How Does CS Help Mitigate Global Warming?
In lecture and in the discussion sections, we are starting to
appreciate one of the major aspects of CS -- the importance of coming up
with algorithms (programs) that are efficient in terms of the amount of
time (e.g., number of steps) it takes them to complete.
For example, a binary search of a trillion entries (e.g., a Google
index of web pages) would be much more preferable to a linear search --
the former taking around 3*log(1 trillion) = 120 setps whereas the
latter taking 2 trillion steps.
Coming up with efficient ways to solve a problem is important not
only because the results would be obtained faster (milliseconds as
opposed to decades), but also because it means that we would impact the
environment much less!
As some of you may know, computers are now one of the largest
consumers of energy (and thus contributing to carbon emissions and
global warming). So, by making programs/algorithms (whether for a Google
search or an XBox game) even slightly more efficient (say by 20% or 50%)
could make a huge difference on the environment.
Indeed, to elucidate this point, some scientists went through the
trouble of figuring out the carbon footprint of a Google search -- how
much energy it takes for Google to respond to a search query?
According to Google, an individual search needs 1 kilojoule (0.0003
kilowatt hours) of energy, which is equivalent to about 0.2 grams (0.007
ounces) of carbon. Google says in a blog post (check it
here) that this amount of energy is consumed by the human body in
about 10 seconds. Another way to look at this is that doing 1,000
searches on Google has the same carbon footprint as driving a car for
one kilometer (0.6 miles). Just think about the energy savings resulting
from using Google to do research at home versus having to drive to a
local library (not to mention all the energy needed to keep the library
lit, air-conditioned, etc.)
By coming up with efficient algorithms to solve problems (like
searching and sorting and others we will see as examples in this
course), CS can make significant contributions to saving the planet.