Almost half of the Earth’s land surface must be protected to stop the biodiversity crisis, according to a new report published Friday in the journal Science. 

The research found some 64 million square kilometers (24.7 million square miles) – 44% of the Earth’s land – needs “conservation attention” to prevent major biodiversity losses.

“We must act fast, our models show that over 1.3 million square kilometers of this important land – an area larger than South Africa – is likely to have its habitat cleared for human uses by 2030, which would be devastating for wildlife,” lead author Dr James R. Allan from the University of Amsterdam said in a news release.

The study, which used advanced data modeling and algorithmic projections to map optimal areas for conserving species and ecosystems was described by the authors as “a conservation plan for the planet.”

The authors said those areas didn’t necessarily have to be designated as protected areas, but other strategies could be used to conserve ecosystems including policies to control land use.

The new research also found that 1.87 billion people, roughly a quarter of the Earth’s population, live in areas requiring conservation attention, mostly in developing countries in Africa, Central America and Asia.

Climate scientists and environmental groups are urging governments and corporations to do more to protect the planet, amid warnings the world is on track to miss its targets of keeping warming below 1.5 degrees Celsius.

Scientists who wrote the new research say their findings could have important implications for policymakers negotiating global biodiversity targets, after governments failed to meet the previous goals to conserve at least 17% of global land area by 2020.

A coalition of 70 countries are expected to pledge to to protect 30% of their lands and oceans by 2030, in a draft global treaty due to be finalized in the third quarter of this year.