Greenhouse gas emissions have already peaked in 30 major cities.

• Author: Hutt, Rosamund

Byline: Rosamond Hutt

Greenhouse gas emissions have already peaked, and are continuing to fall, in 30 major cities including New York, London and Paris.

Austin, Athens, Lisbon and Venice are the latest places to hit that milestone in the fight against climate change, according to analysis from C40, a coalition of 94 large and influential cities around the world working to limit global warming and protect the environment.

Cities are home to growing numbers of people. By 2050, 68% of the world's population will live in urban areas, up from 55% today. Cities consume 78% of the world's energy and produce more than 60% of greenhouse gas emissions. That means they have a critical role to play in helping the world to limit dangerous climate change.

But, almost four years after nearly 200 countries signed the Paris Agreement, the world is still seriously off-track from meeting its goals. Global emissions hit a record high in 2018.

Green leaders

The good news is that many cities are stepping up efforts to address the climate crisis.

To keep the increase in Earth's temperature to 1.5AdegC above pre-industrial levels, the Intergovernmental Panel on Climate Change (IPCC) has calculated that emissions must peak by 2020.

Nearly one-third of all C40 cities have already hit that target, with more projected to reach peak emissions by 2020.

And since reaching that marker, those 30 cities, which together are home to more than 58 million people, have gone on to cut their emissions by an average of 22%.

Emissions in San Francisco, California, peaked in 2000 and have been declining steadily since. The city has committed to achieving 100% renewable energy by 2030, and today 77% of its electricity supply comes from greenhouse-gas-free sources.

Emissions in San Francisco have fallen in cities since the...