At Climate Desk, we like to call them—affectionately—our “pet trolls.” (You know who you are. Hi!) They are regular readers that pepper us on Twitter and Facebook with one of several climate myths upon the publication of every article, sometimes with freakish speed. One of the most popular myths is this: Global warming isn’t real because it’s really cold outside; climate models are thus full of sh*t. So, here in 90 seconds, is our attempt to explain something we interact with every day, in all sorts of ways, from flying in a plane, to getting a loan, to betting on a horse: computer modeling.

Our video features Drew Purves, from Microsoft in Cambridge, UK, a statistics whiz specializing in modeling the climate and ecosystems. Think of him as the Nate Silver of carbon. You can read about his latest research project, a rallying cry to model the entire world’s ecology—that’s right, the entire world—in the latest edition of Nature.