The ban is the centrepiece of an important climate deal with Norway, signed last year, worth up to $1 billion. A major goal is to cut greenhouse gas emissions from deforestation, by far the largest source of emissions in Indonesia.

Improving land tenure and land planning rules are other goals of the scheme that began in May, which has met strong resistance from some miners and planters. They fear it could crimp growth by curbing access to land.

An analysis of the moratorium by the Centre for International Forestry Research (CIFOR) in Indonesia shows large areas of forest rich in species and stores of carbon are still at risk of clearance, limiting the chances of a major cut in emissions.

Indonesia has the world’s third-largest area of tropical forests, which play a major role in braking the pace of climate change because they soak up large amounts of planet-warming carbon dioxide.

Ever greater demand for land and resources such as coal, and food such as palm oil, is threatening remaining forest cover, with about 1 million hectares (2.5 million acres) lost annually.

CIFOR, in the study released on Friday, said while the moratorium on licences was a good start: “Several issues are unresolved concerning the area and status of land covered by the moratorium, and hence the amount of carbon stored in the affected forests and peatlands”.

It found that the total new area protected under the moratorium was, at most, 22.5 million hectares, of which a third were primary forests and half were peatlands.

That is less than half some previous government estimates because large areas of primary forests and peatlands are already legally protected, although still at risk of encroachment.

The study described the failure to include secondary forests and logged-over forests in the moratorium as a lost opportunity to protect, at least temporarily, a fraction of 46.7 million ha of forests rich in carbon and biodiversity.

It said millions of hectares of peatland and primary forests were still not covered by the moratorium either because of existing concessions or planned investments deemed vital to national development.

Giant carbon store

Indonesia has about 20 million ha of peatlands estimated to contain 30 billion tonnes of carbon — roughly the equivalent of mankind’s total greenhouse gas emissions over three years. That explains why Indonesia and Norway are keen to preserve what is left of these vast carbon stores to fight climate change.

Also at risk of undermining the ban were a range of exemptions, such as rice, sugarcane and geothermal investments deemed in the national interest, and the exclusion of existing licences to use forest land so long as the licence remained valid regardless of the licence-holder’s performance.

“The moratorium’s exceptions for activities related to food and energy security create loopholes that could undermine the suspension of new concession licences,” the study says, calling for a greater focus on land swaps involving degraded land before any exceptions are granted.

Norway says it is broadly happy with the climate deal and will measure success based on analysis of six-monthly satellite maps of forest cover.

“Our demand was, and still is, that in the reasonably near future we have to see improvements in what actually happens to the forests,” said Per Fredrik Ilsaas Pharo, deputy director of Norway’s International Climate and Forest Initiative.

He also pointed to the threat from corruption and powerful business interests.

“We all know there is also corruption and other illegal activities going on but there is actually a legitimate internal Indonesian discussion about what pathway to take forward. And clearly it’s not a given that they will choose the model that we would like them to choose,” he told Reuters from Oslo in a recent interview.