Climate-Controlled Earth
Imagine that I could tell you how we can make a difference on the global warming effect. And I don't mean that you should start recycling, or
use less hairspray, or plant more trees. What if we knew just how to massage the quantities of compounds in our atmosphere to regulate our temperature - not
unlike how you might regulate your household temperature with an a/c unit and thermostat? Granted these notions are far off and somewhat
fanciful, but the research I've proposed would let us know if this is possible.
Over the last few decades awareness of a global warming effect has been growing. Scientists have since been struggling to
model and characterize the enormously complex system of Earth. The Earth system has so many intertwined processes
that sorting out what is actually happening is impossible without picking apart each piece. There are many academic teams working
on very select problems - such as modeling how vegetation has a role in the carbon cycle or how ocean currents change based on temperature.
Recently, these models are becoming more and more accurate which in turn makes them more and more useful.
A control approach to this problem will help us in three main ways:
Stability: Using mathematical tools, we can determine first
off if the earth is a stable system. This roughly says that
if we stop doing whatever we're doing to make global warming
worse all together, will the
earth return to the
previous state? A ball at the bottom of a valley is stable
because it will roll back to its starting spot if it is nudged.
A ball at the top of a hill is unstable because it will not
return to its starting
spot. If the system is stable, then we ask how big is the
hill - how far can we push the ball until
it rolls over the other side and won't come back. There are
some useful diagrams of these ideas in the poster below.
Controllability: Systems analysis will also let us know if
there is a variable or set of variables we can use to
steer, or control, the system. Consider two blocks on
the ground. You're able to move the first one but not the
second. Unless the blocks are coupled (string, rubber band,
touching) in some manner there is no way you will be able
to move the second block. If you scale that idea up and apply
it to the earth,
are the "blocks" or variables of the system coupled in such a way that we
would be able to change other "blocks" or variables? In particular, we would
like to determine how we can induce a change in the carbon
content of the atmosphere which has been shown to have a
direct effect on temperature.
Observability: In systems so large it is often difficult
or impossible to measure all of the variables. Here our
tools will determine if we can reconstruct the variables
we don't know with the ones we do. This sounds a lot less impressive and
dramatic than the
first two topipcs, but it is an essential step towards accomplishing
the others.
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