SYDNEY, Nov 29 (AFP) - Australia's Great Barrier Reef should be listed as a world heritage site that is "in danger", a UN panel recommended on Tuesday, saying the world's biggest coral reef ecosystem was significantly impacted by climate change and warming of oceans.

Frequent bleaching events are threatening the reef, including four over the last seven years and the first during a La Nina phenomenon, which typically brings cooler temperatures, this year.

Bleaching happens when the water warms too much, causing corals to expel the colourful algae living in their tissues and turn white.

"The resilience of the (reef) to recover from climate change impacts is substantially compromised," a report by the United Nations Educational, Scientific and Cultural Organization (UNESCO) scientists, who visited the reef in March, said.

Environment Minister Tanya Plibersek said the government would push UNESCO to not list the reef as endangered because climate change was threatening all coral reefs across the world.

"We'll clearly make the point to UNESCO that there is no need to single the Great Barrier Reef out in this way," Plibersek said during a media briefing.

"The reason that UNESCO in the past has singled out a place as at risk is because they wanted to see greater government investment or greater government action and since the change of government, both of those things have happened."

Australia's recently elected Labor government has pledged to spend A$1.2 billion ($800 million) in coming years to protect the reef. The parliament in September passed a legislation for net zero emissions by 2050.

Canberra has lobbied for years to keep the reef - which contributes A$6.4 billion ($4.3 billion) to the economy - off the endangered list as it could lead to losing the heritage status, taking some shine off its attraction for tourists.

Last year, Australia dodged an "in danger" listing for the reef after heavy lobbying by the previous government led UNESCO to postpone a decision to this year.