In the last couple of years, our planet’s human inhabitants have crossed two major thresholds, one of which indicates major problems ahead, and the other of which offers a glimmer of hope. We’ll get back to the hopeful bit in a minute, but let’s begin with the problem, which you’ve probably seen in the news lately: according to the UN’s estimate, the world population just crossed the 7,000,000,000 mark. Various models suggest it’ll probably plateau somewhere between 10 and 15 billion about a century from now – at the high end, that means more than two people walking around for every one that’s alive now.
Can you imagine the implications? Most of them are worrisome. Assuming we continue to do business as usual, nearly every resource on the planet will be strained. We would have to double our agricultural production to meet demand, and even if this turns out to be possible, we could easily end up doubling our land and water use as well, and doubling the runoff of fertilizers and pesticides. Speaking of runoff, all those people will need access to clean water, which even today is much rarer than it ought to be. They’ll also need to heat their homes, cook their food and get from place to place, so demand for fossil fuels will skyrocket too. And that’s to say nothing of the carbon footprint that’ll be left by an extra 3-8 billion humans.
Of course, we don’t necessarily need to do business as usual – we can be a lot smarter than that. Sustainable power, organic and genetically engineered crops, smart water use, urban planning, and even this cheap solar lamp are all ideas that, if taken to scale, could minimize the impact of all that extra population. I hope to discuss these solutions and more right here in this space. But for today, I want to look at the issue through a slightly different lens, and that’s where the other big milestone comes in.
As of 2008, more than half the people in the world live in a city. Again, this is the first time in history, and again, that number is only going up for the foreseeable future.
What does this have to do with the population problem? Far be it from me to suggest that urbanization, by itself, is an automatic solution – but the fact is, the increasing city-ness of the world’s residents provides a host of unique opportunities for more sustainable, efficient and equitable living.
Take land use, for example. I’m deeply worried that as population expands, we’ll simply take over more space, thereby despoiling remaining areas of natural beauty, threatening ecosystems and driving more species to extinction. But cities support much higher densities – they allow for upward, rather than outward, expansion. Similarly, water and power can be allocated more efficiently when people are living close together, and shared transportation networks like subways become more cost-effective. There are also a host of emerging technological innovations that will transform the city for the better, from responsive architecture to distributed communication networks to integrated renewable energy sources (more topics for future posts!).
Urbanization does bring a host of challenges. Witness the vast suffering within Mumbai’s Dharavi shantytown, or Rio’s unofficial favelas. This is a particular concern when you notice that the population and urbanization trends are geographically aligned: Africa and Asia will see both the largest population boom and the fastest rate of urbanization, suggesting that cities there are likely to rapidly outgrow their capacity.
What do you think? Can urbanization act as a counterweight to population growth? Can we combat the associated problems in a comprehensive way, or are we just trading a frying pan for a fire? And is it possible to slow or reverse either trend, even if we wanted to?
Personally, I remain hopeful that cities, on balance, will make life better for those 8 billion or so new humans, and perhaps more importantly will help ensure that our tiny planet can continue to support all of us, however many we may be.