UN secretary general says wise energy investment and strong civil society movements, such as the divestment campaign, are vital for a strong climate change agreement at the Paris summit.

The world’s governments and businesses need to choose wisely and invest in low carbon energy, not the dirty fossil fuels of the past, according to the UN secretary general Ban Ki-moon.

He said that climate change was striking faster than expected, but that the transition to clean energy was also accelerating.

In an interview with a British newspaper, Ban said previous slow progress on tackling climate change had spawned strong civil society movements, including a fast-growing fossil fuel divestment campaign. He encouraged citizens to press for action on global warming, which he said was a vital component of sealing a strong climate change deal at a crunch summit in Paris in December.

Ban also said, with a papal encyclical on climate change due to be published in June, that he welcomed the addition of Pope Francis’s moral voice to the debate. Ban stressed that the reduction of poverty around the world was inextricably linked to tackling climate change.

“I have taken the climate change issue as one of my top priorities since I took over my job in January 2007,” said Ban. “This is a defining issue of our time.”

“I have been urging all sectors of society to choose wisely and invest in the low carbon pathway,” he said. “Over the next 15 years, the world will make a massive investment in new infrastructures, in serious renewable energy. We can invest in the low carbon economy or we can invest in dirty technologies.”

“Climate change is happening much much faster than expected,” said Ban. But he said the transition to renewable energy was speeding up also, as businesses became increasingly aware of the advances in technology and falling costs. “We will see a much quicker pace of investment pattern changes,” he said. Last week, insurance giant Axa announced it was pulling €500m from the coal sector and putting €3bn into green investments.

Ban confirmed that Pope Francis, who he met last week, will speak at a UN meeting in New York in September. Ban added: “I’m looking forward to the Pope’s encyclical on the subject, which would add some moral voice on this issue.”

The branch of the UN tasked with delivering a climate deal in December has already added its “moral voice” to the fossil fuel divestment campaign, which is persuading investors from major financial institutions, charitable foundations, universities and churches to dump their fossil fuel investments.

Ban said he was in agreement with the Pope that “ending poverty, embracing human dignity and addressing climate change are interlinked”. Ban said: “Climate change and sustainable development, they are the two sides of one coin.”

Ban said he was optimistic that the world’s governments would reach a climate agreement in December. “There is a strong sense by world leaders from governments and business and civil society that this is the time to reach an agreement,” he said. “There are still some significant hurdles to be overcome. However, all the countries ... believe that they should do it and they can do it.”

“At this time, what is most required is political will by the world leaders of the governments and political will and wise investment by the business communities and also a strong support and engagement of civil society,” he said. “I encourage citizens to press for climate action using peaceful and democratic means.”

The UN climate negotiations resumed in Bonn this week, with officials attempting to pare down a draft text less than six months to go until the Paris summit.

Source: The Guardian