ESA budget cuts a major blow to CarbonSat - Earth climate science

CarbonSat Image Credit: Astrium

ESA’s funding shortfall is bad news for CarbonSat, a mission aiming to track atmospheric carbon dioxide.

For Europe’s space chiefs, the outcome of last week’s European Space Agency (ESA) budget negotiations was better than expected, given the continent’s economic troubles.

But for Volker Liebig, ESA’s head of Earth Observation programmes (EOP), there is a sting in the agreement.

The multi-year budget that member states approved — which falls some €2 billion (US$2.6 billion) short of ESA’s proposed spending of about €12 billion — could force him to postpone or cancel a mission aimed at pinning down the mysterious carbon sinks that are slowing the rise of greenhouse gases in Earth’s atmosphere.

Ahead of the budget negotiations in Naples, Italy, on 20–21 November, Liebig had hoped to secure around €1.25 billion for new research satellites.

With France, Italy and Spain contributing much less than expected, he received €1.9 billion for Earth-observation projects.

But €808 million has already been allocated for a new generation of weather-forecasting satellites, leaving him with little more than €1 billion for research missions.

“We have to discuss with scientists in the next few weeks what to do,” Liebig says. “But we will not be able to develop all the science satellites we wanted to.”

Most vulnerable, he says, is a planned €250-million climate-change mission scheduled for launch in about 2018.

One of the two contenders for the mission, CarbonSat, would map atmospheric concentrations of carbon dioxide and methane at high-enough resolution to investigate a long-standing puzzle: why only about half of the CO₂ emitted by human activities remains in the atmosphere.

Scientists assume that the rest is absorbed largely by the oceans and plants, but ground-based monitoring stations are too few and far apart to pinpoint the sinks.

Satellites could fill in the gaps in the picture, but in April ESA lost contact with Envisat, the one satellite providing such data (see Nature 484, 423–424; 2012).

Neither Japan’s existing Greenhouse Gases Observing Satellite nor NASA’s Orbiting Carbon Observatory-2 (OCO-2), scheduled for launch in 2014, will map greenhouse-gas concentrations in as much detail as CarbonSat, which would survey the whole globe with a resolution of 4 square kilometres.

“The information that it would collect is essential for developing, implementing, and monitoring greenhouse-gas-emission policies,” says atmospheric physicist David Crisp of NASA’s Jet Propulsion Laboratory in Pasadena, California, who is the science team leader of OCO-2. “A timely launch of this satellite should be among the highest priorities of ESA”.

CarbonSat’s competitor for ESA funding, FLEX, would also help to pin down carbon sinks, by measuring the faint fluorescence generated by plants during photosynthesis — a measure of how efficiently they absorb carbon.

“The last thing we want to do is to destroy the forests or whatever is absorbing almost half of the CO₂ that we are emitting,” says Crisp.

“Wouldn’t it be good to know where these processes are occurring?”