I recently got interested in the idea of exponential growth in the "real world," and a little bit of research got me thinking about the possibility of framing a math project surrounding the idea of exponential growth and (environmental or social) sustainability implications.
For example, one of the things that I spoke to my Algebra 2 students about is the idea that as our world population grows exponentially, so does our utilization of non-renewable resources, our CO2 emission rates, and our general waste emission. With technology also exploding exponentially (Moore's Law), our world economic output also increases exponentially. I dug up some statistics that the world economy grows, on average, 4% a year, which means that in one person's lifetime (less than 60 years), it'll multiple 10 folds. In a century, it'll multiply 50 folds. That's insane. Even if a part of this "growth" is due to inflation, the increase in our economic output is still growing substantially over time. The earth's finite resources cannot support even a steady linear growth, let alone a sustained exponential growth. The exponential pattern we experience now is simply not environmentally sustainable, and it points to the hypocrisy of our governments who simultaneously support environmental concerns and continued economic expansion.
Similarly, I did some digging on inflation rates, causes of inflation, and rises in public four-year university tuition as an example of inflation. The trend is exponentially increasing at a staggering rate, which comes back to a social justice issue, on the front of social sustainability. I told the students that the in-state tuition of UW is already twice as expensive now as when I attended university in California 10 years ago, and I was an example of a "regular" person who barely made it through college at those former tuition rates, working part-time and on financial aid. The more I think about it, the more I think that there is a prime opportunity here for an end-of-year project linking math and either social or environmental implications. Students can research data sets of their interest, create mathematical models, and then create a PSA to educate the school community about the social and environmental implications of such trends.
Thoughts? Have you done such a project and have resources that I can look at? I want to find a balance of leaving it completely open for them to choose something they care about, and providing some general framework to ensure it's going to be productive and meaningful. But, I've been thinking a lot about this! Brainstorming slowly for the end of the year...