CHAPTER 3
Measuring and Monitoring Progress Toward Sustainability
To learn to live sustainably, we’ve got to know how well we’re doing. But
measuring the health of a forest or an ocean is an extremely complex
task: One has to collect a huge amount of data, get the most information
possible given limited resources, and then make sense of that data. Every
step raises mathematical challenges. Chapter 3 focuses on thesechallenges.
What’s the climate like right now?This question might seem bone-headedly obvious, answerable in amoment of poking your nose out the door. But that would be confusing two things
that are very different: climate and weather. Weather describes what the
atmospheric conditions are at a given moment, while climate describes the
average atmospheric conditions for a particular place at a given time of year. In
sustainability science, we are interested in both, one for short-term effects that
could become more drastic and the other for long-term trends that have
implications for the health of our planet. Short-term weather forecasts, over five
to seven days, have become quite good, but long-term prediction of weather –
such as whether Chicago will have a white Christmas next year – is impossible.
Predicting climate is even more involved, particularly for a small region, like a
city.
So, what’s the weather like right now?It’s that question that we might feel can be answered by going outside andlooking. But figuring out the current weather around the entire globe turns out to
be a remarkably difficult problem.
If weather forecasters had a nice, tidy grid of perfectly reliable weatherstations evenly spread around the world and extending up into the atmosphere,
all they would have to do is to consider the readings. But what they have is far
from that. See Figure 1, which shows weather monitoring stations in Europe,
which are located according to funding and local interest. That’s not so
convenient for weather forecasters, whose models need to know the temperature