Impacts on communities and livelihoods: The project threatens to disrupt traditional and ecological farming practices, which many local families have relied on for generations. By altering the landscape and potentially polluting nearby soil and water sources, it risks impacting the quality of yields and forcing farmers off their land.

Pesticides sprayed on eucalyptus plantations and chemicals derived from the pulp process such as phosphorus, sulphates, and nitrogen, together  with heat contamination of water from the pulp mill, could severely affect fish populations and aquatic ecosystems, jeopardising both small-scale fishing operations and established aquaculture businesses in the Arousa estuary – a high-value ecosystem with a very important community dedicated to artisanal fishing and extensive shellfish production.

With over 800 private plots of land affected, the project will impact many rural jobs in the region, and risks displacing residents and destroying community life.

Health impacts of emissions: According to the Environmental Impact Assessment (EIA) submitted by Greenfiber S.L., the joint venture between Altri and Greenalia, the projected annual emissions are:

• 252.5  tonnes/year of PM10, which is associated with increased risk or worsening of existing respiratory problems such as asthma and Chronic Pulmonary Obstruction Disease (COPD), increased risk of cardiovascular diseases such as heart stroke and heart diseases and increased risk of lung cancer;
• 577.6 tonnes/year of SOx, which is associated with increased risk or worsening of existing respiratory problems such as asthma, increased risk of chronic respiratory illness with long exposure, increased blood pressure;
• 2,771 tonnes/year of NOx, which is associated with increased risk of respiratory problems such as irritation, aggravated asthma, respiratory infections, chronic lung disease and others, increased risk of cardiovascular problems such as heart risk, hypertension, stroke, myocardial infarcts, increased risk of neurodegenerative diseases such as Parkinson’s and Alzheimer’s.

Increased risk of wildfires: Climate change is making wildfire seasons longer and more intense. The GAMA project will use 1.2 million cubic metres of eucalyptus during Phase I. Eucalyptus plantations are known for being highly flammable, as they are highly water-thirsty trees, consuming up to 60 litres of water a day, draining the soil and increasing the risk of large wildfires. To supply eucalyptus demand for the planned pulp plant, Galicia will probably have to increase the area of its eucalyptus monocultures by 190,000 hectares in a region already oversaturated with eucalyptuses and that already struggles every year with forest fires.

The growing number of large wildfires due to the propagation of eucalyptus monocultures further contributes to climate change by emitting more CO2. Studies estimate that, between 1997 and 2016, wildfires worldwide are responsible for emitting 8 billion tonnes of CO2 per year.

Over the past years, eucalyptus plantations in Europe, particularly in Portugal and Spain, have been significantly affected by wildfires. For example, the 2017 Pedrógão Grande wildfires in Portugal resulted in 66 fatalities and burned nearly 50,000 hectares. Satellite mapping indicated that eucalyptus and pine plantations comprised approximately 70% of the burned area. In September 2023, wildfire consumed over 21,000 hectares around Albergaria-a-Velha, also in Portugal, an area with extensive eucalyptus plantations. The Navigator Company, a major eucalyptus pulp producer, confirmed its plantations were affected by the September fires, but said the eucalyptus tree itself was not the main cause, pointing instead to strong winds, high temperatures and low humidity at the time. In 2022, the Boiro wildfires near A Coruña in Northern Galicia, Spain, burned approximately 2,200 hectares.

Impacts on carbon emissions: The eucalyptus monoculture plantation model captures less carbon dioxide than native species, as trees are cut after just a few years, impacting these plantations' ability to store carbon.

The company misleadingly presents the burning of woody biomass as green energy. Energy from woody biomass is increasingly recognized as a high-carbon source of energy; it emits more CO2 than coal per unit of energy, and the increased logging rate would further exacerbate wood consumption and generate emissions, undermining Spain’s climate targets.

Overconsumption of pulp: The project’s demand for eucalyptus is estimated at 1.2 million cubic metres during the project’s first phase. Galicia already produces 70-90% of Spain’s eucalyptus volume, with over 420,000 hectares of eucalyptus plantations.

Although this part of the Serra do Careón area was included in the proposed expansions of the Natura 2000 Network drafted by the Xunta de Galicia in 2008 and 2012, these proposals were never implemented, despite the fact that Galicia has the smallest share of protected Natura 2000 territory in Spain (just 12% of Galician territory). While the Altri project cannot be directly linked to the decision not to proceed with those earlier expansion plans—given that it came much later— the area's exclusion from Galicia's 2025 Green Infrastructure Strategy does coincide with the project's development. This exclusion, while distinct from the earlier Natura 2000 proposals, still has important implications for nature protection and restoration efforts under the EU’s Nature Restoration Law.

Water usage and discharge: Altri is requesting a permit that will allow it to consume 46 million litres of freshwater from the Ulla River per day, equivalent to 18 Olympic-sized swimming pools or the daily water use of over 300,000 people. The company is applying for a 75-year permit, without any assessment of the future effects of climate change on the water supply in the region.

The pulp mill will discharge 30 million litres of treated wastewater per day. The water will be discharged to the Ulla River, part of the Natura 2000 network, above the catchment area, with the consequent impact on the entire basin and probably on the Arousa estuary, damaging biodiversity, altering the salinity and nutrients in the water, with a serious impact on coastal ecosystems and its productive sectors.

Impact on habitats: The expansion of eucalyptus monocultures will negatively affect local and regional wildlife and biodiversity, as this report from the Galician Council of Culture highlights. The eucalyptus is a highly flammable, highly water-thirsty tree that drains the soil, increases the risk of large wildfires and prevents any wildlife from flourishing, directly countering the much-needed efforts to increase biodiversity.

The land used to build the pulp mill contains habitats of community interest, directly impacting endangered endemic species (three of them strictly endemic: Santolina melidensis, Armeria merinoi and Leucanthemum gallaecicum).

Within the scope of the project, more than 140 bird species have been recorded, of which four are included in the Galician Catalogue of Endangered Species and six in the Spanish Catalogue of Threatened Species, as organizations such as Birdlife/SEO have denounced. The Galician government recognises at least 27 endangered species that will be impacted directly by the project, three of them being unique in the world.

In addition, other endangered species would be affected in the Ulla River. A report from the Galician Council of Culture reflects these concerns. Another report of the Galician Society of Natural History, which seats in the Galician Council for the Environment and Sustainable Development of the Xunta de Galicia, points to the several river species such as the Margaritifera mussel that will be affected by the effluent discharges in the river.

Experts consider this region “one of the most important zones of the Iberian Peninsula" for plant biodiversity, making it particularly unsuitable for a project of such scale and impact such as this.

There is common agreement among the scientific community that a healthy environment and well-functioning biodiversity may represent a decisive factor in preventing pandemics, while eroded habitats and disturbed dynamics of biodiversity is where the transmission of diseases to humans from animals may likely happen. Avoiding the expansion of monocultures in Galicia is therefore a priority.