course, contributes no energy) from
the calculation.
Of course, some estimates in the
book are intended only to be good to
within a factor of two or so, and occasionally somewhat poorer, since
MacKay’s goal is often just to put a
rough upper bound on a potential
source of energy. His estimate of
tidal-stream power, for instance,
combines physical arguments with a
perusal of the tidal charts in a nautical almanac, and seemed to us (as
yachtsmen) to rather underestimate
the ubiquity of strong tides around
the UK’s coast. Such an approach
does open the book to criticism, particularly from specialists; indeed, it
could easily become a victim of its
own success if policymakers and
others begin to regard its figures as
accurate final judgments. That would
be a shame, for it would traduce one
of the book’s intentions, which is to
enable readers to do their own calculations – in fact, its original working
title was “You go figure it out!”.
To this end, MacKay is very keen
that the book should be digestible. It
is well illustrated, and all algebra is
confined to the technical chapters (in
effect appendices) that make up the
last 90 or so pages. The physicist will
find much that informs (and occasionally amuses) in these chapters, particularly in those on cars and planes. The
former runs a long way on very little
algebra, and in the latter the basic
physics of a jumbo jet’s energy consumption is shown to scale down quite
well to fit an albatross.
In the main text, however, all that is
needed is basic numeracy and familiarity with exponential notation. For
this reason the book would be a good
way of introducing teenagers to how
real physicists work – all the more so
because MacKay’s treatment of en-
ergy is much more positive and empowering than either the school physics curriculum or most environmental
literature. By exposing both the data
from which his book’s conclusions
are drawn, and the methods and arguments by which they are reached,
MacKay in effect says “You need take
no-one’s word for it. You can work
it out for yourself, and this is how.”
Various reviewers have said something
along the lines of “every policy maker
should read it”. We would rather advocate it as a book every budding physicist should read – and perhaps also as
the one every working physicist would
like to have written.
Niall MacKay (no relation to David) is a
mathematical physicist at the University of
York, UK, e-mail nm15@york.ac.uk.
Roger Edgar was co-founder of Infrared
Engineering Ltd, a spin-off company from the
physics department of Imperial College London
Web life: Clim’City
URL: http://climcity.cap-sciences.net
So what is the site about?
Like the popular SimCity computer-game series
that inspired its name, Clim’City puts players in
charge of a virtual city and allows them to choose
how it develops. To win, players must reduce
greenhouse-gas emissions by 75%, slash energy
consumption by 40%, boost the share of renewable
energy by 60%, and help citizens and businesses
adapt to changing climate conditions – all within
50 years. The game offers a number of different
ways to do this (developing wind power, insulating
buildings, improving public transport, etc), but it is
up to the individual player to decide which changes
to implement, and in what order.
Who is behind the site?
It was launched in early 2009 by the Cap Sciences
museum in Bordeaux, France. The full site is still
only available in French, but the game itself has
been translated (imperfectly but adequately)
into English.
What is it like to play?
The main screen of Clim’City shows a model city
with mountainous outskirts, a populous coastline
and various structures in between. Clicking on
these structures brings up menus of possible
actions, along with information about their
consequences. For example, at the city’s power
station, you can choose to burn cleaner fuel oil or
natural gas instead of coal, or to research (and then
implement) carbon capture and storage. Some
actions are contingent on others: you can also
make the power station run on wood, but only if you
have already developed the city’s biomass
production facility. Each action consumes political,
enterprise or citizen “points”, which represent the
cost of getting different parts of the city to adopt
your plans. When you run out of points, time moves
forward by a year. A series of graphs lets you see
your city’s chances of meeting its goals.
This is harder than it looks. Any tips?
The game provides numerical information about
how long each action will take to implement, and
how much energy consumption and/or emissions
will fall as a result. Paying attention to these
quantities – rather than simply picking actions
that sound nice – will improve your final score. In
addition, graphs showing how much energy/
pollution each sector of the economy is using/
producing can help players identify which areas
require more action. It is also worth noting that a
few actions, like reinforcing sea defences, do not
reduce emissions or energy use. However, they can
prevent players from losing valuable points if, say, a
massive storm strikes the city later in the game.
Who is it aimed at?
With its cartoon interface and easily mastered
gameplay, Clim’City looks like a kids’ game.
Indeed, the French-language site contains a wealth
of educational graphs, maps and interviews that
are not yet available in translation; science
teachers on good terms with their school’s French
department might find some opportunities here for
jointly taught lessons. But be warned: this game is
far easier to play than it is to win, and adults as
well as children will struggle to meet the
demanding (some might say impossible) targets
for victory.
How realistic is it?
Very – almost to the point of being discouraging.
Consider the following. If you do nothing, both
emissions and energy use will tick inexorably
upwards, in line with current trends. Some of the
most effective actions – like closing the city tip or
producing hydrogen at the solar power station –
are really expensive, and require action on multiple
fronts. It is far easier to run out of “enterprise
points” than any other type, so even when you have
plenty of political will and an enthusiastic citizenry,
there is still only so much change that industries
can absorb each year. In fact, the game’s only
unrealistic aspect may be the relative ease of
meeting its target for “adaptation”; if the current
furore over energy-saving light bulbs is any
indication, people are far less willing to change
their habits than this game assumes. Still, as a
simple (and addictive) demonstration of the
difficult energy choices facing the world, Clim’City
is hard to beat – in more ways than one.
