Simply put, cities are the primary source of global emissions. Over 70% of greenhouse gas (GHG) emissions emanate from cities. For this reason reducing urban emissions is an urgent priority in the effort to contain the rise in global temperatures.
Resources and materials flow through and are “metabolised” by cities as goods and services are produced. Resources enter cities as raw materials or components and leave cities as waste in some form or other, including as CO2 emissions.
The built environment is a huge consumer of materials and resources. The built environment is created using materials that generally have high GHG footprints. We urgently need to find new ways of creating low carbon urban environments in ways that don’t squander resources needed for future generations.
It is increasingly understood that the climate crisis needs to be solved in cities. Cities need to be rethought. During the 20th century, the growth of cities was bound up with the ready availability of fossil fuels, mainly oil. Cheap oil enabled cities to expand horizontally in the form of urban sprawl. It enabled easy access to work, schools, medical care, and other services. Sprawling cities use energy wastefully and is no longer sustainable. Our cities are going to need to become more integrated and will need to work at a smaller scale. Densities will need to increase placing pressure on existing infrastructure. We need to be able to access our all the things we need without making long journeys. New modes (or rather quite ancient ones) of transport will dictate the structure. This has given rise to notions of the 15-minute city, where all our requirements can be accessed by walking or riding within 15 minutes. More walking will bring with it better health.
Simon Ratcliffe examines some of the key changes cities can make in order to become the solution to the climate crisis. This publication forms part of our Cities Work service offer.