World cities can mandate policies with the goal of lowering greenhouse gases (GHGs) in order to fight climate change. Cities can pass ambitious climate laws in order to meet the nationally determined contributions (NDCs) made at the Paris Climate Accord. The cities listed below accomplish this by implementing policies that mandate lower GHG emissions, policies prioritizing the implementation of clean and efficient energy technologies; and sustainability priorities like conservation.

Here are examples of world cities taking the lead on climate:

Paris - Curbing Auto Emissions for Cleaner Air

Crit'Air in Paris is one of the largest pioneering programs in a major world city to mandate compliance with emission standards for vehicles (in this case, European emissions standards). After successful implementation in Paris, Crit'Air policies now cover about 28 permanent zones in France, and also weather-dependent zones in France...

France's efforts in reducing GHGs with legislative mandates to curb auto emissions are only part of France's sustainability ambitions. Another legislative advancement that France has made (in 2016) is to tackle the problem of food waste; by mandating that supermarkets donate unsold food items to charity.

Please read:

greencitytimes.blogspot.com/france-implements-policy-to-tackle-food-waste

Olso - Climate Goals: Is Oslo Leading the Way?

Oslo, Norway leads the world in EV adoption, thanks to strong citywide policies that encourage zero emission vehicles. This is one of many ways Oslo is leading the world in the race toward net zero emissions.

Green City: Portland

Portland leads the US in the rate of recycling, alternative sustainable transit, and is invested in green urban planning.

San Diego - Profiles in Sustainable Cities

(please also see the Green City Times article on Desalination for information about the largest desalination plant in the Western Hemisphere; in Carlsbad, San Diego)

New York City - The Clean Path NY plan is an $11 billion sustainable infrastructure project. After builders conduct the structural alterations, New York City will gain access to 7.5 million megawatt-hours (MW) of renewable energy annually.

Chicago - A Sustainable City

Public mass transit options in Chicago include subways, a large network of buses, commuter and light rail trains, and 'L' cars (above-ground rail cars running on the elevated subway line). CTA has a goal to use 100% clean energy by 2040.

The greater Chicago area consists of 12,429 total acres of parkland (including land managed by the state and county, with 8,100 acres of parkland managed by the city). 8.5% of the land area of Chicago is park space open to the public.

Austin, Texas

Community solar is one example of how Austin is leading American cities, and worldwide, in renewable energy.

And, here are the rankings for Green City Times top 10 greenest cities in the world>>>

The TOP 10 greenest cities in the world (as determined by Green City Times):

1. Reykjavik, Iceland  
2. Vaxjo, Sweden  
3. Freiburg, Germany 
4. Vancouver, Canada  
5. Copenhagen, Denmark  
6. London, UK 
7. Curitiba, Brazil 
8. Portland, Oregon, US 
9. San Diego, California, US 
10. Oslo, Norway