The United Nations is estimating that next Monday, the world's 7 billionth inhabitant will be born. It is a milestone that has economists, scientists and politicians wondering whether the earth's population is reaching breaking point.
Humanity has expanded rapidly since the 1800s, when the population first reached the billion mark. In the past generation, the number of people on the planet has doubled. Demand on resources, natural and man-made has inevitably increased with more mouths to feed, home and provide for. Can Mother Earth cater for her growing brood?
The United Nations says it is both a challenge and an opportunity. A new report to be published this week predicts the world population could reach sixteen billion by the end of the century.
Campaign group Population Matters says the earth cannot sustain the growth. Pressure on the environment means it will be much harder to address issues like biodiversity and climate change stating "our numbers and activity increasingly encroach on the natural world." Humanity's reliance on the world's ecosystem, for regulating the atmosphere to using plants for medicine and crops, could all be negatively impacted by a population that outgrows its habitat.
Others policy-makers argue population growth is not the issue. They cite figures that illustrate where population growth is happening fastest. The areas with the biggest families tend to be the poorest. The UN figures suggest 42% of the world's population live in areas with fertility at below replacement level, where there are fewer children and older people. 40% live in countries where people are replacing themselves. 18% live in high fertility areas, like sub-Saharan Africa where on average women have five or more children. These low income countries are responsibly for more than half of the population growth of the last generation, but only 12% of the global carbon emissions. By contract the richest nations that have contributed only 7% to the global population growth have in turn contributed 29% to the increase in emissions.
While some fear the impact of food shortages and an inability for technology to grow alongside the population, others believe the real impact will be the growth of an older population with a smaller youth, as is becoming the pattern in richer countries. Health and social care bills will increase for governments and individuals while productivity will be decreased, say analysts.
Jack Goldstone is the professor of public policy at Washington's George Mason University, "We thought that overpopulation was going to force humanity to expand outward to the stars. That doesn't look like the problem at all. And the policy framework isn't set up at all to handle these longer-term issues."
The demand on the economy will match the demand on food. Over a billion people in the world already go hungry. An increasing population will mean increasing food production levels, more fertilizer, and a more efficient use of existing resources.
Steve Jones, the professor of genetics at University College London advocates a change in diet. Americans now eats on average two tonnes of food in his lifetime with both meat and dairy consumption on the rise. Food production, he advocates should move to crops that feed people directly, rather than to grain that fattens animals for meat.
The National Geographic this week has a counter tool measuring the size of the world's population as it ticks across to 7 billion. The next generation, it predicts will live longer (living to 100 will be the norm) but potentially in only the richer and more densely populated areas. Competition for resources will get fiercer and more embattled. For those who see it as an opportunity, it is one to take stock of the resources the world has and ensure they are distributed more fairly in the future.