How can cities around the world reduce their emissions?

  • Cities account for more than 70% of global CO2 emissions. Investing in low-carbon and resilient urban development will therefore be key to reducing emissions.
  • The Glasgow Pact, the outcome of COP26 in November, highlights the need for much deeper emissions reductions and the role cities will play in achieving them.
  • We need to deepen our understanding and our ability to more accurately monitor the efforts of countries and cities to reduce emissions.

COP26 may be in our rearview mirror, but the reality it highlighted is not.

The Glasgow Pact, emerging from November’s climate meetings, stresses the need for much deeper emissions cuts, noting that without major decarbonisation efforts, the world will cross the 1.5°C mark global warming threshold and risk of catastrophic impacts on populations and ecosystems.

The outcomes of COP26 provide a crucial opportunity to reflect on the role cities play in contributing to greenhouse gas (GHG) emissions. Identifying the sources of these emissions, as well as ways to accurately measure and monitor them, is a first step towards significantly reducing them.

Investing in low-carbon and resilient urban development will be key to reducing the city’s emissions and addressing climate change

Cities account for more than 70% of global CO2 emissions, most of which come from industrial and motorized transport systems that use huge amounts of fossil fuels and rely on extensive infrastructure built with carbon-intensive materials. Clearly, staying below the 1.5°C threshold means massive decarbonization of cities, which will require investments in low-carbon energy and transport systems, sprawl reduction programs urban and nature-based solutions for district cooling and disaster risk management. To this end, the World Bank’s latest Climate Change Action Plan (2021-2025) recognizes urban systems as one of five key systems that generate the most GHG emissions and face significant adaptation challenges.

Assessing decarbonization progress requires new metrics because not all cities are the same

Rapid decarbonization will need to be promoted or rewarded with emissions-based performance ratings that make city governments and businesses more accountable to their stakeholders. However, effective performance measures cannot ignore the effects of different demographic, economic and geographic conditions on actual CO2 levels in cities.

Many older cities have inherited carbon-intensive infrastructure. Cities with more populations have more emissions, while cities with higher incomes have fewer emissions-intensive heavy industries. High-income cities have higher land costs and stricter pollution regulations; and cities in particularly cold or hot climates produce more emissions from energy for heating or cooling. Decarbonization by different cities must be assessed against criteria that account for these innate differences.

New metrics will require more accurate and objective CO2 measurements

Assessing the city’s progress in reducing emissions has been hampered by the near absence of directly measured CO2 emissions data. Consistently measured emissions estimates are only available for about 80 cities, only half of them in developing countries. Additionally, virtually no estimates are based on actual emissions. Most estimates rely on parameters from engineering studies that are applied to survey-based activity measures for transportation, energy production, and manufacturing. They are particularly suspect for developing countries, as many of the measures are calibrated using databases and models from high-income economies.

The advent of satellite-based CO2 measurement has greatly expanded the scope of emissions performance ratings. We demonstrate the potential in a recently published working paper that uses data from NASA’s Orbiting Carbon Observatory (OCO)-2 platform to measure CO2 emissions from more than 1,200 cities in 138 countries, with populations greater than 500,000.

Using satellite data to assess whether a city is underperforming or overperforming in reducing CO2 levels

Our research uses a predictive econometric model that estimates the expected CO2 emissions of cities based on their demographic, economic and geographic characteristics. The first image, below, draws on the results of the article to illustrate the relative contributions of these differences to the CO2 emissions of most cities in the sample. (Graphs are presented at a uniform scale for ease of comparison.) The emissions performance of cities is measured as the difference between their expected emissions, given their previously mentioned innate differences, and their actual emissions as measured by observations. satellites.

More than 50% of countries have established national ambient air quality standards, but we need to do more to protect people and our planet.

At COP26, the World Economic Forum and the Clean Air Fund launched the world’s first private sector initiative to tackle air pollution.

Image: Jane Burston/World Economic Forum

Founding members of the Alliance for Clean Air are committed to measuring and reducing their air pollution emissions, creating healthier communities around the world.

Members of the Alliance for Clean Air:

  • Establish air pollution footprints on nitrogen oxides, sulfur oxides and particulates within 12 months
  • Identify where they are emitted to track human exposure
  • Set ambitious targets and goals to reduce air pollutant emissions, with a clear action plan
  • Act as air quality champions by educating employees, customers and communities about the impact of air pollution. They will also help them reduce their exposure and support them to take action to reduce pollution
  • Use their strengths in innovative ways to accelerate clean air solutions

Also at COP26, a practical guide for businesses on how to measure air pollution across value chains is presented by the Climate and Clean Air Coalition and the Stockholm Environment Institute, in cooperation with IKEA. The guide will help businesses understand their impact on air quality and take the necessary steps to reduce their emissions.

If your company is committed to improving air quality, contact us to express your interest in working with us.

The emissions performance of cities is measured by the difference between their predicted emissions.

Image: World Bank Blogs

As this next image shows, there are large variations in performance within and between regions. In general, city performance exceeds expectations (emissions lower than forecast) in India, Western Europe and the former Comecon countries, while it falls short in China, the rest of East Asia and Pacific, Middle East and North Africa and Sub-Saharan Africa. Africa.

City emissions performance by region*

There are wide variations in performance within and between regions.

Image: World Bank Blogs

Future Directions for Assessing City Performance

World Bank research suggests that satellite CO2 measurements can provide valuable support for analyzing and evaluating the performance of urban emissions. Although the study focused on large cities, the same modeling approach can be used in geographical contexts as varied as large and small cities within regions or countries, regions within countries or areas specific projects.

It is also possible to explore how this data can be developed thanks to a regularly updated open source database which will support more applications of this type. Our hope is that we can deepen our understanding and ability to more accurately monitor the efforts of countries and cities to reduce emissions in order to meet the goals of the Paris Agreement and those set out more recently in Glasgow.

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Melvin B. Baillie