Australia's big four banks are leading lenders to the massive expansion in coal and gas shipments through the Great Barrier Reef, contradicting their own pledges to curb carbon emissions and preserve sensitive environmental areas, according to activist group Market Forces.

The ANZ, Commonwealth, NAB and Westpac banks have lent almost $4 billion over the past five years to develop the energy projects in the Great Barrier Reef World Heritage Area, with the sum likely to multiply in coming years as new ventures are approved, said Julien Vincent, lead campaigner with Market Forces.

Big dollars: The nation's four leading banks have lent almost $4 billion to develop engery projects in the Great Barrier Reef over the past five years.

''We're effectively killing off the reef in the short term through local environmental impacts by the industrialisation of a world heritage site that enables accelerating global warming'' as the fossil fuels get burnt, Mr Vincent said.

''The science has been showing for years that [climate change] is going to bring about the devastation of coral reefs around the world through ocean acidification and coral bleaching.''