Certain cities have succeeded in overcoming bureaucracy to become more sustainable living environments. Out of 120 cities studied by Siemens and C40 members, ten in particular have been identified as taking a lead based on criteria including urban transportation, carbon measurement and planning, energy-efficient buildings, air quality, green energy, adaptation, sustainable communities, and waste management.
San Francisco: zero waste programme
The city's zero waste efforts have pushed landfill diversions from 35% in 1990 to 80% in 2010. Last year, the city disposed of 428,048t of material, the lowest level on record. Mandatory recycling and composting increased organics collection by 50% to more than 600t a day, more than any composting programme in the US.
Mexico City: air quality
In 1992, the United Nations named Mexico City the most polluted city on the planet. A series of programmes called ProAire have helped the city curb its once ubiquitous smog, and reduce its carbon emissions by 7.7 million tons between 2008 and 2012. To achieve that, the city implemented aggressive measures including closing its most polluting factories, banning cars one day a week in its metro area and launching the bus rapid transport (BRT) Metrobus system in 2005.
Bogota: urban transportation
The city's rapid transit system, Transmilenio, was launched in 2000 to transport more than 70% of its population and has reduced annual emissions by 350,000t. Now, the city is working to replace the current diesel fleet with hybrid and full electric buses in order to reach 100% conversion by 2024.
Copenhagen: carbon measurement and planning
Copenhagen's 2025 Climate Plan put it on track to become the first carbon-neutral capital city. The plan includes a goal to lower energy consumption in commercial buildings by 20%, households by 10% and public buildings by 40%. Street-lighting will use 50% less energy and by 2025, all of the city's electricity consumption will come from renewable sources.
New York City: adaptation and resilience
Hurricane Sandy in 2012 flooded New York City and paralysed transportation networks. Six months later, the city released its 'A Stronger, More Resilient New York' plan that includes over 250 initiatives to protect the coastline as well as strengthen its buildings and vital systems. The plan is in its first phase, which is focused on resilience of buildings and power infrastructure.
Rio de Janeiro: sustainable communities
A 2010 census revealed that an estimated 22% of Rio's population lives in favelas with inadequate sanitation or building standards. The Morar Carioca project aims to provide integrated development and services, and the government aims to formalise all of its favelas by 2020 to improve living conditions for up to 232,000 households.
Munich: green energy
In 2009, the German city set a goal of achieving a 100% renewable energy supply - at least 7.5 billion kilowatt hours a year - by 2025. The city-owned utility company Stadtwerke München (SWM) has focused on cost-efficient projects that are self-sustaining; water, geothermal, solar biomass and wind power all play a role in SWM's strategy.
Tokyo: finance and economic development
Tokyo launched the world's first urban cap-and-trade programme on 1 April 2010, requiring large commercial, government and industrial buildings to reduce carbon emissions through on-site energy efficiency measures or participation in the emissions trading scheme. Under the programme, Tokyo set the cap at 6% for the first compliance period of fiscal year (FY) 2010 to FY 2014. In its first year, the 1,159 participating facilities reduced emissions by a total of 13%. Reports submitted in November 2012 bring the second-year total to an overall 23% reduction below the base-year (2000) emissions.
Singapore: intelligent city infrastructure
Singapore is faced with a lack of space and a booming urban population, a combination that has made traffic management a challenge. In response, the city-state has implemented an intelligent transport system, along with a number of initiatives including free public transportation during pre-morning peak hours, a vehicle quota system, congestion charges and an extensive public transport network.
Melbourne: energy-efficient built environment
The city government has set a target to reduce carbon emissions from the commercial sector by 25% and from the residential sector by 20%. Melbourne will achieve this through environmental standards governing new buildings as well as financial incentives and advice for upgrading and retrofitting existing buildings. The so-called 1200 Buildings programme was designed to encourage the retrofitting of 1,200 commercial buildings, about 70% of the city's commercial buildings stock.