Cities are working to identify sources of transport emissions to establish accurate emission reduction goals, and to define policies that effectively drive sustainable mobility transitions. Assessing climate impact from transportation at the local level is, however, complex. It requires multiple emissions accounting and modelling approaches, each of which rely on a variety of data sources, from fleet composition to fuel efficiency data, distance travelled, and occupancy factors. Transportation emissions by their very nature cross geographic borders, which adds another layer of complexity.

In other words, new approaches and data sources are needed to accelerate decision-making processes in this sector. To this end, ICLEI Europe has worked with Google and nine European cities to explore how one such tool, Google’s Environmental Insights Explorer (EIE), could support cities’ sustainable urban mobility transitions.

EIE is a free tool that provides cities with Transportation and Buildings Emissions, Rooftop Solar Potential, and Tree Canopy data, using Google Maps data, AI, and machine learning modelling techniques. EIE uses anonymised and aggregated data and models to estimate annual vehicle trips by mode (e.g. car vs. bus) and by vehicle distance travelled. Emissions data are then provided, following the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories (GPC) methodology.

Assessing EIE’s potential to help reduce emissions

ICLEI Europe conducted a technical assessment and analysis of EIE’s Transportation Emissions data for nine cities: ICLEI Members Florence (IT), Izmir (TR), Lisbon (PT), Malmö (SE), Mannheim (DE) and Warsaw (PL), as well as the cities of Athens (GR), Greater Manchester (UK) and Madrid (ES). In short, the assessment aimed to compare the emissions data provided and methodologies used by EIE with those already used by cities. These cities report their GHG emissions and climate actions using the CDP-ICLEI Track, a key information source that informed this analysis.

Findings from the analysis differentiate between cities that use ‘top-down’ vs. ‘bottom-up’ emissions calculations. Top-down approaches calculate emissions as a result of total fuel consumed multiplied by a GHG emissions factor for each fuel type; while bottom-up approaches account for more detailed data about transport activity, modal share, fuel efficiency, etc. Overall, the ICLEI analysis found:

• Cities using top-down approaches may find value in using EIE to improve their current calculation methods by leveraging the bottom-up datasets the tool provides.
• For cities using a bottom-up approach, EIE may support validation and improvement of current calculation methods and modelling processes. For example, EIE data can be used to complement, improve, or validate their vehicle kilometres travelled (VKT) estimations.
• Cities using national data sources to estimate on-road transport emissions can benefit from access to EIE data, which offers the potential to develop more accurate bottom-up approaches, or to validate top-down assumptions.

Tools like EIE can support emissions accounting processes and can also help identify low-carbon alternatives for on-road transport, one of the biggest sources of GHG emissions and air pollution in cities. This work should be done together with transport planners and sustainable mobility experts.

Google, ICLEI, and participating cities see value in further analysis – done together with transport planners and sustainable mobility experts – on how tools like EIE can open further opportunities for data-driven climate action.

How cities are using Google’s EIE data

Zooming in on two ICLEI Members in particular – namely Izmir and Warsaw – can help illustrate how cities are currently using EIE data, and its potential more broadly.

The Metropolitan city of Izmir has developed a Sustainable Energy and Climate Action Plan (SECAP), where they committed to reducing CO2 emissions by at least 40% (per capita) against a 2018 baseline by 2030. Yet, with a very populous urban area of over 4 million inhabitants, its growing population represents a challenge to transport planning. Izmir used Google’s EIE data to evaluate their transport emissions calculations, using a top-down fuel consumption based approach.

“Monitoring city data and rapid data collection is very important, hence, Google’s EIE tool is very promising because it can provide cities additional insights to assess the current status of the city and develop a correlated analysis with the cities’ own data. We believe that the tool will provide comprehensive and rapid information to cities working to tackle climate change,” explains Dr. Çağlar Tükel, Engineer from the Izmir Metropolitan Municipality, Directorate of Climate Change and Clean Energy.

The City of Warsaw is currently establishing long-term emissions scenarios for 2030 and 2050, and has developed a Green City and Climate Action Plan (GCCAP) that outlines environmental, low-carbon and climate resilience development pathways for the city.

The city sees EIE’s data as a complementary data source that can supplement their top-down approach to calculating emissions from public and private transport. The city is planning to use EIE to validate assumptions in its calculation processes – which are now based on internal transport modelling techniques.

Marcin Grądzki, Head of Climate Policy Unit, City of Warsaw explains: “Since resources allocated to climate change in cities are sometimes very limited, any help or assistance in creating and analysing data is not only very welcome but also necessary. I believe that tools like Google’s EIE can jump in on these processes and be extremely helpful.”

The future of sustainable, data-driven mobility transitions

Our analysis found that Google’s Environmental Insights Explorer is a promising tool that can support cities’ ambitions to reduce emissions and promote sustainable urban mobility. EIE’s ability to provide granular, year-by-year and mode-specific data opens new opportunities for cities to pursue data-driven mobility policy.

Climate action is urgent. Cities must consider new data sources, like EIE, to be able to effectively accelerate action. And it is important for tools like EIE to continue to engage the larger community of transport planners and sustainable mobility experts, to help promote collective action for sustainable cities.

For more information, read the full Technical Report and the Overview for Policy Makers. EIE recently released its 2022 Transportation Emissions data, including data between 2018 and 2022. Read their blog post to know more about the versatility of the data. To learn more about EIE, visit their website, sign up for access by emailing urbandata-europe@iclei.org, or fill out this form to stay informed about EIE updates.