It’s easy to say we’d like our cities to be green. But what does ‘green’ even mean? Of course recycling waste and reducing carbon footprints are important in the pursuit to be eco-friendly, but a sustainable future depends on many more areas.

The Green City Index completed by Siemens – a global leader in engineering and technology services – provides a unique assessment, comparing cities in terms of their environmental performance as a whole. 30 individual indicators are measured touching a wide range of environmental areas, from waste management and greenhouse gas emissions to water consumption and public transport.

Though cities can be assessed on their own green efforts, it’s difficult to compile a definitively ranked list – as each cities faces it’s own issues while working towards their own goals. It is easy however to see which cites are putting in the effort and setting an example for others to follow.

Here are some of the top cities leading by example, detailing a stand out accomplishment that has helped them move towards a more sustainable future:

  • Copenhagen, Denmark
    Working with companies, universities and organisations, Copenhagen has dedicated forums for developing and implementing green growth around the city to reach their carbon neutral goals.
  • Curitiba, Brazil
    Curitiba began its eco-city initiatives long ago, working towards the city’s current total of 52 m² of green space – making it literally the ‘greenest’ city in the world.
  • Oslo, Norway
    Embracing renewable energy early on, Oslo has become a leading city in electric car use – waiving tolls, removing parking fees and allowing access to the city’s dedicated public transport lanes for eco-drivers.
  • San Francisco, United States
    San Francisco’s mix of strict recycling programmes, and pay-as-you-throw on non-recyclable garbage have made it the greenest city in the US – bringing them closer o a zero-waste future in 2020.
  • Stockholm, Sweden
    Introducing a congestion tax in 2007, Stockholm has greatly reduced car use while offering green transport alternatives – with money raised going towards improving the environment.
  • Singapore City, Singapore
    Singapore’s Green Mark Scheme ensures all buildings are green through-and-through – incorporating green building requirements into legislation.
  • Vancouver, Canada
    In 2011 Vancouver launched its Greenest City Action Plan, focusing on reducing emissions and waste, while increasing a green economy. The city has recently set a new goal of becoming a completely renewable city by 2050.
  • Vienna, Austria
    Vienna shines when it comes to water efficiency – water is harmlessly collected and used to generate electricity. Any wastewater from the city is treated and purified before being released back to nature.

For more on which cities are doing their part for a brighter future and how, be sure to check out the infographic below.