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My name is Nat Lifton
and I'm a Geologist in the Earth Atmospheric and Planetary Sciences
and the Physics and Astronomy departments at Purdue.
A I've always been drawn to science and technology
um but it really it's the scale of Earth's processes that fascinate me.
Um I can in fact I can tell you the instant that I decided to become a geologist
A I was on a field trip to the San Andreas Fault
a which ran down a deep canyon in the mountains north of Los Angeles
and as I was standing on one side of the canyon
I was visualizing that I was standing on one tectonic plate
looking at the other another tectonic plate on the other side of the fault
on the other side of the canyon
and that the scale of that visualization just completely blew my mind.
So I feel like I'm so lucky to be able to have the intellectual freedom
to pursue the types of things that interest me
a such as you know being able to ask
and to try and answer the questions about how the world works
about how the processes at the earth's surface work.
It's just so much fun for me a that my job doesn't even seem like work.
So I study ways of figuring out how long a rock or sentiment
has been exposed at or near the Earth's surface
and how fast various processes work that active shape the landscape around us.
I do this using certain rare atoms that are produced in the minerals within the rock or sediment
by high-energy cosmic rays from space if you can believe that
so kind of nuclear physics.
A these can only penetrate into the top meter or two of the earth's surface
so if we know how quickly these atoms are produced
in a rock or mineral that's been exposed at the surface
then we can say something about its history at or near the surface.
So one of the rare atoms a that are known as cosmogenic nuclides is what I work with
and that a atom is carbon-14.
So it's produced in rocks from oxygen atoms a by cosmic rays
different from the organic carbon-14 that's better known as a dating tool.
So a number of these cosmogenic nuclides are either stable
in in other words not radioactive
or are are radioactive but decay very slowly
so on the order of hundreds of thousands to millions of years
Carbon-14 on the other handdecays much more rapidly
so on the order of thousands of years
and comparing the amounts of these long live nuclides with the amount of carbon-14 in a rock
allows one to determine whether a sample has been continuously exposed or buried and re exposed etc.
so I've applied this in a in Arctic Canada and in other glacial environments
to study the advance and retreat of glaciers in particular
a which can act to shield the underlying rock from cosmic rays
so this allows carbon-14 in the rock to decay
while the levels of the longer living nuclides don't change very much
so that allows us to say something then about the history of the burial or exposure of the rock.
So climate change is nothing new on the Earth.
In fact it's been varying throughout a Earth's history.
A the the aspect of climate that is new
is that the rate that it's changing now is unprecedented
and it's going to challenge life on the planet to adapt in ways and with speeds
that we haven't had to since we've been here as homo sapiens.
Ecosystems have evolved under very slowly changing conditions over many millions of years
a which allow for adaptation or migration as climate changes
to the environment and organism have evolved together in a finely tuned balance as a result of that.
because it has the time to do it.
The CO2 that we're putting into the atmosphere and ocean since the industrial revolution
has been sequestered in the earth for many millions of years
but we're burning through it in an instant of Earth's time span
and this threatens the balance between a the ecosystems and their environments
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