The 2021 City Science Summit was the network’s 5th annual event, bringing together leaders in the fields of urban science, computer science, policy, decision making, and social sciences. The summit theme, Cities WITH(in), challenged the eight City Science Network labs to seek opportunities for their research to impact local solutions to global challenges. The event was a collaboration between the City Science Lab at Taipei Tech and MIT City Science and it allowed for a creative exchange of ideas with participants from around the globe, discussing sustainable urban development, new mobility modes, zero-carbon cities, data-empowerment and collaborative decision making.

The summit theme was echoed in the Main Stage presentations where each network director presented their latest research. Months before the summit, Kent Larson created a City Science framework for the Sustainable Development Goals, offering more detailed and actionable descriptions to the relevant SDGs which can be implemented throughout the network. In their presentations, the network directors each remarked on which SDGs they felt their lab and their research tackled best.

"We will never successfully address climate change without rapidly deploying a new model for cities." -Kent Larson