By only measuring and reducing emissions within their borders, cities are missing a crucial piece of the picture. Those with primarily service-based economies may be underestimating their overall contributions to climate change by up to 50 percent.
When we burn fuel by driving cars or using gas stoves, we produce direct or "production-based" emissions. This cause and effect is easy to follow. Indirect emissions, also known as "consumption-based emissions," are not as directly measurable — but they are just as important. These emissions originate outside of city borders from the creation of goods that cities import. For example, when a forest is cleared to grow food consumed in a city, or when limestone is heated to make cement for city sidewalks.
Around half of global emissions are consumption-based, caused by the extraction and processing of resources. Cities, in particular, have become compact consumption centers, frequently running on service economies, with raw material processing and manufacturing relegated to other regions. It comes as no surprise, then, that while cities occupy only 3 percent of the global land surface, they consume 75 percent of global resources and are responsible for 60 to 80 percent of global greenhouse gas emissions.
The full picture: production- and consumption-based approaches
Cities have typically focused on production-based approaches to reducing emissions, largely because these impacts are the most straightforward to measure and present more immediate opportunities to act upon. Cities clearly can influence activities within their borders, such as transportation system planning, emissions standards for vehicles and energy performance benchmarks.
But while a transition to renewable energy, complemented by energy efficiency, is crucial, research by the Ellen MacArthur Foundation and Material Economics concludes that these measures can address only up to 55 percent of emissions: "The remaining 45 percent comes from producing the cars, buildings, clothes, food and other products we use every day."
This being the case, cities have a great responsibility — and opportunity — to measure and reduce urban consumption. Research by C40, Arup and the University of Leeds cautions that urban consumption-based emissions must be cut by at least 50 percent by 2030 in order to maintain the possibility of keeping global temperature rise below 1.5 degrees Celsius.
So what can cities do? In the same way that they can guide local emissions by setting energy performance standards on buildings, there are many opportunities to establish the same kinds of standards for sustainable material consumption.
One example is the city of Fort Collins, Colorado, which recently changed its building code to make impact-resistant roofing shingles a requirement. This will prevent yearly losses due to hailstorms and reduce the need for large volumes of new roofing materials on a frequent basis.
Cities are also responsible for land management and procurement of infrastructure and all of the materials required for city operations. In Amsterdam, for example, land is tendered out to developers based on circular economy criteria.
Perhaps most important, cities can influence local self-sufficiency, circularity and the behavior of people and companies. They can do this by developing a clear vision, facilitating bottom-up action and aligning incentive frameworks with clear goals around consumption. Cities such as Charlotte, North Carolina, and Boulder, Colorado, are taking the lead on developing comprehensive strategies to reduce the environmental impacts of consumption through circularity.
A systemic approach avoids ‘burden shifting’
A systemic approach to tracking both production- and consumption-based emissions is critical in helping cities to avoid "burden shifting" — a phenomenon where negative impacts are not resolved but displaced, either to outside of a major city or even another country.
To give an example, if reducing local emissions creates additional costs for companies in a given city, they might decide to move to a location where costs are lower. While this would seem a positive step towards achieving targets on a local level, in reality overall emissions may not be reduced — only shifted.
While cities occupy only 3 percent of the global land surface, they consume 75 percent of global resources and are responsible for 60-80 percent of global greenhouse gas emissions.
As another example, six cities in the United States are already running on 100 percent renewable energy. While this is a hugely encouraging step towards meaningful climate action, it also means that these cities’ relative share of consumption-based impacts likely will grow with demand for materials for renewable technologies. To address their entire carbon footprint accurately, it will become crucial to integrate consumption-based impacts into their climate action strategies.
These types of systemic effects are crucial to understand and manage. Without a strategy that exerts efforts in the right places, we risk spinning our wheels.
Critical action needed in high-income countries
Discrepancies between demand coming from consumption and the impacts it causes elsewhere are seen not only at the city level, but at the country level too.
High-income regions consume significantly more resources than low-income regions. According to the IRP 2019, in low-income countries, current resource consumption is only 2 tons per person, whereas high-income countries consume more than 13 times this amount, about 27 tons a year.
At the same time as consuming more, high-income countries are producing less. In 1970, North America, Europe, Asia and the Pacific, and the rest of the world each accounted for around a quarter of the primary material extraction and use. Now, Asia and the Pacific accounts for nearly 60 percent (IRP, 2019). The world is increasingly dependent on the material extraction and product processing that takes place in these regions, yet failing to account for the resulting emissions.
In order to prevent devastating levels of damage from climate change, we need to reduce global per-capita carbon footprint to 5.8 tons/person this year, and down to 2.1 in just 30 years. Most developed countries have per-capita footprints many times this amount — consider that the average American diet alone results in around 2.5 tons of CO2 emissions per year or that a round trip flight from Amsterdam to Los Angeles results in 2.8 tons of CO2 per passenger.
Discrepancies between demand coming from consumption and the impacts it causes elsewhere are seen not only at the city level, but at the country level.
While some European countries are close to 2020 targets for direct emissions, they still have a net import of more than 4 tons of CO2e per person on top of that, resulting from the consumption of products produced elsewhere. That means that even if Europe manages to reach the target within its own borders, its citizens still technically would be causing nearly twice that amount of greenhouse gas emissions, through consumption choices and trade.
Management starts with measurement
While transparency on local consumption levels is a challenge, and there is a lot of complexity in evaluating the impacts of imported goods, productive steps are being made to simplify consumption-based emissions assessment.
ICLEI offers a technical assistance program to help local governments with consumption-based accounting, and the C40 Cities Climate Leadership Group has piloted a consumption-based emissions methodology with 79 cities across the globe. In our work at Metabolic, we have helped cities such as Boulder take steps towards a consumption-based emissions approach, and on a regional level, worked with the Swiss Federal Office for the Environment to build capacity around consumption-based footprinting approaches.
With increasing progress, a broader paradigm shift is taking place. Cities, countries, individuals and companies are starting to understand their part in the bigger picture.
Cities will need to start acting on impacts beyond their own borders if they hope to address the global environmental challenges we are facing. A combination of production-based and consumption-based impact assessments will arm cities with an accurate starting point for developing robust climate action strategies.
The cherry on top? The strategies that cities implement to address these systemic issues can also lead to systemic benefits that strengthen resilience and innovation within their own communities.