Environmentalists' plan to confront world leaders with a digital billboard highlighting climate change has been thwarted by Brisbane airport authorities who deemed the message too political.

Brisbane Airport will be the Australian gateway for leaders of 20 economies when they gather in the Queensland state capital next week for the annual G20 summit.

Dermot O'Gorman, chief executive of the World Wildlife Fund, said on Monday he was surprised that operator Brisbane Airport Corp. had refused to allow the climate change message in the international arrivals hall.

Airport spokeswoman Leonie Vandeven says its policy is to refuse advertising that "has political intent."