1: the canopy fifty meters or about a hundred and sixty
Speaker 1: feet above. This vertical gradient, among other factors, allows for
Speaker 1: the staggering biodiversity we see in the tropics. Likewise, scientists
Speaker 1: observed that partial solar eclipse caused the air temperature of
Speaker 1: an Eastern European meadow to change more dramatically than it
Speaker 1: did in a nearby forest. That's because trees provide not
Speaker 1: only shade, but their leaves also reflect solar radiation. At
Speaker 1: the same time, forests tend to reduce wind speeds, and
Speaker 1: all of those factors add up. Twenty nineteen review of
Speaker 1: ninety eight wooded places spread out across five continents found
Speaker 1: that forests are about four degrees Celsie's cooler on average
Speaker 1: than the areas outside of them. That's around seven degrees
Speaker 1: cooler in fahrenheit. Now, if you hate the cold, don't worry.
Speaker 1: There's a cozy exception to the rule. According to that
Speaker 1: same study, forests are usually one degree celsius or a
Speaker 1: at one point eight degrees fahrenheit warmer than the external
Speaker 1: environment during wintertime, which is pretty cool. So when does
Speaker 1: a microclimate stop being well micro? In other words, is
Speaker 1: there a maximum size we should be aware of when
Speaker 1: discussing them. It depends on who you ask, the uker said.
Speaker 1: In terms of horizontal scale, some have defined microclimate as
Speaker 1: anything that's less than a hundred meters or about three
Speaker 1: hundred feet in range. I'm personally less prescriptive about this. Instead,
Speaker 1: he says, the scales we consider microclimates at should be
Speaker 1: determined by the questions we're trying to answer. Quote, if
Speaker 1: I want to know how temperature affects the photosynthesis of
Speaker 1: a leaf, I should be measuring temperature at centimeter scale.
Speaker 1: If I want to know if and how temperature affects
Speaker 1: the habitat preference of a large mobile mammal, it's probably
Speaker 1: more relevant to capture temperature variation across tens to hundreds
Speaker 1: of meters. But yes, solitary plants have the power to
Speaker 1: generate itty bitty microclimates. Just ask Peter Blanken, a geography
Speaker 1: professor at the University of Colorado, Boulder and the co
Speaker 1: author of a book called Microclimate and Local Climate. He
Speaker 1: said via email, a single stock of corn can create
Speaker 1: its own microclimate through the shading and changes in soil
Speaker 1: properties in the immediate vicinity of the stock. For a
Speaker 1: field of corn, the microclimate created would be much larger,
Speaker 1: extending over the entire field. Many organisms eke out a
Speaker 1: living in some of the dinkiest microclimates you can imagine.
Speaker 1: Take aphids, spider mites, and leaf minor insects. All those
Speaker 1: critters are dwarfed by the plant leaves they feed on,
Speaker 1: and every leaf comes with its own microclimate. Observations show
Speaker 1: that aphids seek out cooler leaves, while those other invertebrates
Speaker 1: prefer warmer ones. Because none of these animals can generate
Speaker 1: their own body heat, leaf microclimates have a critical effect
Speaker 1: on their well being. It no secret that our planet
Speaker 1: is going through some rough times. At the macro level,
Speaker 1: the global temperature is climbing. Nine out of the ten
Speaker 1: hottest years on record have occurred since two thousand five,
Speaker 1: and by one reason estimate, roughly one million species around
Speaker 1: the world are facing extinction due to human activities. The
Speaker 1: uker said on one of the big questions that ecologists
Speaker 1: and environmental scientists are trying to answer right now is
Speaker 1: how will individual species and whole ecosystems respond to rapid
Speaker 1: climate change and habitat loss. To me, microclimates are key
Speaker 1: component of this research. If we don't measure and understand
Speaker 1: climate at the appropriate scale, then predicting how things will
Speaker 1: change in the future becomes a lot harder. Developers have
Speaker 1: long understood the impact that small scale climates have on
Speaker 1: our daily lives. Urban heat island is a term for
Speaker 1: cities that have higher temperatures than neighboring rural areas. Plants
Speaker 1: release vapors that can moderate local climates, but in city
Speaker 1: these natural greenery is often scarce, and to make matters worse,
Speaker 1: plenty of our roads and buildings are made of materials
Speaker 1: that absorb or re emit heat from the sun, and
Speaker 1: vehicle emissions don't exactly help the situation. Still, it's not
Speaker 1: like Boston or Beijing are thermal monoliths. Sometimes the documented
Speaker 1: temperatures within a single city vary by fifteen to twenty
Speaker 1: degrees fahrenheit that's eight to eleven degrees celsius. That's where
Speaker 1: metro parks and city trees come in. They have good
Speaker 1: cooling effects on nearby neighborhoods, Blanket said. Several cities around
Speaker 1: the world have developed programs to increase urban green spaces.
Speaker 1: Tree planting programs and green roof programs have been shown
Speaker 1: to lower surface temperatures, decrease air pollution, and decrease surface
Speaker 1: water runoff or urban flash flooding in urban areas. Today's
Speaker 1: episode was written by Mark Mancini and produced by Tyler Klang.
Speaker 1: Or more in this and lots of other cool topics,
Speaker 1: visit how stuff works dot com. Brain Stuff is a
Speaker 1: production of my heart Radio. Or more podcasts in my
Speaker 1: heart Radio, visit the I heart Radio app, Apple Podcasts,
Speaker 1: or wherever you listen to your favorite shows.