Author: worldrfnews

Mangroves, the amphibious forests that fringe tropical and subtropical coastlines, are ecological powerhouses. They buffer communities against storm surges, support fisheries, and sequester carbon at rates that rival their terrestrial counterparts. Yet despite growing recognition of their value, mangroves remain imperiled. About 35% of global cover was lost in the late 20th century, largely to aquaculture and coastal development.

New research offers the most comprehensive look yet at the cost of reversing that damage. Drawing on nearly 250 projects and dozens of data sources, researchers have created the first global model of site-specific mangrove restoration costs. They find a median implementation cost of $8,143 per hectare, with wide variability: From just $9 to over $700,000. Site conditions matter. Rehabilitating abandoned shrimp ponds tends to be cheap; replanting eroded or hydrologically disrupted coastlines is far pricier.

Indonesia, with its vast archipelago and degraded deltas, holds the greatest potential. At least 204,000 hectares could be restored at less than $10,000 per hectare—making it a focal point for meeting national and international targets. Globally, 1.1 million hectares of mangroves could be restored for $10.73 billion, or roughly what Americans spend on pet food every three months. That could remove up to 0.93 gigatons of CO₂ from the atmosphere, at an average cost of $11.49 per ton.

Such figures are competitive in the world of carbon markets, where blue carbon credits—those derived from coastal ecosystems—are gaining traction. But for now, the market is nascent.

Carbon finance alone is unlikely to underwrite the global mangrove revival. Opportunity costs—such as forgone aquaculture profits—could more than double restoration expenses. And the true success of such efforts will depend not just on trees planted or credits sold, but on long-term governance, local engagement, and ecological resilience.

Still, this cost model offers a tool for prioritizing investment. Where resources are scarce and climate ambitions high, identifying the most cost-effective hectares could help steer restoration efforts toward both fiscal prudence and environmental payoff.

CITATION: Garrett M. Goto et al. Implementation costs of restoring global mangrove forests. One Earth
Volume 8, Issue 7, 18 July 2025, 101342. https://doi.org/10.1016/j.oneear.2025.101342

Despite mounting global pledges to stem deforestation, a new study published in Nature Communications finds that 17% of tropical tree cover—nearly 396 million hectares—has gone overlooked by mainstream forest monitoring systems.

Using high-resolution satellite imagery and machine learning, an international team of researchers has mapped this previously undetected tree cover (PUTC), revealing that significant changes are taking place well beyond the traditional forest frontier.

Between 2015 and 2022, net tropical tree cover shrank by more than 61 million hectares. While most of that loss occurred in forests, over a third happened in areas not typically classified as forest: Croplands, grasslands, and urban spaces. These are precisely the areas where existing tools such as the World Cover dataset, with its 10-meter resolution, tend to fail.

“Neglecting scattered trees has led to a systematic underestimation of ecological degradation,” said Liu Shidong, the study’s lead author, via a Chinese Academy of Sciences press release.

The study found that 54% of tree cover loss was linked to land-use change and deforestation, while 44% of gains were driven by increased rainfall. Human activity—including logging and expansion of agriculture—emerged as the dominant driver of decline. The most substantial gross losses occurred in Brazil, Indonesia, and the Democratic Republic of Congo.

Beyond simply identifying losses, the research highlights a mismatch between deforestation data and restoration goals. In 2021, 141 nations pledged to halt forest loss by 2030 under the Glasgow Declaration. Yet the study recorded a gross gain in tree cover of just 6.2 million hectares across the tropics, barely a tenth of what was lost. Brazil, for instance, gained only 1.36 million hectares over the eight-year period, far short of its Bonn Challenge target of restoring 4.28 million.

Much of the newly detected cover sits in places long classified as treeless. In Africa, for example, more than a quarter of shrubland and grassland tree cover had been missed. In Asia, significant PUTC was found in croplands and cities. These trees matter: they sequester carbon, cool microclimates, and sustain livelihoods.

The methodology, which achieved 97.3% accuracy, could offer a more consistent and scalable way to track global tree dynamics, argue the authors.

“Fine-scale mapping is essential for credible climate mitigation,” said Wang Li, the project’s principal investigator, in the release.

The findings call into question long-standing assumptions about where trees grow—and where they are disappearing. In the battle against climate change, it seems, the world has been flying partially blind.

🔬 Shidong Liu et al, Mapping previously undetected trees reveals overlooked changes in pan-tropical tree cover, Nature Communications (2025). https://www.nature.com/articles/s41467-025-60662-z

In a corner of the rainforest where Colombia meets Peru and Brazil, the hum of chainsaws and gunfire never quite dies. Yet in the shadows of this long emergency, a sublter resistance endures. Its front line is not marked by barricades or armed patrols, but by walking sticks carved from peach palm and a deep, unshakable intimacy with the land, reports Daniela Quintero Díaz.

Luis Alfredo Acosta has walked this path for 35 years. A member of the Nasa people and national coordinator of the Indigenous guard under the National Indigenous Organization of Colombia (ONIC), he speaks with clarity shaped by decades of witnessing promises deferred and communities displaced.

“Although these appear to be isolated things… it really is an integral resistance,” he said. “Because at its core, all of this only works if there is land.”

In Colombia’s Amazon region, “resistance” is neither metaphor nor battle cry. It is physical: Guarding against armed groups, illegal loggers, and narcotraffickers. It is intellectual: Preserving ancestral knowledge and mapping sacred sites. It is spiritual: Sustained through rituals and the use of yagé. And it is cultural: Enacted in daily life through small farms, seed banks, and forest patrols.

That these efforts persist amid violence is remarkable. Of the 1,411 human rights defenders killed in Colombia over the past decade, at least 70 were Indigenous guards. In many areas, the state has withdrawn: 11 protected zones in the Amazon are now inaccessible to park rangers due to armed conflict. Yet forests within Indigenous territories remain largely intact, with 98% cover — a fact both defiant and tragic.

The guards, often unpaid, rely on collective will more than resources. In Putumayo, the Siona community has removed mines and monitored vast forest tracts. In Guainía, fishers have transformed kitchens into labs, contributing to national fishery policies. In Amazonas, communities reforest thousands of hectares using knowledge handed down through generations.

The state’s support has been halting. President Petro’s National Development Plan pledged to strengthen Indigenous guardianship, but funding has been piecemeal. For guards like Olegario Sánchez of the Tikuna, even basics like radios or canoes are scarce.

“If we leave the territory,” a Siona guard warned, “we get closer to dying. If a root dies, its essence dies. And the principle of a community dies.”

In the Amazon, the forest still stands. But its fate — and that of its guardians — hangs in the balance.