Three billion to join human race in one lifetime

In 1804, Malthus predicted that the planet's booming population would cause an imminent starvation crisis. At the time, there were one billion people on Earth. Today, there are 7.7 billion. By 2050, the world's population will have swelled to more than 9 billion. And, by the end of the century, just 80 years or one average Western lifetime from now, the number of people alive will peak at 10.9 billion. At this point, according to the United NationsAn international organisation focused on keeping peace. Its refugee agency, the UNHCR, aims to assist refugees around the world.'s latest report, the numbers will level off due to plummeting fertility rates in wealthy nations. In the 1990s women had 3.2 babies in their lifetime. By 2050, it will be down to 2.2. Couples need to average 2.1 children to replace themselves and keep the global population stable. And as we live longer and longer, thanks to better medical care, our populations are ageing. By 2050, one in six people will be older than 65. Now, that figure is one in 11. Already, inn Japan, there are only 1.8 working-age adults for every one retiree. Across much of Europe and Southeast Asia, states are facing a looming pensions and social care crisis as money to look after the elderly runs dry. In other areas, births are still soaring. In 2027, India will overtaken China as the most populous country. The number of people in sub-Saharan Africa, where clean water, food and sanitation are in short supply, could double in the next 30 years. The population is growing fastest in areas that are least able to support it. Yet, globally, living standards are rising, especially in poorer nations. For the first time, half of the world's population isn middle class. While wealthier populations reproduce less, they also consume more. As affluenceWealth and prosperity. grows in South America, Asia and Africa, so will demand for fossil fuelsFuels made from decomposing plants and animals, including coal, natural gas and oil. These fuels release carbon dioxide, causing global warming., fertile soil, drinkable water, oil and other finiteLimited in size or extent. resources whose consumption is driving global warming and destroying ecosystemsComplex networks of living things that rely on each other to survive.. Estimates vary but, by 2050, experts say there will be between 25 million and one billion climate refugeesAnyone fleeing conflict or persecution is defined as a refugee by the UN as a refugee, regardless of where they are from., driven from their homes by the devastating impact of the climate crisis. Can the Earth support 10.9 billion people? Not according to ecologist William Vogt. His thesis is that we must radically reduce consumption and limit the population to avoid ecological catastrophe. We are burning through Earth's resources, and demand will only increase as affluence grows — while the poorest are left to fight each other for the scraps. But Vogt's contemporary Norman Borlaug represents another view. The agricultural revolution more than doubled overnight the amount of food Earth produced. We have not stopped innovating since. In the same way, technologies (like green energy and lab-grown food) can solve the problem of finite resources whilst saving the environment. Q & A What do we know? In fact, the 10.9 billion figure was revised down from 11.2 billion in the UN's previous report. Eight countries will account for almost half the world's projected population growth between now and 2050. They are India, Nigeria, Pakistan, the Democratic Republic of Congo, Ethiopia, Tanzania, Indonesia, Egypt and the US. It took 127 years for the world population to double from one to two billion. By contrast, since 1960, world population has grown by about one billion every 13 years. What do we not know? The accuracy of the predictions. It depends on many factors. For example, in places where the birth rate is very high, like in sub-Saharan Africa, improved sex education and access to contraception could help limit the population to more sustainable levels.KeywordsUnited Nations - An international organisation focused on keeping peace. Its refugee agency, the UNHCR, aims to assist refugees around the world.