The indirect effects of carbon sequestration approaches in cities might have a bigger impact

Various nature based solutions are being used and proposed for cities to sequester carbon. These solutions include street trees, permeable pavements, urban green spaces and architecture, habitat preservation, and green buildings. Unfortunately, the contribution of these approaches is relatively small. Studies from the European Union show that these approaches can only sequester about 6.5-8% of total emissions (Pan and colleagues, 2023).

However, in a recent article, Pan and colleagues (2023) found that there are large potential indirect effects. For example, narrower roads and street trees can help make walking and cycling more appealing reducing the car dependency in a community. Green buildings can reduce resource use through reduced materials and maintenance. Trees, park areas, and green roofs can reduce the heating and cooling costs for buildings and make it more aesthetic and enjoyable to be outside which can further improve things like willingness to walk and cycle.

The impact of these indirect effects was significant but also pretty variable depending on where the city was, the current design, and how it was implemented. The impacts ranged from a high of 57% to a low of 16%.

This research really highlights how addressing climate change is never going to be about just one thing. There are interconnections everywhere. Designing our cities for cars led to it being harder to get around with anything but a car. Changing how we design our cities to mitigate climate change in one way will have other effects and we need to think about those interconnections so that we can maximize the positives and minimize the negatives. This requires bigger conversations between many different people.