Inspired by the Drake equation, a formula that aims to quantify the probability of extraterrestrial civilisations, I started thinking about the possibility to develop my own speculative mathematics. I am proposing a formula that helps us to understand the relation between future development of human population, human culture and global environment. Taking the advance of humanity and its culture as defining elements for the future, and acknowledging that these activities will have an accelerating impact on global ecology, the following equation is established: h(umans) + c(ulture) = n (global ecology) * f(uture). In this version culture and ecology are safely divided on both sides of the equation. By moving ecology to the other side, the division is disrupted: (h+c)/n=f. Although I do not want to make any claims to the mathematical validity of these speculations, the equation might help to further discussion about the relationship between our actions and a possible future. Instead of dreaming about conquering the stars, I rather dream about new possibilities that are close at hand.