The US has become a nation of suburbs. But will it stay that way?

The American dream in Highland, California. Image: Getty.

Since 1970, more Americans have lived in the suburbs than central cities. In 2010, suburbanites outnumbered city and rural dwellers combined for the first time. Americans live in a suburban nation.

Despite several concerted efforts by city governments to lure residents, suburbanisation continues largely unabated. Census figures from earlier this year show that suburbs of warm climate “Sun Belt” cities in the South and West continue to grow, while cities in the cold climate “Snow Belt” of the Midwest and Northeast decline.

Smaller metropolitan areas with fewer than 500,000 people have also grown, related to an improving economy and job creation in smaller urban centers. This ongoing shift towards the suburbs has significant environmental repercussions.

Since cities and suburbs are home for 8 of every 10 Americans, views of the country are often distorted. Most travel occurs within or between cities. Although rural areas have more than three times the miles of roadways as urban areas, more than two-thirds of the 3trn miles that vehicles travel each year in the U.S. are in urban and suburban areas.

Jobs, too, are overwhelmingly centered around cities. Less than 2 per cent of the American labor force is employed in agriculture.

Many of my students are surprised that the land area occupied by cities is only 3 per cent of the nation’s territory. However, they are correct in that cities have an outsized impact on the economy. In 2016, metropolitan areas contributed $16.8trn to the nation’s gross domestic product, more than 90 per cent of the country’s economy.

With this economic activity comes a high use of natural resources and concentrated pollution production. Although density can be more efficient when it comes to energy use, the sheer number of urban dwellers means that cities, despite a small physical footprint, have a big energy and pollution footprint.

Rising suburbanisation undermines some of the energy efficiency gained by high density living in urban cores. Manhattan has lower per capita greenhouse gas emissions than the suburbs of New York, thanks to factors like apartment living, high costs of car ownership and extensive public transit. Of course, not everyone can afford to live in Manhattan even if they want to. Low-density suburbs are an affordable alternative.

Even so, suburban life can look less desirable. As the U.S. population ages, elderly people may end up “stranded in the suburbs,” far from adequate public transit and unable or unwilling to drive. At my urban university, a mixed use retirement facility was sold out before ground was broken. In the U.S., there are more than 100 university-based retirement communities and the number is growing.


The trend toward suburban life could soon come to an end. Millennials – the generation born between 1981 and 1997 – appear to prefer urban life. They are happier in cities, especially large metropolitan areas, than older generations. The millennial population is growing fastest in metro areas in the Sun Belt and western states, and slowest in the Snow Belt. Topping the list of the fastest-growing metropolitan areas for millennials are Colorado Springs, San Antonio, Denver and Orlando.

Will millennials follow older generations to the suburbs as they marry, have children, recover from the shocks of the Great Recession and find affordable housing? The jury is still out.

Whatever happens, it’s unlikely that people will start to move out of cities and suburbs and back into rural areas. Even though increased connectivity and the internet of things will make remote work more possible than before, businesses will continue to concentrate in urban cores, because they profit from being close to one another. (Futurists once thought the telephone would make crowded cities unnecessary.)

I believe that it’s likely the U.S. will remain a nation of suburbs for some time to come. That will pose a continuing environmental challenge. But it will also bring a new set of opportunities for millennials, who are predicted to overtake baby boomers by next year as the largest generation in the country. How will that generation remake the suburbs to suit their needs and desires without exacerbating current environmental challenges? The answer has profound implications for the nature of cities and urban life in the U.S.

The Conversation

Christopher Boone, Dean and Professor of Sustainability, Arizona State University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

How collecting food waste could slow climate change – and save us money

Cleaning up. Image: Getty.

Food waste is a global problem, and one that’s driving climate change. Here in the UK, the country’s biodegradable waste goes to a landfill, where it breaks down to produce methane, a gas that is roughly 30 times as bad as carbon dioxide.

And yet there’s a simple solution. With the exception of garden waste, which often contains lignin from woody matter, all biodegradable materials, including much of our food waste, could instead be processed in anaerobic digesters. This decomposition in an atmosphere devoid of oxygen produces biogas, which can then be used to generate heat and electricity.

This is more or less the same process that takes place in landfill sites, except that the biogas can’t escape from an anaerobic digester as it can from landfill – meaning the breakdown of the organic matter takes place in an environment that is enclosed and controlled.

The result is biogas consisting of 60 per cent methane and 40 per cent carbon dioxide, which can be burnt in order to generate heat or used as a fuel for vehicles. It could also be used to generate electricity after the biogas has been scrubbed, which can then either power the anaerobic digester or be exported to the national grid. The process also produces digestate, a solid and liquid residue that can be returned to farmland as a soil conditioner. The amount of biogas and the quality of digestate varies according to what feedstock is used in the digester.

This process is already widely used both across Europe – particularly in Denmark, Sweden, Germany and Austria – and elsewhere globally, particularly in India and Thailand. What's more, this move towards separate food waste collection is already happening in countries outside the UK, and its momentum is increasing according to the World Biogas Association. Already, major cities, including New York, Paris, Oslo, Copenhagen, Auckland, San Francisco, Mexico City and many others are regularly collecting food waste from their citizens. The decisions to do so are usually taken at city level, but enabling legislation from national governments assist in this.


At present the UK is lagging behind. Only 109 local authorities in England, about 33 per cent of the total number, collect food waste as of May 2018, according to the Anaerobic Digestion and Bioresources Association (ADBA). Yet making a separate food waste collection mandatory across the UK and running the food waste through anaerobic digesters, could supply enough biogas to generate 36 per cent of UK electricity, according to a 2007 Friends of the Earth report. This percentage could be increased again if food waste from restaurants, cafeteria and retailers was also collected. 

ADBA’s research also suggests that universal separate household food waste collections would trigger the construction of around 80 new anaerobic digester plants for food waste processing. This would add an extra 187 megawatts equivalent (MWe) of capacity, powering 285,000 extra homes – representing all the homes in a city the size of Glasgow. Data from WRAP suggests that further food waste collection from businesses would add around a further 10 per cent, depending on the quality of the feedstock collected and what exemptions were applied (for example, it might only apply to businesses collecting more than 50 kilograms per week or the lower threshold of 5kg).

A 38 per cent improvement in food waste collection from flats in Ealing alone could generate £26,000 of annual savings for the London borough, £28,000 in revenue for a local anaerobic digester (based on electricity sales to the national grid) and reductions in carbon dioxide emissions of around 270 tonnes, found Londoners Lab, a collaborative project consisting of Greater London Authority, University College London, Ferrovial Services Centre of Excellence for Cities and Future Cities Catapult.

ADBA has been campaigning on this issue for a while, but the good news is that the government finally signalled its intention to introduce separate food waste collections in its forthcoming Resources & Waste Strategy, which will ensure that all homes and suitable businesses in England will have access to food waste collections by 2023. The next step, following the government announcement, is a consultation, but it is widely acknowledged that additional funding would be needed by local authorities to achieve this, as the business case isn’t currently strong enough.