The number of species at time step t is given in equation E.2:
where and are “expert guesses”, is a scaling parameter and is the temperature change with regard to the previous year.
A brief examination of the formula lets one guess, that the exponential decay given by the parameter will dominate the evolution of species numbers, but let’s have a look. I have assumed a simplistic temperature model: temperature change after 2000 follows an arcus tangens function with an initial slope of 2°C/century and levels off at various . Here’s the result.
As expected, the exponential decay dominates the behaviour of all curves, has rather little influence. By the year 3000 the model rates the number of species at 4% to 5% of todays level. I expect this result to be robust with regard to changes in the temperature model.