Today’s problem concerns the way that biosphere points are presented. The current system uses two factors:
Deforestation (how many square miles of rainforest are destroyed each year)
Forest Fires (how many square miles of northern forests are destroyed each year)
Each of these factors has a “species extinction rate” attached to it: how many species are made extinct for each square mile of destroyed forest. This in turn leads to a factor called “Extinction”, which counts up the total number of species rendered extinct each year. On an average year, we’ll get about 24,000 species destroyed, for a game total of about a million or two destroyed species.
This has a serious flaw: under extreme conditions it’s possible for a player to destroy more forest land than there actually is, and wipe out more species than there actually are. To prevent this, I must shift from differential (how much stuff is destroyed each year) to total (how much stuff still exists each year). This would mean that the three factors (Deforestation, Forest Fires, and Extinction) would be replaced with three new factors: Rainforest Lands, Northern Forest Lands, and Biodiversity. Instead of seeing graphs of the differentials each year, the player would see graphs of the totals declining each year.
The weakness of this approach is that the total quantities in each case are fairly large. For example, there are about 8 or 9 million catalogued species on the planet; during the course of one game, the player might kill one or two million of these, producing a decline of only about 10% of the total. The same problem would exist with Rainforest Land and Northern Forest Land. But it would be more reliable in that the numbers could never go below zero.
One small possibility is to include ecosystem collapse in the system. Thus, when the biodiversity of a given ecosystem falls below a minimum, the entire ecosystem collapses and many more species are destroyed. This, however, adds complexity to the system. I don’t know whether I should add it.