Planting more trees, farming more sustainably and conserving wetlands could significantly slash the amount of carbon emissions that humanity spews into the atmosphere through fossil fuel use, researchers said Monday.

Better land use could reduce carbon dioxide 37 percent, enough to hold global warming below two degrees Celsius by 2030, as called for by the 2015 Paris Agreement, according to a report in the peer-reviewed Proceedings of the National Academy of Sciences.

Natural climate solutions could reduce emissions by 11.3 billion tons per year by 2030, which is equivalent to halting the burning of oil, it said.

"That is huge potential, so if we are serious about climate change, then we are going to have to get serious about investing in nature, as well as in clean energy and clean transport," said Mark Tercek, chief executive officer of The Nature Conservancy, one of the institutions which contributed researchers to the study.

At present, land use contributes about a quarter of the planet's carbon emissions, the leading greenhouse gas that causes the planet to warm up.

According to researchers, the biggest way to slow down climate change is by planting more trees and stopping deforestation, since trees absorb large amounts of carbon from the atmosphere.

Better stewardship of forests "could cost-effectively remove seven billion tons of carbon dioxide annually by 2030, equivalent to taking 1.5 billion gasoline-burning cars off the roads," said the report.

Next in line is changing farming practices, which could "cost-effectively deliver 22 percent of emissions reductions according to the study, equivalent to taking 522 million gasoline cars off the road."

Smarter farming solutions include improving the use of chemical fertilizers to allow better crop yields and reducing emissions of nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide.

"Other effective interventions include planting trees among croplands and improved management of livestock," it said.

Finally, experts urge the conservation of wetlands and a halt to the draining of peatlands, which hold about one quarter of the carbon stored by the world's soils.

Peatlands are disappearing fast, with some 1.9 million acres (780,000 hectares) lost globally each year, largely due to palm oil cultivation.

"Their protection could secure a store of 678 million tons of carbon emissions equivalent a year by 2030 -- comparable to removing 145 million cars from the streets," said the report.

These nature-based solutions must be accompanied by cuts in fossil fuel, said co-author William Schlesinger, professor emeritus of biogeochemistry at Duke University.

"The results are provocative: first, because of the magnitude of potential carbon sequestration from nature, and second, because we need natural climate solutions in tandem with rapid fossil fuel emissions cuts to beat climate change," he said.