The European Space Agency successfully launched its Biomass Earth Explorer satellite aboard a Vega-C rocket from the Guiana Space Centre in Kourou, French Guiana, on Thursday, marking a milestone in the agency's effort to quantify how much carbon is locked inside forest biomass worldwide. The satellite, years in development and repeatedly rescheduled, carries a unique P-band synthetic aperture radar capable of penetrating dense forest canopies to measure trunk and branch mass — the primary reservoir of terrestrial carbon storage.

The mission addresses one of the most persistent gaps in climate science: the uncertainty surrounding how much carbon tropical and boreal forests actually contain, and how quickly that reservoir is shrinking due to deforestation and degradation. Current estimates carry error margins of up to 50 percent, a figure that severely limits the reliability of national carbon accounting under the Paris Agreement. ESA mission scientists said Biomass is expected to reduce that uncertainty to below 20 percent within its first two years of operation.

Once in its 666-kilometre sun-synchronous orbit, the spacecraft's 12-metre deployable radar antenna will begin systematic passes over the Amazon basin, the Congo rainforest, and the boreal forests of Siberia and Canada — regions that collectively store an estimated 450 gigatonnes of carbon. Data will be made freely available to researchers, national governments, and climate monitoring bodies including the UN's Global Climate Observing System and the Copernicus Climate Change Service.

The launch was closely watched by climate negotiators and environmental NGOs preparing for the COP31 climate summit later this year in Brisbane, where forest carbon credits and REDD+ accounting methodologies are expected to be among the most contested agenda items. Proponents argue that independent satellite verification from Biomass could break a decade-long deadlock over whether market-based forest protection schemes actually deliver real emissions reductions.

ESA Director General Josef Aschbacher said the mission represented 'the most scientifically ambitious radar Earth observation satellite Europe has ever flown,' noting that P-band radar at this scale had never before been attempted from orbit. The satellite is expected to operate for at least five years, with a first global forest carbon map projected to be published within 18 months of commissioning.