Hi. It's Paul Andersen. And this is disciplinary core idea ESS3C. It's
on human impacts on earth systems. When the Apollo 17 astronauts were leaving the earth
they took the most famous image that was ever taken. It's called The Blue Marble. And when
people viewed this in the 1970s it changed them fundamentally. They finally had seen
a picture of the earth. And they saw that it wasn't infinite. That changes we make to
our earth are going to be passed forward in time and on to future generations. And so
humans have impacted and continue to impact the earth. We're impacting all four of the
spheres on our planet. So we're impacting the earth itself of the geosphere. And so
agriculture is an incredibly important to us. It's how we grow our food. But if we're
not taking care of the soil we can get soil loss. If we're not rotating our crops we can
see soil loss like we saw during the Dust Bowl. Also as we're mining, as we're digging
up the metals, the minerals that we need, we're changing the surface of the planet.
And it just doesn't come back on it's own. We're also changing the water. The hydrosphere.
So when we dam a river and change it into a reservoir, we're changing that natural path
of the water. And we're also causing greater evaporation on that surface of the reservoir.
So we're upsetting this whole water cycle. And as we move water to where we need it,
so as we irrigate, we're changing the flow of those natural rivers. And lots of times
we're bringing unintended consequences. We're bringing salt into areas. And that salt can
eventually cause salination of the soil. And we're going to have less crops. We're also
changing the atmosphere or the air itself. And so smog is caused by particles that we're
moving into the air. But we're also putting invisible particles. We're putting greenhouse
gases, like carbon dioxide into the atmosphere. And that's increasing the temperature over
time. And we're also changing the biosphere. We're changing the life on our planet. As
we deforest the rain forest, that life is not going to come back. As we over fish an
area, the fish aren't going to come back. And so now we've created a nonrenewable resource.
And likewise when we change our environment we're changing areas like coral reefs. We're
causing them as we increase the temperature to bleach. And as they do that, the whole
food chain that's built upon that is going to fall down as well. And once a species goes
extinct, it doesn't come back. So another thing we need to address is this idea of development
over time. We have certain countries that are developed. And certain countries that
are developing. We have wealthy nations. And the United States happens to one of those.
We have a high GDP per capita. And that's just a measure of the wealth. But in a lot
of countries, like in Africa, we're going to have lower wealth. Now one thing that's
interesting between this, is that if you are a wealthy nation like we are, you're going
to be consuming more of those natural resources. So this map almost looks identical. What it
is is oil consumption per capita. And so the United States is consuming a lot of that oil.
We're increasing the amount of fossil fuels we put into the atmosphere. But other countries
are going to become developed as well. And so as China and India become developed and
they have way more people than we do, it's going to put more stress on our planet. It's
not all bad news. If we use our resources wisely, if we manage our resources we're going
to do okay. And so an example of that could be water pollution. Our water sources used
to be awful. And that's because we were getting water from the rivers and then dumping sewer
back into it. And so as we treat that sewer, as we treat that water as it flows out, we're
going to decrease that water pollution. As we start to recycle a lot of our resources,
as we recycle our aluminum and metals and plastic and all of that, then we don't have
to dig it out of the earth again. And so now we've got a renewable resource. A great example
of this is when I was young ozone depletion was a really big deal. And so we'd been using
chloroflurocarbons. And what they were doing was reducing this protective ozone layer.
And so we as a country and other countries started to reduce the amount of the use of
these CFCs. And the ozone is starting to rebuild. And it's not going to be the threat that it
was at one point. And so this idea is important. The idea of sustainability. If we look at
the human population over the last 10,000 years, we see an exponential growth. We see
an explosion of people on our planet. We now exceed 7 billion people on our planet. And
so we're going to have to make that sustainable. We're going to have to make sure that the
resources we have on our planet will last through future generations. And the scientists
are able to see what is happening into the future. And the engineers are going to be
able to design sustainable systems over time. So how do you teach this? Well in the lower
elementary grades you want students to understand that our life, if we want to have a comfortable
life, we're going to effect the world. We're going to effect the environment. And if we
don't want to effect it in a negative way, we can do things like reduce, reuse and recycle.
And if we do that, we're still going to impact the world. All humans impact the world. But
we're going to reduce that effect. As we move into the upper elementary grades we want to
start talking about the impacts humans are having on our planet. Be it the land, the
water, the air and the biosphere or the life on our planet. We also want them to understand
that if we're wise in our management of these resources, we can reduce our impact. So sewer
treatment is a great example of that. In the future we'll probably have to regulate what
we're putting into the air, just like we regulated what we're putting into the water. There's
not a lot of regulation on greenhouse gases across the world. And we're probably going
to have to come to grips with that. Also we need to talk about extinction. Once species
are gone, they're gone forever. And they're not going to come back. And as we see increasing
in developing nations and as we start to consume more and more and more, we're going to have
to be equitable in the amount of resources that we're consuming and the impacts that
we're having on our planet. And then as you move into high school you really want to talk
about this term sustainability. The population has increased, will continue to increase.
We have just a set number of resources on our planet. So we're going to have to start
listening to scientists. And we're going to start creating engineers and scientists so
they can create a sustainable future. And if we don't we're going to have some negative
consequences. And I hope that was helpful.