Science behind the headlines – beyond seven billion people
// December 9th, 2011 // Science Communication
We reached a big milestone last month as the world’s population exceeded seven billion people for the first time. Looking behind the headlines was Paul Willis at the RiAus and a panellist of scientists and journalists on Tuesday (event details here.)
In the 20th century we added five billion people to the Earth. Before that, we had only added two billion in total. Part of the reason is a decreased death rate, due to better medical facilities, coupled with an increase of food made possible by the Haber process that produces nitrogen fertiliser from nitrogen in the air. The chemistry makes it possible to, on some level, make food from air.
But population increase is not exponential. The UN expects the population to level off at 10 billion in the next fifty years, after a dramatic decrease in fertility, which no one anticipated.
“It is unconscionable to have a policy to increase mortality!” says Graeme Hugo, Director of the Australian Population and Migration Research Centre at the University of Adelaide. “The only way forward is to decrease fertility, that’s the only thing on the table.”
The world has done very well to reduce fertility, halving it since the 1970’s.
However, in some areas of Africa and isolated pockets in Asia it is not dropping as fast as expected. Two years ago East Timor each woman was having around eight children. The continued high fertility may be because we’ve taken our foot off the pedal when it comes to efforts like increasing contraceptives, women’s education and emancipation.
But it’s not all about the numbers, and that was the key point the scientists spoke about on Tuesday. Population is a complex issue, and has to be considered in connection to age and spatial distribution and consumption of goods.
The cost of looking after an aging semi-majority (the baby boomers) is a worry for some political movements. Balanced age groups are important to ensure the number of dependents and the number of workers is stable.
Migration may not change the global numbers, but it’s important for people are spread out in the right way. That means considering how many people a local environment can sustain in terms of food and water.
Consumption is also critical. One baby born in the United States consumes the equivalent of 30 babies born in Africa according to Udoy Saikia, School of the Environment, Flinders University (here’s a relevant link.) “People in developed countries should limit their consumption,” says Hugo. “In many developing countries, consumption needs to go up because they’re not consuming enough to be healthy.”
One way for more developed countries to limit consumption is to go vego. A more vegetarian diet is able to support more people for the same number of resources. Bring on the lentils!
This Tedx talk on the topic, I can’t recommend it enough.
Scientists agreed that coverage of the seven billion people story has been pretty good overall, far better than stories about migration.
One issue they mentioned was the trend to look for a magic bullet, fixing just one thing to solve the whole population problem. It’s also hard for journalists with limited inches to talk about all the factors in a complex issue like population science.
Stopping population growth won’t work unless you take consumption into account, as well as the other factors. There needs to be a holistic approach. That doesn’t end (or even start) with policy – everyone needs to make a decision to change their consumption.
How many Australians should there be? There is no magic number where everything will fall into place. There are definite demographic problems regarding aging populations and dispersion (or lack thereof).
The scientists agreed we need a policy that allows for sustainable growth. They said it would devastate Australia if we stopped population growth tomorrow, but it would be also devastating to have uncontrolled growth.
“Every day we waste about 40% of the food (in Australia),” says Saikia. “There is some hope that the 10 billion population can survive very well, depending on distribution and consumption.”
Paul Willis summed up by asking whether Australian’s should “be concerned, not alarmed.” It’s not the end of the world, but we do need major changes and responses to population dynamics, says Hugo. “Be concerned, AND alarmed – about consumption,” says Saikia.
This post was also featured on the RiAus website.
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