World leaders must increase their commitments to conserving land and water, and quickly, if a stable climate and high quality of life are to be preserved in the near future, a new scientific study argues. Countries should double their protected zones to 30 percent of the Earth's land area, and add 20 percent more as climate stabilization areas, for a total of 50 percent of all land kept in a natural state, scientists conclude. All of this needs to be done by 2030 to have any real hope of keeping climate change under the "danger zone" target of 2.7 degrees Fahrenheit and to prevent the world's ecosystems from unraveling-according to an ambitious plan called the Global Deal for Nature.

"The benefits of protecting 50 percent of nature by 2030 are tremendous," says Eric Dinerstein, director of biodiversity and wildlife solutions at RESOLVE, a non-profit group, and lead author of a new paper published Friday in Science Advances titled "A Global Deal For Nature: Guiding principles, milestones, and targets."

This is the first science-based plan with clear milestones on why it's vital to achieve these goals and how it could be done, says Dinerstein. It's not widely understood that large areas of forests, grasslands, and other natural areas are needed to soak up carbon emissions, he adds. Intact forests and especially tropical forests sequester twice as much carbon as planted monocultures, for example.

Only when 50 percent of the Earth's terrestrial areas are protected, along with substantial cuts in fossil-fuel use and major increases in renewable energy, will we have a good chance of meeting the Paris climate target of fewer than 2.7 degrees Fahrenheit of warming, the scientists argue. And if warming goes beyond 2.7 degrees Fahrenheit, we lose some of those natural systems and the services they provide humanity, including their ability to absorb carbon, Dinerstein says. "We can't have a safer climate without protecting 50 percent of the Earth and vice versa."

"Every morsel of food, every sip of water, the air we breathe is the result of work done by other species. Nature gives us everything we need to survive," says Enric Sala, a National Geographic Explorer-in-Residence and lead of the National Geographic Society's work as part of the Campaign for Nature, a partnership with the Wyss Campaign for Nature to inspire the protection of 30 percent of the planet by 2030.

"Without them, there is no us," said Sala, noting that we are losing "them" at an accelerating rate and are close to a tipping point.

"If we had to manufacture our own oxygen it would cost 1,600 times the entire global GDP-if it was even possible," said Sala, who is a co-author of the Global Deal for Nature study.

Countries have already committed to protecting 17 percent on land and 10 percent of the oceans by 2020 under the Convention on Biological Diversity, or CBD. Yet most countries are not on target to meet the 2020 goals. The US is not a signatory to the convention. The head of the CBD, Cristiana Pașca Palmer, has said half of the world must be protected and nations will consider this proposal at a major meeting in China in 2020.