I am toying with the idea of requiring by IB students to use their independent project as a call for action.  They already need to perform an experiment or analyze published data; I am thinking about requiring a next step - act on their findings.  Last year was my first year teaching the course, and many of the experiments were on acid rain.  I do NOT want to read 10 studies of the effects of acid rain on bean plants again!  As I was looking through this part of the course, several ideas popped into my head about where I can direct students this upcoming year:

Stream study, especially involving flooding in some way

Electricity useage - we have solar panels on the school roof.  How does the pre/post data compare?  Can we reduce it even further?

Porous pavement - study the feasibility of installing some of that if the county plans to replace pavement at our school

If students MUST grow plants (they seem to love to do this) maybe we could figure out a way to investigate the effects of elevated CO2 on plants and their nutrient content

I'm going to look further at the baybackpack site and the MAEOE site: https://maeoe.org/resource-library

Another, bigger-and-probably-for-another-year project would be to ascertain our Maryland Green School certification level and recertify/start the process.