How many species have been described by humans? (Hint: a quick Google search will get you some results, make sure you find the most legit!) Do we think we are anywhere close to describing them all? How could we tell?

How many species could survive inside Biosphere 2 indefinitely? What determines the number of species that can persist in a given environment?

Should we worry about the rate of extinctions? Can we build some Biosphere 3’s and 4’s in response to climate change and be okay?

I’ll be giving a talk at Biosphere 2 10:30 Saturday addressing these very questions. If you’ve been putting off that visit you always meant to take, this might be a good weekend.