The world's richest environment prize, the Zayed Prize, has been accepted by the BBC at a ceremony in Dubai.
Sian Kevill receives the prize on behalf of the BBC
The $0.5m award recognises the BBC for its coverage of issues related to the environment and sustainable development.
The judges said the corporation's TV, radio and internet journalism had put policymakers on the spot, forcing them to justify their positions.
The prize was started to honour the president of the United Arab Emirates, Sheikh Zayed Bin-Sultan Al Nahyan.
He is well known for his efforts to try to green the UAE through irrigation, desalination and tree-planting, and for attempting to protect a number of the region's endangered species.
The prize was accepted on behalf of the BBC by Sian Kevill, the editorial director of BBC World, the corporation's commercially funded 24-hour international news channel.
Two other prizes worth $300,000 each went to the founders of the UN-led Intergovernmental Panel on Climate Change (IPCC) and two leading environmental activists.
The IPCC is the body that has assessed the science behind global warming for world governments.
This is only the second time the Zayed Prize has been awarded.
The first award ceremony in 2001 honoured the former US President Jimmy Carter for his work on poverty reduction and the environment.
The chairman of the judges for this year's prize was Klaus Toepfer, the executive director of the United Nations Environment Programme (Unep).
He singled out programmes such as Earth Report and HardTalk on BBC World for special praise, and paid tribute to David Attenborough's many wildlife series for the corporation.
"This broadcaster has year in and year out covered some of the most pressing environmental and sustainable development issues across the full range of its output," he said.
"The BBC's reach, not only via television and radio but increasingly through its online internet service, is matched by its commitment to (42) languages."
The Unep official said BBC programmes had frequently pushed politicians to reverse poorly thought out policies.
"Rarely with the BBC are you allowed to duck the question or ignore the real issues," he said.
'Pat on the back'
Sian Kevill said: "It was a fantastic surprise, we're really glad to have got the pat on the back and the recognition that our coverage deserves.
"But equally it was a surprise that it came from Dubai; you know a country built on oil revenues but when you get here you find that there is a massive number of environmentally friendly initiatives under way."
The BBC executive was handed the winner's trophy by the patron of the Zayed Prize,
Sheikh Mohamed bin Rashid Al Maktoum, the Crown Prince of Dubai.
He said: "Of course we all care about the environment and we know what's happening around the world now and we recognise these people who did something about it and award them."
The prize-giving ceremony came at the end of the 3rd Dubai International Conference on Atmospheric Pollution, which ran parallel with the International Exhibition on Environmental Technology, ENVIROTEX2004.