Is your city green? It can be hard to tell, says Tim Sorrell, head of the UK’s Commission for Architecture and the Built Environment. He says it is not only time to think green, but that it is time for a radical reimagining of what a city should be.

Sorrell proposes certain benchmarks that indicate how green a city is:

1. Does the city economically encourage green building and renovation? This is important as an indicator because it shows whether the municipality is making the clearest commitment- financial- to assisting citizens to change.

2. Are there realistic transit options besides cars? With proper planning, transit systems are one way to tremendously shrink a carbon footprint. Sorrell explains that even suburbs that plan transit systems can reduce or eliminate the need for cars.

3. Is the city increasing the number of plants and trees? Sorrell says that greenery is important not only to combat the heat trapping effects of the city, but also to provide a visual expression of the city’s efforts.

Finally Sorrell points to another critical factor important to any green city: its’ peoples’ understanding that their welfare is intimately tied to the cities' welfare. Without personal investment, the “civic leadership” necessary to institute change will not emerge.

Read more at the BBC.