As many focused this week on the United Nations, where world leaders debated how to meet the predicted effects of global climate change, President Obama created the largest marine reserve in the world.

By signing a proclamation Sept. 25, the president expanded the Pacific Remote Islands Marine National Monument, which was created by President George W. Bush in 2009 and centered on seven islands and atolls the United States administers in the central Pacific Ocean, according to a White House press release.

As initially established, each island or atoll was protected out to a distance of 50 nautical miles, giving the monument an area of 83,000 square miles.

Obama's action, issued under the 1906 Antiquities Act which allows a president to set aside structures or objects of historic or scientific interest on federal lands for preservation, extended the reach of the monument to six times its current size, resulting in 370,000 square nautical miles, or nearly half a million square miles, of protected area around the included tropical islands and atolls in the south-central Pacific Ocean, the release also said.

The move will more fully protect seamounts and marine ecosystems that are unique to that part of the world and which are among the most vulnerable areas to the impacts of climate change and ocean acidification.

"The Monument is an important part of the most widespread collection of marine- and terrestrial-life protected areas on the planet, sustaining many endemic species including corals, fish, shellfish, marine mammals, seabirds, water birds, land birds, insects, and vegetation not found elsewhere," Obama said in the proclamation. "The ecosystem of the Monument and adjacent areas also is part of the larger Pacific ecosystem. The Monument land and atoll groups and the adjacent areas share geographic isolation, as well as climate, bathymetric, geologic, and wildlife characteristics that define them as individual biogeographic regions. However, the Pacific Remote Islands area, including the adjacent areas, is tied together by regional oceanographic currents that drive marine species larval transport and adult migrations that shape the broader Pacific ecosystem."

While the recently released National Climate Assessment asserts that climate change is causing sea levels and ocean temperatures to rise, Obama announced his commitment to use his authority to protect some of the nation's "most precious marine landscape just like he has for our mountains, rivers, and forests," a statement read. "the Administration examined how to expand protections near the Monument and considered the input of fishermen, scientists, conservation experts, elected officials, and other stakeholders, including through a town hall meeting and over 170,000 comments submitted electronically."

Under the new proclamation, commercial fishing and other resource extraction activities, such as deep sea mining, are banned in the monument. Meanwhile, recreational and traditional fishing deemed consistent with the conservation goals of the monument will still be allowed, the statement said.