How do trees affect the weather?

Sure, you know that trees have an impact on climate change: to wit, fewer trees mean more atmospheric CO2. But did you know that trees can actually impact local and immediate weather? Learn about why you should love trees even more than you do.

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Episode Transcript

Speaker 1 (00:01):
Welcome to Stuff you Should Know from house Stuff Works
dot com. Hey, and welcome to the podcast. I'm Josh Clark.
There's Charles W. Chuck Bryant, which makes this Stuff you
Should Know podcast. I don't think I should love us
see finished please, um, because of that horrible house fire.

(00:33):
It's good, but it's not quite poetry. What was it?
I don't think I shall ever see something so beautiful
as a tree? Is that right? A poem is beautiful
as a tree? Is it a poem? Okay? Yeah, which
is really something because what was that Longfellow or Whitman?
Now I want to say, like Joyce Carol Oates, No, no, no, no,
we should look this up. Okay, well, while you're looking

(00:55):
it up, that's really saying something because insert poet's name here.
Um really was taking his own craft to task and
appreciated his or her own task. And it was still
saying that a tree is lovelier than any poem, which
is a real oded nature. So I said, Joyce Carol Oates,
but I was in fact wrong. It was in fact

(01:16):
Joyce Kilmer, who was a dude. I thought for sure
it was like Longfellower. Huh boy, he is a it's
a mama's boy if I've ever seen one right there,
right poems about trees? What he expect? Well, that's a
great line. Yeah. Uh so we botched that one all
over the place. Yeah we did, but we're not going
to start over. It's okay. This isn't a poetry slam.

(01:37):
This is stuff you should know that. We would never
slam poetry. Um. Instead, we would spend our time, as
is our want, promoting trees, talking about trees and how
great they are. And u uh Val Kilmer his great grandfather,
Joyce Joyce Kilmer. Uh, he kind of had it dead on,

(01:58):
because trees are not only beautiful, there are um functional
and as uh, either Longfellow or Whitman said, nothing can
ever truly be beautiful unless it's also functional. Oh yeah,
they didn't really say that. Somebody said it. Uh. And
you know, we live in Atlanta, Georgia for those of

(02:19):
you don't know, and we basically live in the middle
of a forest. If you ever go up on the
building here or any building in Atlanta and you think
you're in like downtown or midtown, you just take a
look out there and you realize, man, there are trees everywhere.
There's a lot of trees, and people that are from
like the West or other places where they or not
as foresty come to the Deep South. Sometimes they're like, wow,

(02:41):
you know, so in the middle of the forest. It's
a city in the forest. Yeah, and it's pretty nice.
It's nice. Nice living up and down the East coast's
kind of like that, right, um, And we actually live
in a temperate, deciduous hardwood forest area. Nice, look at
you from what I understand. Although there's a lot of
pine trees too, there's those Georgia pines. Yeah, that's true.

(03:02):
I may be incorrect, coniferous. Well, here's the deal with forest. Um.
The author of this I take slight issue of our
planet is is forest land? And she says it's mostly
concentrated in ten countries the US, Canada, Russia, Sorry, Russian Federation, Brazil, China, Australia,
Democratic Republic of Congo, Indonesia, Peru, and India. Great, but

(03:27):
no mention of like Europe, Uh, Germany, Sweden, Finland, Norway,
like serious forest going on? There is there enough? I mean,
I know there's the black forest in Germany. Yeah, like
the boreal forest basically ten degrees above or below the equator,
you're gonna have rainforest, and then between roughly like fifty

(03:50):
and seventy ish degrees. Uh, you're gonna have boreal forest,
which is like Europe and Canada and Russia, and you know,
it's like a serious stents forest. And she didn't mention
Europe at all. Those are the northern climes forests. Yeah,
we're talking coniferous pine, spruce, birch, beautiful, beautiful trees. And Canada,

(04:11):
of course America is at is lousy with trees. Yeah,
there's a lot of trees there. It's like Atlanta. One
point five million square miles of forest land in Canada, right,
so they got it going on up there. It's and
that that sounds like a lot, and it is, but
it's still it's alarming to consider that we lose about um,

(04:32):
thirteen million hectears heck tear is I think one point
five acres? Is it? I believe? Uh, well, I do
know that only I'm sorry, I'm not getting one more
thing wrong in this episode. You go ahead, and I
do know that only one I'm sorry. Only roughly of

(04:53):
the Earth's original forest land is still intact today. So
over the years has been lost due too, things man
made and things natural. And apparently we lose an amount
of forests that's about the size of grease every year.
So we need Canada. We need Canada's trees. Yeah, and

(05:14):
you know there are things like forest fires, disease insects,
competition between species, acid rain, things like that happen. Of course,
that one is actually man made. And then there's things
like logging and slash and burn practices, just when you
cut down trees and burn them to create a field.

(05:34):
Uh so those are things that man is doing to
make trees go by by man and nature are conspiring
to rid us of trees, which we need. And the
hectare by the way over two acres. Yeah, we'll look
at that in choke corrections for the first time. All right, So, Chuck,
everybody loves trees, not the least of whom would be

(05:56):
Joyce Kilmer. But we like them too, We like having
them around, and they actually serve a little bit more
of a function than you would think. Yeah, apparently it's
not just oh they give us oxygen, which is what
everyone thinks, which is great. They actually can affect the climate,
and the climate is defined as a period of weather
patterns in a localized area over about a thirty year

(06:19):
at least stretch. I think not many people realize that
everything else is just weather, yeah, you know, anything under that,
although I imagine when you start getting into yeah, they'll
be like, okay, alright, that's climate. Fine, that is true,
and our planet is warming. We're not going to get
into the whole rigamarole of global warming and all that entails,

(06:41):
although we should do that in earnest one day. But
the climate is warming here on the planet, and it
is heating up by about one to one and a
half degrees per years, or at least over the past century. Yeah,
And I mean that's an important qualifier too, because it
wasn't supposedly until the beginning of the Industrial Revolution, starting
around eighteen thirty that um after that we started to

(07:04):
see temperatures rise thanks to global warming. So the fact
that it rose by one to one and a half
degrees in a century, that's significant, even though it doesn't
seem like much, not to us. You can breathe into
your hands and raise the the weather around your face,
um by more than just one degree. Also be foggy, yeah,
you know, and a little smelly, depending on you know,

(07:30):
So how can trees affect our climate? Really three main ways? Right, yes? So, Uh,
the first is to um lower temperatures, which is something
they do themselves. Uh. Next, they reduce energy usage, which
is a new phenomenon for trees because we've only had
like air conditioning for fifties sixty seventy years. But it's

(07:53):
a new gift that trees give us. And then, um,
they actually remove air pollutants, which is pretty awesome. All right,
So let's start with the first one. They lower temperatures.
They act as a natural air conditioner for the world
in a way through a process called evapo transporation, no
huge shock. That is a mix of uh, not a mix,

(08:13):
but both things going on at the same time. Evaporation
and transporation, both of which released moisture into the air
one by way of drawing water from lakes. And we
talked about in our clouds episode. U's how we eventually
get clouds. And then transporation is when trees pull up
water through the roots, work its way up through the tree,
and then eventually leave from the leaves. Right, And we

(08:36):
don't actually see like after like a heavy rain in
the summer, you can see the evaporation going on. Yeah. Um,
and probably what you're seeing off of the trees is
actually evaporation off of the leaves transparations of invisible but
over like the course of a year. Um, a large
oak tree supposedly can transpire about forty gallons of water.

(08:58):
That is crazy, that's a lot. Yeah. So they come,
they bring up all the nutrients through the water, they
take what they can pee it out their leaves into
the atmosphere as vapor, not as urine right now. But
since that's going on, especially when it's going on at
the same time as evaporation, it produces water vapor and
it can actually decrease the temperature. That's right. Uh. And

(09:21):
like you said it, you know, a big thing now
and it's not now. Actually, that's the funny thing. A
lot of things that people do now to be green
are things people did many years ago as just a
way of life. Homesteaders. Yeah, Like Emily's grandmother and actually
my grandmother too, they were like, you know, they composted
and did all that stuff because it was a way
of life and they didn't have trash pick up homesteaders. Yeah,

(09:43):
and now we're like, oh, yeah, I composts like, big deal,
that's nothing new. I mean, it is a big deal.
You should do stuff like that. But you know what
I'm saying, people like nowadays think they invented the green
movement when it was our forefathers really and mothers. Yeah,
I guess just as long as you're not like burning trash,
yeah you're doing good. So what led me on that
mini rant against our people of this age is that

(10:07):
passive heating and cooling is a big thing now, but
it was a big thing way back when because before
they had air conditioners and things, they would, you know,
plant trees where it made the most sense. Are not
plant trees, but plant houses between trees where it just
to grow where it made the most sense. So like
they say, I think a tree to the north of
your house, in the south of the house can cut

(10:28):
down on your energy expenses by how much. Well, a
heating costs two day percent and cooling costs by And
you want to plant one at least one tree to
the west and one treat to the south. Deciduous trees, yes,
that's the key. If you plant a big old magnolia tree,
you're gonna be like want, want, want, because while it'll

(10:48):
cool your house in the summer by keeping some sunlight
off of conjecting shade. In the winter time, it will
still keep sunlight off of it. With a deciduous tree,
they lose their leaves so the sun shines through the
branches to in the wintertime, So it cools your house
in the summer by producing shade, warms your house in
the winter by lightning the sunlight through. Yeah. And I
love magnolia trees, but boy, you ever had one on

(11:10):
your property, it's a pain. Waxy leaves that don't disintegrate
ever or by degrade, they just are there. And then
those grenades, which were great as a kid when you
played war, but they're not so great when they're all
over your yard. Uh. And then pine trees, which I
love to look at as well here in Georgia, they're
also a big pain. Yeah, they can be. Yeah, but

(11:32):
they well, yeah, they don't lose their leaves on an
annual cycle. They just lose them all the time. But
they're always they always have the needles, that's true. But
with the magnolia, though, you also get the lovely scented
flower and you can snip those off and put in
a little water bowl in your kitchen. It's like a
natural air freshener. So my neighbor has stead well, my

(11:53):
neighbor has a magnolia and one branch hangs over into
my yard, and so I will clip flowers, uh and
not really have to deal with much of the waxy leaves,
which is kind of the best of both worlds living
the life man so so passive heating and cooling if
a transporation. That is a great thing that trees do.
And they can also help cut down on what's called

(12:15):
the heat island effect, which is bad in cities. Yeah,
we have that bad here. Um. So there's this thing
called the albedo effect right where if you are dark
colored wearing a dark shirt. You're wearing a black shirt
right now, that's right, you would be hotter in that
shirt than you would if you were wearing a white shirt. Why.
I'll tell you why. White shirts reflect sunlight. Black shirts

(12:37):
absorb sunlight and trap heat. Same thing with asphalt, same
thing with dark roof tops. And when you put all
this stuff together, it actually absorbs all this heat traps it.
And so when you're in a city, it's frequently much
harder by several several degrees than it is out in
the suburbs where you have more trees and lawns and
stuff like that that aren't going to absorb the heat

(12:59):
quite as much. Yeah. And I lived in Yuma, Arizona,
as you know, a lot of white cars in Uma, Yeah,
not a lot of black cars. And they actually have
I might have mentioned this before, they have like almost
carpet that they put on their dashboards and it's like
a thing. It's like fit to the car and it's
velcrowd on and it saves your dashboard. And they have

(13:21):
carpet on your dashboard. Yah, pretty much. And you go
to the video store at the time, this is you know,
they had video stores back then in the you know,
mid nineties, and they would have you know, melted video
cassettes on display because or like the ticketmaster tickets, like
don't leave them in your glove box or this will happen.
They catch fire. It looks like they caught fire, but

(13:42):
they it was just heat exposure. Is that the average
ticketmaster employee Okay, yeah, yeah, don't just pay a million
dollars for fees. Uh. So that's the heat all in
effect in Atlanta, um five to eight degrees hotter and
Phoenix in nineteen fifty it was six degrees warmer than

(14:04):
the nearby cass Grande Monument. I don't know why that's
that is, Oh, because in two thousand seven it was
fourteen degrees. Okay, I get it. Yeah, so it's getting
hotter in cities as urban sprawl and the black tops
of asphalt take over the world. Yeah, exactly. Phoenix isn't
exactly like a work, live, play, walkable community. It's pretty

(14:25):
dry v e right, or at least golf CARDI yeah, yeah,
Well the same with Atlanta. So you've got sprawl which
is going to increase the urban heat island effect. Phoenix
is big, big time sprawl. Yes, but trees help counteract us.
They cut it down. They say, no more of this.
We're going to provide you passive energy savings and if
appo transpiration. And while we're at it, you know all

(14:49):
this horrible air that you're breathing, we're gonna filter it
for you. We're gonna throw that in as a bonus
included in the low price. Uh. They will filter dust, ozone,
carbon monoxide, other kinds of plutants, um and through photosynthesis
they actually remove CEO two, which is a greenhouse gas,
as we all know, they remove it and release oxygen instead,

(15:13):
and they can actually even store it. Yeah, they they
sequester it in the forest soil. And apparently that soil
depending on where you are thinking a deciduous temperate forest. Uh,
that's that carbon dioxide will be stored for anywhere from
ten thousand to a hundred thousand years. Yeah. I think
we talked about that. We talked about carbon sequestration before

(15:37):
or um, what was it desertification? Desertification maybe or earthworms. Yeah,
we play in the dirt a lot. Yeah, the earthworm one,
that was a good one. That was a good one. Um.
So the trees are filtering out the air, but they
actually and this is a little known Ronald Reagan actually

(15:58):
once said trees pollute more than cars do any day
of the week, and he was not entirely wrong. Yeah.
I don't quite get this. The photochemical smog okay, so um,
when it gets hot, trees have this volatile organic volatile
organic compounds, two of which are turpenes and isoprenes, okay,

(16:18):
and they give them off off of their leaves. It's
just like it's too hot, I gotta get rid of
my VOCs and is supremes in particular act as a catalyst.
They speed up um the breakdown by sunlight of of
nitrous oxides into ozone, and ozone is a big contributor
to small. So basically, when when the trees are like

(16:40):
giving off these volatile organic compounds, they're accelerating the production
of small indirectly, you know. So when you mix sunlight
photo with these chemicals photochemical smog, it's from the breakdown
of like um car exhaust into ozone, which scratches our

(17:01):
eyes and makes us a cheating it hard to breathe.
So we should cut down all the treats pretty much.
That's Ronald Reagan talk. No, of course not. And that
is that's like the one negative effect that we can find, right,
oh yeah, other than that trees, well, that and falling
on somebody or your house or something. Other than that.
Trees are great, right. That happens a lot Inlanta with

(17:21):
the heavy rains. Well, it does because we went through
a drought cycle where the roots all started to come
towards the surface, and then when you get a heavy rain,
the trees no longer planted like it was, and it
just tips over. Just the other day, another guy sitting
in his car. Man, they love talking about that on
the news, it'll be like crime, crime crime. Oh, tree
fell over, let's go cover that instead. That's that's the

(17:44):
Atlanta News because the boy there's a lot. I don't
you watch the local news? Uh? Sometimes? Really? Yeah, I'll
see I'll see it, you know, out of the corner
of my I haven't watched the local news since I
was probably in high school. It's good on like the treadmill,
like when you can't hear anything. It's good for that.
When they're in front of the varsity interviewing somebody about
something important, a tree following over, what do you think

(18:05):
about this? Yeah, okay, so we're talking about global warming? Um,
can we actually plant trees and get more forest land?
He actually helped us out. That's how Pearl Jam used
to do to offset the carbon usage or emissions for
their tours. Did you know that they planted trees? Yeah.

(18:26):
They calculate like how much like their jets emitted, um,
like increcent greenhouse gas the CEO two I think specifically,
how much like the their fans cars emitted, like on
the way to the venue, like through for a whole tour,
and then they calculated and then like they would buy
an equal amount of trees or however much you know,

(18:47):
carbon a number of trees kid sequestion. That's how much
they got the offset their tour. And then al Gore
started doing it one I don't It was really close
to about the same time. Um, and everybody thought, this
is great, this is a great idea. Uh. But there's
a couple of problems with it. One, once you cut
down that tree, like that carbon is released in the
atmosphere prematurely. And then secondly they there was a two

(19:10):
thousand study seven study that said it depends on where
you put the tree. If you put in the tropics,
then it actually will cut down on global warming. Um,
because in the tropics, trees not only cool the place
the place by Evappo transporation, it's actually warm enough that
they produce clouds, which cool the rest of the earth.

(19:34):
It's like a cloud factory down there on the equator. Yeah.
We hit that in the rainforest podcast, right Okay. Um,
in the middle climates where we live, it's pretty much
a wash. If you plan a tree there for a
carbon offset, it's not going to really have a net effect.
If you go up to the borealis forests, which is

(19:54):
a term you taught me recently. Um, it actually can
contribute to the heating boreale for us, well, the Aurora boreal,
which is what I understand now. Um, it can contribute
to the heating of the planet because remember the albedo effect. Well,
up there, it's cold enough so that that green canopy

(20:15):
that's trapping sunlight and hence warmth, is actually going to
raise the temperature. So this cold climate, cold part of
the Earth that you used to balance out the overall
global temperature, if you plant trees up there, it'll warm it.
Where was Pearl Jam planting trees? Do you know? I
don't know. Hey, we mentioned Ticketmaster too. They stuck it
to those guys. Yeah they did. Remember Eddie Vetter war

(20:36):
like that German World War two helmet and court really
Yeah he was not happy. Yeah. I saw a lot
of Pearl Jam shirts at that Sound Garden show last night. Yeah,
it was people. Uh, you know, it was great. And
my buddy ended up getting hooked up with V I. P.
Seats because he knows the guy at the Tabernacle. So
we were literally like front row of the balcony. You're
right in the center. Um, but the setless man, they

(20:58):
gotta work on that. Oh really, Yeah, it's one of
those deals where I know, I don't I don't want
to complete nostalgia tour, But when you're coming back after
that long, no one wants to hear seven songs from
your new album. Oh yeah, you know what I'm saying. Well,
I mean, if you're trying to kick start your career again. Yeah, yeah,
I mean there was a decided energy change in the
room when they were doing like a bad motor Finger

(21:20):
and screaming Life and Louder than Love, and then they
were doing whatever that new album is called, which I
don't care for, here Comes the Sunshine. Like everyone was
just kind of like, okay, another one of these, except
for like, you know, the drunk eighteen year old near me. Yeah,
this is the only song I've heard finally one I recognize.
But yeah, good, he sounded great, man, he's amazing. Well,

(21:42):
I'm just glad that Pearl Jam fans and Sound Garden
fans are apparently getting along now. Sure it was rough
there for a while. Yeah, and then you factoring Alison Chains,
it got really ugly. Go look it up kids music
of the nineties. You got anything else about stupid trees? No? Oh,
I do. I have another thing? So you remember the

(22:02):
two thousand seven study. I was just talking about where
I misused borealice a two thousand thirteen study this year. Yeah,
I said, you know what nuts to that nuts to
Lawrence Livermore Laboratory. We have a computer model that says
that if we doubled the amount of forests, including boreal forests, um,

(22:24):
and especially I think boreal forest as soon as possible,
we would lower the global temperature by a full one
degree fahrenheight. So we would all set that twentieth century increase.
Possibly yeah for the last hundred years. That's crazy. Yeah,
and um, we would increase summer rains by ten to
fifteen percent all by wow. Yeah, well at the earliest.

(22:47):
But still so is there a plan in place or
was that just like we should do this? Somebody's like,
what can I do with a computer model today? Yeah?
All right, we'll good for them. Yeah, plan a tree.
I'm sure there is a program in your community. We
can go out and uh sponsor a treat to be planted. Yeah,
but God help you if you plant one in the
northern clients because you're you're part of the problem. All right,

(23:11):
you got anything else? No, If you want to learn
more about trees and weather, type those two words into
the search part how stuff works dot com And I said,
the search parts means it's time for a message break,
all right, listen to mail time. Great. I'm gonna call
this one hatty totty from the land of Cotton and

(23:34):
falk now because that was the subject line. And I
was like, you know what, No, I'm still good. I'm
gonna ease it. Uh. And I just kind of like
the cut of this guy's jib. That's why I'm reading it. Um, guys,
the name is David Holbrook and I'm from a little
town of Waynesboro, Mississippi. I'm currently a senior in my
final semester at the University of Mississippi for my BEA

(23:56):
and political science. Go ReBs. Should we say that sec team? Um.
I also work part time in the parts department of
the local GMC dealership here in Oxford, and I'm a
bouncer on the weekends at one of the bars on
the famous Oxford Square. Boy, have you ever been there? Oxford?
A lot of fun? Yeah, great, college down. I'm a
huge fan and just found never found the gut to

(24:18):
write you guys until today. Um. I really enjoyed after
my third minute little yeah, I've put Panda paper. Um.
I really enjoyed throwing around the knowledge I learned from
y'all in the workplace, although I sometimes think my co
workers get a little jealous and my girlfriend as well. Yeah,
I have to say one of my favorite things about
the show, I will admit this is really random, is

(24:39):
when Chuck whispers things at the end of sentences, which
he does a lot. I have no idea that was
a pretty poor example, but yeah, I agree. Um. I
always laughed so hard because sometimes it seems as though
Chuck does really not mean for us to hear those bits,
but he forgets he's in front of a mic. That
might be true. Um. I also really relate to you

(24:59):
all in the way this guy's a fraud. What did
he say? You all? Now I did? It's y'all, okay,
all right? He checks out. Really relate to y'all in
the way that it seems we have held many jobs
in our past that makes us well rounded people. Well,
I feel like I'm rambling on with this nonsense will

(25:20):
continue with the fan mails and maybe with some filled
with more interesting and beneficial substance. Thank you from the
land of Cotton and William Faulton to David Holbrook Jr.
Random fact about me ps. I grew up on a
chicken farm. We have eight chicken houses with anyway of
from two d fifty to three hundred and fifty tho
chickens at one time in eight houses. That's what he said.

(25:44):
Those are big chicken. Yellow chicken outs are huge. Well
that's great. What's you think, David Holbrook Jr. Thank you.
Sure one day we will get a David Holbrook the third. Yeah,
we keep doing this long enough. Yeah, David Holbrook Jr.
Thank you very much for writing in check. Did you
practice reagionail? No? And I kind of went back and
forth with the accent like Kevin Costker and Robin Hood right,

(26:07):
or Dances with Wolves or water World. Uh, but I'm
impressed and I think like you hit all the emphasis
just perfectly. I'm from the South ballcorn like horn is
in my blood. Yeah, I'm more like that little chicken
with the glasses. I'm a chicken hawk and you're a chicken. No. No,

(26:28):
the little one who never talked, who just read all
the time. Yeah, yeah, yeah, the little jerk. Yea uh.
If you are I don't know, stereotypically regional, we want
to hear from you. Agreed. Um. You can send us
a tweet to s y s K podcast. You can
join us on Facebook dot com, slash Stuff you Should Know.

(26:48):
You can email us we understand. You can send it
to stuff podcasts that discovery dot com and check out
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(27:15):
you by b a s f V chemical company.