Cities and climate change

Working together to beat climate change

Climate change is the most pressing environmental, social and economic problem facing the planet. The consequences of climate change are global and long-term.

What is climate change?

Climate change refers to sustained changes in the earth’s climate – including temperature, precipitation, wind and weather patterns. Global warming refers to the rise in the average temperature on the Earth’s surface.

Carbon dioxide levels are higher than at any time in the past 650,000 years. This is caused by human activities such as the burning of fossil fuels (oil, gas and coal).

Other human actions driving climate change include the destruction of forests that naturally remove carbon dioxide and other polluting gases from the air.

The ten warmest years on record have all occurred since 1990. Without coordinated and immediate action across the globe, the earth’s climate will reach a critical 'tipping point' beyond which really dangerous climate change will become unstoppable.

What is the relationship between climate change and cities?

Home to half the world’s population and growing rapidly, cities consume over two-thirds of the world’s energy and account for more than 70 percent of global CO2 emissions.

As a major part of the problem of climate change cities must be a key part of its solution. Cities can do this by:

• increasing the energy efficiency of their infrastructure such as buildings, outdoor lighting, and transportation systems
• using resources more effectively for example through advanced waste management
• producing clean energy at the district-level as well as sourcing clean energy from large-scale suppliers

How are cities affected by climate change?

The effects of climate change will be keenly felt in cities. Many of the world's major cities are at risk of flooding from rising sea levels. Heat-trapping urban landscapes (buildings and paved surfaces) can raise temperatures – and lower air quality -- dangerously through the Urban Heat Island effect. In cities of the developing world, one out of every three people lives in a slum, making them particularly vulnerable to the health and environmental risks posed by climate change.

The good news is that cities are uniquely equipped to deal with the challenges they face. As centres of cultural, political, and economic leadership, cities can act on climate change, implementing bold steps to reduce greenhouse gas emissions that others may follow.