The Prince of Wales told the Islamic Economic Forum that big businesses need to take more responsibilty for the natural world as it is not a limitless resource.

Financial institutions must take a more responsible approach to the environment as it is “not a limitless resource which can be plundered at will”, the Prince of Wales said last night.

The Prince, who has campaigned vociferously on environmental issues, said that big businesses have a responsibility to act as a “steward” of the world and change the way they operate to minimise their impact on the environment.

He used his keynote speech at the 9th World Islamic Economic Forum in London to warn that financial institutions need to treat “natural capital” with the same importance as financial capital to ease the strain on the planet’s resources.

“It is clear from the Koran, and indeed the Bible too, that humanity has a sacred responsibility for the stewardship of the Earth,” he told the gathering of 1,800 political and business leaders from over 115 countries.

“The time then has surely come for our financial institutions to recognise that the Earth is not a limitless resource that can be plundered at will, and to integrate that principle of stewardship into our financial structures.”

The Prince, a fervent supporter of action on climate change, said the deterioration of “nature’s capital reserves” like water and soils can cause direct impacts on food and energy security.

“We each have a sacred duty of care towards the Earth,” he said. “It calls upon us to shoulder this work together.”

The speech follows similar comments by the Archbishop of Canterbury who last week warned that bankers are ignoring what is morally right because they are focusing solely on whether practices are within the law.

Speaking to business leaders last week the Most Rev Justin said City investors had become focused on a “number on a screen” instead of considering the impact of their decisions on workers.

Failure to manage Earth’s natural resources was a major hidden contributor to the Syrian crisis, the Prince added.

“The tragic conflict in Syria provides a terrifyingly graphic example, where a severe drought for the last seven years has decimated Syria’s rural economy,” he said. “Driving many farmers off their fields and into cities where, already, food was in short supply.

“This depletion of natural capital, inexplicably, little reported in the media, was a significant contributor to the social tension that exploded with such desperate results.”

He said Islamic banking, or alternative banking, could provide the answers where conventional” banking could not, given Islam’s emphasis on the “moral economy”.

The Prince said there was a welcome emphasis in Islamic finance that wider ethical and moral codes could not be separated from business.

Several major Islamic world leaders are attending the two-day event, including King Abdullah of Jordan, the Sultan of Brunei and Afghan President Hamid Karzai.

The Prince met delegates before taking to the lectern and while much of the discussion was on congratulating Charles on the arrival of his grandson Prince George, it primarily focused on the desire to forge business links in the UK.

Prime Minister David Cameron earlier announced the UK hoped to offer a £200 million Islam-friendly bond as early as next year.

Mr Cameron said he wanted London to be “the greatest centre for Islamic finance in the Western world”.