What does “life expectancy at birth” really mean? If a child is born today in a country where the life expectancy is 70, they can expect to live until they are 70… not exactly. In simple words, it’s the number of people of different ages dying that year, and shows a snapshot of these overall “mortality characteristics” that year for the population. While medical advancements have improved many aspects of healthcare, the assumption that human life span has increased dramatically over centuries is misleading. Life expectancy has increased so much because more of us are making it that far, but not because we’re living far longer than we used to as a species. “The life expectancy of Roman women actually increased with the decline of fertility. The more fertile the population is, the lower the female life expectancy.” Valentina Gazzaniga “Once the dangerous childhood years were passed… life expectancy in the mid-Victorian period (17th Century) was not markedly different from what it is today.” Judith Rowbotham and Paul Clayton “Being pregnant adversely affects your immune system. Then you tend to be susceptible to other diseases.” Jane Humphries One-third of infants died before the age of one, and half of children before age 10, but after that age your chances to reach 60 or 70 were pretty high. Having said that, life span also in ancient Rome probably wasn’t much different from today. What about the population? The global population has a continuous growth, it took over 200,000 years of human history to reach 1 billion, and only 200 years more to reach 7 billion. The long-term global population growth is difficult to predict, in particular because the growing pressures on the environment, energy resources and global food supplies, this is just the projection made on the actual conditions.