In 1804, the world population stood at 1 billion. Today, it’s more or less 7 billion. How did the population grow so big in 200 years? Just as you’d guess: As medicine and agriculture practices improved, more people began living long enough to have families of their own. But this infographic video from NPR does a superb job of telling the story, using glasses of colored liquid to visualize births (water drips into the glass) and deaths (it escapes through the bottom).
So is the population going to keep ballooning at this rate? Are we looking at 49 billion people by 2212? Don’t sound the alarm bells just yet. Depending on how you look at it, the glass is half full–the UN predicts that the world population will top out at 10 billion–or half empty: It’s unclear whether we’ll have enough food and energy to support everyone.