Mayors to 'lead by example' on climate change

The conference was held a day after the US's National Oceanic and Atmospheric Administration reported that 2015 had the hottest first six months in 135 years.

The text was signed at a meeting on climate change and human trafficking, held at the Vatican.

The declaration, which has not yet been made public, but which was seen by this website, said “cities play a very vital role” in fighting climate change.

It called for a “bold climate agreement that confines global warming to a limit safe for humanity, while protecting the poor and the vulnerable from ongoing climate change that gravely endangers their lives”.

The mayors said the world should move away from fossil fuels and toward renewable energy, while taking a stab at those that deny humans have caused climate change.

“Human-induced climate change is a scientific reality, and its effective control is a moral imperative for humanity”, it added.

Pope Francis recently took up the fight against climate change as one of his core issues, writing a provocative document in which he called on people to change their lifestyle.

The leader of the Catholic church links climate change to poverty, arguing that the world's poor are the most effected by global warming,despite being the least responsible for it.

This was also reflected in the mayors' declaration.

“The high-income countries should help to finance the costs of climate-change mitigation in low-income countries as the high-income countries have promised to do”, the text says.

A Vatican booklet published ahead of the meeting noted that “global warming is one of the causes of poverty and forced migrations, and it favours human trafficking, forced labour, prostitution and organ trafficking”.

The list of participants to the Vatican conference included 64 mayors and other local leaders, 11 of them from Italian cities, and another 10 from other European cities, including the mayors of Paris, Stockholm, Madrid, and Berlin's deputy minister for environment.

In recent years, many mayors have adopted environmental policies which go further than their national governments.

Paris, London, Amsterdam, and Brussels are among cities where mayors are pushing for low-emission zones.

“As cities, we can lead the way in demonstrating innovative solutions. We can fight against climate change”, Karin Wanngard, the mayor of Stockholm, said at the Vatican conference.

“Climate negotiators must dare to push boundaries and exclude fossil fuels as an option, and to reward solutions for fuels, energy, and building material that are long-term, sustainable and recyclable”, she added.

The mayor of Bristol, in the UK, George Ferguson said that to convince citizens to change their behaviour, local politicians should “lead by example”, adding that he has sold his car.

“You can't do it simply by lecturing to them, you have to involve them”, said Ferguson.