Free Factfulness: Ten Reasons We're Wrong About the World – and Why Things Are Better Than You Think by Hans Rosling

just increasing along a straight line: 1, 2, 3, 4, 5. Instead, the number was doubling like this: 1, 2, 4, 8, 16. Each infected person was infecting, on average, two more people before dying. As a result, the number of new cases per day was doubling every three weeks. The graph showed how enormous the outbreak would soon become if each infected person kept infecting two more. Doubling is scary!
    I had first learned about the effect of doubling at school. In the Indian legend, the Lord Krishna asks for one grain of rice on the first square of the chessboard, then two grains on the second square, four grains on the third square, then eight, and so on, doubling the number of grains each time. By the time he gets to the last of the 64 squares, he is owed 18,446,744,073,709,551,615 grains of rice: enough to cover the whole of India with a layer of rice 30 inches deep. Anything that keeps doubling grows much faster than we first assume. So I knew the situation in West Africa was about to become desperate. Liberia was at risk of a catastrophe worse than its recently ended civil war, and one that would almost inevitably spread to the entire world. Unlike malaria, Ebola could spread quickly in all climates and could travel on airplanes, across borders and oceans inside the bodies of unknowingly infected passengers. There was no effective treatment for it.
    People were already dying in the streets now. Within only nine weeks (the time needed for three doublings) the situation would be eight times as desperate. Every three-week delay in dealing with the problem would mean twice as many people infected and twice as many resources needed. Ebola had to be stopped within weeks.
    At Gapminder we immediately changed our priorities and started studying the data and producing information videos to explain the urgency of the situation. By October 20, I had canceled all my assignments for the next three months and was on a plane to Liberia, where I hoped my 20 years of studying epidemics in rural sub-Saharan Africa could be of some use. I remained in Liberia for three months, missing Christmas and New Year’s with my family for the first time ever.
    Like the rest of the world, I was too slow to understand the magnitude and urgency of the Ebola crisis. I had assumed that the increase in cases was a straight line when in fact the data clearly showed that it was a doubling line. Once I understood this, I acted. But I wish I had understood, and acted, sooner.
The Mega Misconception That “The World Population Is  Just Increasing and Increasing”
    Nowadays, the word sustainability is found in the title of almost every conference I get invited to. One of the most important numbers of the sustainability equation is the human population. There must be some kind of limit to how many people can live on this planet. Right? So when I started testing my audiences at these sustainability conferences, I just assumed that they would know the basic facts about global population growth. Seldom have I been so wrong.
    We have now arrived at the third instinct—the straight line instinct—and the third and last mega misconception: the false idea that the world population is
just
increasing. Please pay attention to the word
just
, which I’ve made italic and underlined for a purpose. This word is the misconception.
    In fact, the world population is increasing. Very fast. Roughly a billion people will be added over the next 13 years. That’s true. That’s not a misconception. But it’s not
just
increasing. The “just” implies that, if nothing is done, the population will just keep on growing. It implies that some drastic action is needed in order to stop the growth. That is the misconception, and I think it is based on the same instinct that stopped me and the world from acting sooner to stop Ebola. The instinct to assume that lines are straight.
    I rarely get speechless, but it happened the first time I asked an audience the following question. It was