Scientists say a multimillion dollar plan announced by the Australian government intended to stop the deterioration of the Great Barrier Reef will be ineffectual because it doesn't address climate change, the foremost threat to the natural wonder.

The Reef 2050 Long-Term Sustainability Plan also fails to address coastal development, fishing and water quality, also seen as significant environmental pressures on the reef, Australia's Academy of Science warned.

"The science is clear, the reef is degraded and its condition is worsening," Terry Hughes, a fellow of the academy, said. "This is a plan that won't restore the reef, it won't even maintain it in its already diminished state."

The government's proposed plan for managing and protecting the reef from 2015 through 2050, will be submitted sometime next year to UNESCO's World Heritage Committee, which is threatening to put the Great Barrier Reef on its List of World Heritage in Danger.

Consisting of thousands of connected reef systems, sandbars and island, the Great Barrier Reef spans more than 1,500 miles of Australia's eastern coast off Queensland and is the world's most extensive coral reef ecosystem.

Around 400 species of coral make up the reef, which covers more than 130,000 square miles and is habitat for more than 1,500 distinct species of fish.

A release from the Australian Environment Minister's office said the government's protection plan took into account the "best available science."

"We have a clear plan and a strong commitment to ensure the reef is healthy and resilient -- and we are making strong progress," a spokesman for Minister Greg Hunt said.

But scientists said the plan fails to address ongoing climate change caused by human emission of greenhouse gases, providing "no adequate recognition" of the vital need for curbing such emissions.

The Australian government has announced plans to expand one port on the Queensland coast near the reef to facilitate increased exports of the country's fossil fuels, especially coal, and to construct others.

That would constitute a major threat to the reef's health, Hughes said.

"We need a plan to transition away from fossil fuels well before 2050," he said, calling Australia's announced emissions reduction goals weak by international standards.

"We have stewardship of one of the world's premier reef systems and also stewardship of a huge reserve of fossil fuels -- it's a conflict of interest, really."

He criticized the government for not including more scientists in the creation of the proposed protection plan.

"The government needs to engage with scientists more than they did when putting together this draft plan," he said.