Hi. It's Paul Andersen and this
is disciplinary core idea ESS2D. It's on weather
and climate. Weather is what we see outside.
Like these thunderstorms right here. But climate
is different. And so students tend to confuse
those. Weather is what it looks like right
now. So it's what it looks like today. And
climate is what it looks like over a long
period of time. And so they're both measuring
the same thing. Things like temperature. Things
like precipitation, wind. But it's really
time scale. Weather is what it looks like
right now and climate is going to be over
time. So what causes weather? What causes
climate? Well a number of different factors.
It could be the amount of sunlight, oceans,
atmosphere, ice, landforms, life forms. All
these things interacting together are going
to give us our weather today or our climate
over time. So when you look at our planet
what you see are oceans and landforms. And
those oceans and landforms are going to receive
energy. Receiving energy in the form of sunlight.
And what they do with that energy is going
to determine the weather. They're going to
take in that energy. They're going to release
some of it. They're going to absorb some of
it. They're going to redistribute that on
our planet. And that's going to create the
weather that we have. And so some major redistributions
on our planet would be the currents. And so
current is going to be flow within the water
of the ocean itself. It's caused by temperature
and changes in salinity. But if we're looking
on the atmosphere itself, what's going to
move our weather around are going to be the
winds. And that's going to be caused by unequal
heating of the earth. And also the spinning
of the earth is going to create winds that
tend to travel in the same direction. So in
Montana we tend to get our weather from the
west. And that's because of the spin of the
earth. Another big thing that effects our
climate is going to be the greenhouse effect.
The way that works, and it gets its name from
a greenhouse. And so if you've ever been in
a greenhouse, especially on a hot day, it's
really hot there. Even if its cold outside,
its warm on the inside. How does it do that?
Well it's receiving sunlight. So it's receiving
energy from the sun. But what the greenhouse
is doing is as that energy is converted into
thermal energy or heat, it's going to keep
it close to our planet. And so we're not losing
that as light. But that heat is actually reflected
back down to the earth and it traps this heat
near our planet. Now eventually we're going
to lose that heat, but it's going to stay
there for a longer period of time. So we have
what are called greenhouse gases. And those
greenhouse gases in our atmosphere are going
to slow that loss of heat. The big four are
going to be methane, that's natural gas. Carbon
dioxide. Water vapor. So that's water that's
in a gaseous form. And then nitrogen oxide.
And so all of these are going to act to hold
that heat near our planet. And so changes
in climate or changes in our weather over
a long period of time are really going to
be due to two things. Changes in that atmosphere.
And therefore changes in our greenhouse effect.
And then the earth's reflectivity. In other
words, how much of that energy from the sun
is just reflected back into space? And how
much of it is going to be held here? And so
if we have something really really white,
something really, really light, like a glacier,
it's going to reflect a lot of that light.
But if we have something really really dark,
like a parking lot, for example, it's going
to have a, it's going to hold more of that
heat. And so what we can get is climatic changes.
And those climatic changes can occur over
a very short time scale or over a long time
scale. So what's an example of a short time
scale? A big volcanic eruption can throw so
much sediment into the atmosphere that it's
going to reflect more of that light. Not as
much of the light is going to get to our planet.
And so we could get a cooling of our planet
by having so much of that sediment in the
atmosphere. A meteor impact could do the same
thing. But we could also have slow changes.
And so we can get small disturbances in the
amount of radiation coming to our planet.
And those over time can cause small fluctuations
in our temperature. And ice ages are caused
by that. As we add the arrival of life, a
lot of those cyanobacteria started doing photosynthesis.
It produced more oxygen. Put that into the
atmosphere and actually changed the make-up
of our atmosphere. And so a lot of these occur
based on feedback loops. Feedback loops are
going to be loops that either keep it stable
or push it more away from stability. And so
a quick example of that is as we heat our
planet we're actually melting a lot of the
permafrost. And as we do that releases methane
into the atmosphere, which is a greenhouse
gas which is going to cause it to melt faster
releasing more methane into the atmosphere.
And so humans can have an impact on this as
well. And so we're creating more carbon dioxide
in the atmosphere. And we're doing that through
the burning of fossil fuels. And this is just
going to be looking at carbon dioxide levels
in over the last forty years. And what that's
going to do is increase our temperature. Whereas
we melt more of that arctic ice cap, what's
going to happen to the reflectivity of our
earth? It's going to change and that's going
to cause an increase in temperature as well.
So how do you talk about all of these in school?
Well you want to start by delineating between
weather and climate. And so what is weather?
Weather is what it looks like today. So it's
going to be the temperature. It's going to
be how much sunshine we have. Do we have rain?
Do we have wind? All of that is going to weather.
And something that a lot of elementary teacher
do well. What it looks like today. As we move
into the upper elementary grades we want to
make sure that we're clear in the difference
between weather and climate. Weather is what
it looks like today. Climate is going to be
what it looks like over time. They're the
same measurements, but they're over a long
period of time. So here we're looking at maximum
temperature. And minimum temperatures. And
you could figure out which of these is during
the summer and which of these is during the
winter. As we move into middle school we want
to talk about the factors that effect this.
And so it's going to be all of these factors
are effecting the weather and the the climate.
One of the big ones is going to be the sun.
And the angle of the sun hitting our planet.
If it's near the equator we're going to get
direct light and we're going to have higher
temperatures. And if we're far away from that
we're going to have lower temperatures. But
again, as the earth turns, and as it turns
on its access, we're going to get changes.
But again all of these factors are effecting
the weather and the climate. And students
should understand that it's incredibly complex.
And so since so many factors are effecting
our weather, it's hard to predict what's going
to happen. And when you look at a weather
forecast, what you're really looking at is
a probability. They're looking at a lot of
different models of what it might look like
today. And 60% of those models are predicting
that it might rain. But it might not. Because
it's really really complex. Other things in
middle school we should talk about is how
oceans, especially, are taking in energy and
redistributing that energy on our planet.
And the importance of greenhouse effect. And
how greenhouse gases slow the loss of heat
from our planet. As we move into high school,
we should talk about climate. And how climates
can change over time as we change the atmosphere
or the reflectivity of our planet. And we
can have small and large time scale differences.
An example of this could be the ice ages.
But we also have to talk about how humans
can impact the climate as well. As we increase
the amount of carbon dioxide in the atmosphere,
due to the burning of fossil fuels, we're
simply going to increase the temperature on
our planet. And you can see this. We've got
1,000 years of data. But this is going to
be the temperature that we have now. And it's
just going to get warmer and warmer. But it's
not that bad. Because we can make impacts
on that. We can decrease the amount of these
greenhouse gases and we can turn it around.
And so that's weather. That's climate. They're
incredibly important. Really important in
our future. And I hope that was helpful.
