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 is how the average weather of our planet varies over time. The average temperature on the Earth’s surface is rising. This is called global warming.

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 factors affecting climate change include the destruction of forests (deforestation). Forests are important as they help to naturally remove carbon dioxide and other polluting gases from the air.

The ten warmest years on record have all occurred since 1990. If we do not stand together and act now to tackle climate change, the world will reach a critical 'tipping point' beyond which really dangerous climate change will become unstoppable.

We must take steps now to try and prevent further climate change rather than mitigate its effects later – when it is already too late.

What is the relationship between climate change and cities?

Cities cover less than one per cent of the earth's surface but are disproportionately responsible for causing climate change.

Currently, around 50 per cent of the world’s population live in cities (set to reach 60 per cent by 2030). Yet cities consume some 75 per cent of the world’s energy and are responsible for 80 per cent of greenhouse gas emissions.

So a majority of the world's energy consumption either occurs in cities or as a direct result of the way that cities function (eg through transport of goods to points of consumption in cities).

Cities bear a large responsibility for causing climate change and are therefore key to alleviating climate change. We have to move from a high energy-use, wasteful economic model to one that conserves energy and minimises waste. In other words we have to be more efficient.

How are cities affected by climate change?

The effects of climate change are often more keenly felt in cities, eg the Urban Heat Island effect. Since many of the world's major cities are very close to the sea, rising sea levels are a major threat.

The concentration of resources in cities can be a useful weapon in fighting climate change. Cities are often centres of new thinking and policy innovation – cities are in a great position to lead the way for others to follow. Novel approaches can be developed that if successful can be rolled out to other cities.