If Cities Are Going to Curb Their Carbon Emissions, They Have to Consider Consumption

CC BY 2.0. New York City from Governor's Island/ Lloyd Alter

It's not just about how we build and how we get around; it's also what we eat and wear and buy.

It is a standard trope of urbanists that cities are the most sustainable places to live. After David Owen wrote the Green Metropolis I noted that "New Yorkers use less energy and create less greenhouse gases than anyone else in America; that is because they tend to live in smaller spaces with shared walls, have less room to buy and keep stuff, often don't own cars (or if they do, use them a lot less) and walk a lot."

Future of urban consumption

© C40 Cities

But a study released earlier this year suggests that we are underestimating the carbon impact of our cities. When your average New Yorker buys a steak or a new shirt, that has an impact too. The report, The Future of Urban Consumption in a 1.5°C World, was released by Arup, C40 Cites and the University of Leeds. I alluded to it in an earlier post on upfront carbon emissions. But recently, I have been revisiting studies on how we get ready for a 1.5 degree lifestyle and achieve sustainable outcomes, and I missed its significance.

The report notes that many cities have done a good job at reducing local emissions. But, as many complained a decade ago about David Owen's thesis about New Yorkers being green, urban dwellers consume a great deal of stuff from beyond their boundaries.

When a product or service is bought by an urban consumer in a C40 city, resource extraction, manufacturing and transportation have already generated emissions along every link of a global supply chain. Together these consumption-based emissions add up to a total climate impact that is approximately 60% higher than production-based emissions.

So it's not enough to just cut direct emissions, we also have to cut the footprint of all the stuff that we consume. Then the picture changed dramatically:

Cities and urban consumers have a huge impact on emissions beyond their own borders since 85% of the emissions associated with goods and services consumed in C40 cities are generated outside the city; 60% in their own country and 25% from abroad.
Different sectors

© C40 Cities

If we are going to stay within the greenhouse gas budgets and hold the temperature rise to 1.5°C, the report says we have to cut emissions by 50 percent by 2030 and 80 percent by 2050. And that's not just the emissions from cars and buildings, but also all the things that we consume in that city, from red meat to cars to blue jeans to electronics to leaving on a jet plane.

Buildings and Infrastructure (11 percent of total emissions in C40 cities in 2017)

Consumption interventions for buildings and infrastructure and associated targets.

© Consumption interventions for buildings and infrastructure and associated targets.

The biggest source of emissions is a usual suspect – buildings and infrastructure. Here, the first thing to do is use less steel and concrete, substituting lower carbon materials and just building less. This will be no surprise to TreeHugger regulars.

Food (13 percent)

Changes required in food

© C40 Cities

But the most surprising finding in this report is that food, at 13 percent of emissions, actually has a bigger carbon impact in cities than cars. So we have to cut waste, eat less meat and dairy (preferably none), and even limit calories. I suspect that this will be a hard sell.

Private Transport (8 percent)

private transport

© C40 Cities

Since we are also looking at the emissions from making things as well as using them, the upfront emissions of building cars matters, totally a third of their total emissions. So we need to cut the numbers significantly (ambitiously, to zero), make them last longer, and reduce their weight by half, which could be done easily by banning SUVs and light trucks for non-commercial uses. Surprisingly the report doesn't mention what we do instead; I assume walking or biking.

Clothing and Textiles (4 percent)


© C40 Cities

It's surprising what an impact clothing and textiles have, 4 percent of total emissions. It's twice as high as aviation. So no more big shopping sprees for fast fashion; ambitiously, no more than three new items per year. Look for a boom in Value Village and other used clothing stores.

Electronics and appliances (3 percent)


© C40 Cities

Appliances and electronics are going in different directions; most computers can easily last seven years now (my last MacBook is still going strong at 7) but appliances are not lasting nearly as long as they used to. I just replaced a stove after four years because the electronics kept blowing out and it was costing more to fix them than it was to replace the stove. That's just wrong. Seven years is a minimum!

Aviation (2 percent)


© C40 Cities

No more flying to conferences for me. I do not understand why it allows any short haul flights; the answer should be zero, take the train. It's the long-haul flights that are the real difficult problem to solve.

Many will roll their eyes over all this, questioning whether personal consumption by individuals belongs in a discussion of cities. I can already imagine the comments, taking away our freedom to buy new pants. I have been told more than once recently that I shouldn't be focusing on individual consumption, it's the big corporations that are causing the problems. But they are making stuff that we consume. It involves all of us.

Reducing consumption-based emissions will require significant behavioural changes. Individual consumers cannot change the way the global economy operates on their own, but many of the consumption interventions proposed in this report rely on individual action. It is ultimately up to individuals to decide what type of food to eat and how to manage their shopping to avoid household food waste. It is also largely up to individuals to decide how many new items of clothing to buy, whether they should own and drive a private car, or how many personal flights to catch every year. As this report shows, these are some of the most impactful consumption interventions that can be taken to reduce consumption-based emissions in C40 cities.

But given that our consumption is responsible for as much as 85 percent of emissions in our cities, we cannot ignore it. Our personal choices matter more than we ever knew.

The potential influence of city climate action extends far beyond municipal limits. Focusing on consumption-based emissions enables a city to consider the positive impact it can have on emission reductions within and beyond its borders to help bring about a global transition to clean production. Individuals, businesses and governments in C40 cities have significant spending power, which means they can affect what and how goods and services are bought, sold, used, shared and re-used.

If we are going to reduce our emissions enough to keep the temperature rise below 1.5 degrees, it is going to take all of us living the 1.5 degree lifestyle.