Former Archbishop of Canterbury Rowan Williams has urged world leaders to "step up to the mark" on climate change, and "secure the future for our children and grandchildren."

Writing for the Guardian, Williams – who has been notably outspoken on the issue in the past – insisted that arguments against human involvement in climate change now look "pretty unpersuasive".

A seven-year study from the Intergovernmental Panel on Climate Change reveals that experts are "95% certain that human activity is a significant and avoidable element in driving climate change around the world," the Christian Aid chair explained.

Speaking ahead of the Climate Summit 2014 to be held in New York later this month, Williams urged governments – particularly wealthy industrialised nations – to "act and secure a safe world for today's poorest and tomorrow's children".

"It is those suffering the most who carry the least historic responsibility for our situation," he added.

"With actors who have traditionally dragged their feet taking the lead, and with the urgency for action in developing nations beyond any serious doubt, it is now those who have traditionally been more proactive – European nations in particular – who need to step up to the mark."

Williams praised "encouraging signs" of efforts made by the Chinese government to reduce air pollution, as well as solid action taken by President Obama.

The American leader has backed legislation that will limit carbon pollution from US power plants by 30 per cent by the year 2030.

The rules, announced by the Environmental Protection Agency in June, signify the first time a US president has initiated a move to reduce carbon emissions from power plants specifically. Obama's legislation has therefore been welcomed by climate advocacy groups.

Williams also turned his attention to UK Prime Minister David Cameron, who promised to tackle climate change head on in his last election manifesto.

"David Cameron became prime minister on the promise of 'Vote blue, go green'. He promised to lead the 'greenest government ever'," Williams said.

"His presence and actions at this month's summit will be a significant test of these commitments and aspirations."

Williams concluded his article with a call to prophetic leadership; urging world leaders and politicians to "break free of the tight cycle of calculated electoral advantage – a calculation that often misses the issues that most directly affect everyone's wellbeing."

"The climate summit in New York offers the perfect opportunity for our leaders to show that there is indeed a sensitivity to the kind of prophetic vision that rouses us from complacency, and a will to secure the future of our children and grandchildren."

Mark Letcher, Vice Chair of Christian charity Operation Noah, has welcomed Williams' remarks.

"We welcome these words of hope and echo Rowan Williams' call for climate action," he said.

"The scientific and financial case for action on climate change is clear; we urge the Church to back a global climate deal in 2015 by providing moral leadership."