The UN is set to announce that the population of the planet has now reached seven billion people. But will this number continue to rise in future years - and if so, what could this mean?
Watch this three-minute BBC video and answer the questions about it.
1 When did the world's population reach one billion people?
2 What are the three reasons mentioned for the increase in population?
3 What will the earth's population be in 2100?
4 What problems is Sub-Saharan Africa facing today?
5 Why might the population decrease?
You can check the answers by reading the transcript below.
We’re living in an era of huge population growth. It took until 1804 for there to be one billion people on the planet. By 1927, that figure had doubled. In just about thirty years, it hit three billion. Then look out quickly: it rose to four, five, six and now seven billion. The world’s population is growing by 200,000 people a day.
Lack of space shouldn’t be a problem if everyone lived in one megacity the density of Paris then in theory the entire population of the planet could fit into France with room to spare. So, will our numbers keep rising? Almost certainly yes, for several decades. More people are in their reproductive years than ever before, more children survive thanks to better health care and sanitation and people are living longer. The UN’s best estimate is there will be eight billion people by 2025, nine billion by 2050 and ten billion by the end of the century. A higher UN prediction has the population at nearly sixteen billion by 2100.
Much of the increase will be driven by poor countries in Sub-Saharan Africa, many already with inadequate food and water. In the next forty years, Ethiopia could see its population rise from around eighty million to one hundred and forty-five million. Contrast that with Germany; a similar population to Ethiopia now but this could fall to seventy-five million by 2050.
Indeed there is a scenario that sees the world’s population falling. The UN’s lower estimate for 2100 is just over six billion people; a billion fewer than there are now. Why? Well, global fertility is already falling. In 1950, women on average had five children each; it’s now down to two and a half. Small variations in fertility could have a big effect on population size in the future. In much of the world, including Brazil, Europe, Russia, Japan, even China, fertility has fallen so much the populations are reliably predicted to fall later this century.
But whatever the long-term projections for the coming decades, we can expect more and more people on the planet, way beyond the seven billion milestone we're now passing.