Human activities like increased deforestation and the burning of fossil fuels are making it harder for natural processes on Earth to maintain the planet's carbon cycle balance, NASA scientists say in announcing a new satellite to measure the phenomenon.

The space agency's Orbiting Carbon Observatory-2 (OCO-2) set to launch in July will examine and analyze the movement of carbon around the globe as natural processes work to absorb greenhouse gas emissions, keeping the carbon cycle balanced to limit the impact of climate change.

"Right now, the land and the ocean are taking up almost half of the carbon dioxide we add to the atmosphere by burning fossil fuels, but the future is fundamentally unknown," Paul Wennberg, an atmospheric chemist at the California Institute of Technology, says. "OCO-2 is a key to getting answers."

NASA scientists at the agency's Jet Propulsion Laboratory in Pasadena, Calif., have developed the OCO-2 mission.

While average atmospheric concentrations of CO2 can be accurately monitored by about 160 ground stations around the globe, the roughly half being absorbed in natural processes on the oceans or on land is unevenly distributed and more difficult to measure, the researchers said.

OCO-2 will help by providing comprehensive, precise and ongoing data of CO2 emission and absorption in oceans, forests and other regions, they said.

Research ships that cross the world's oceans move slowly to effectively gather large amounts of data, Scott Doney of the Woods Hole Oceanographic Institution in Massachusetts says.

"A research ship moves about the speed of a 10-speed bicycle," Doney says. "Think about the size of the ocean. There's only so much research you can do at the speed of a bicycle."

And the vast expanse of Earth's forests also makes gathering data difficult.

In the north of Siberia, for example, where there are few roads or permanent settlements, just six monitoring stations spread over seven separate time zones struggle to keep up with measurements of forests acting as global carbon sinks.

OCO-2, with its worldwide observations, will help answer questions about the working of the carbon cycle in such little-monitored regions, JPL manager of the OCO-2 project Ralph Basilio says.

"With atmospheric carbon dioxide at unprecedented levels, our sense of urgency has only increased," he says. "What will happen if we keep emitting carbon dioxide at the same rate? The ultimate goal for OCO-2 is to provide data so that organizations and individuals throughout the world can make better-informed decisions about carbon."