Human Pressures in 2025

Increasing pressures from rising greenhouse gas emissions and overexploitation are degrading Ocean health. Pollution and habitat loss-especially in coastal areas-are intensifying these challenges, while gaps in global monitoring systems continue to hamper effective responses.
Ocean StateSocietal Harms
Ocean StateSocietal Harms

Fossil fuel CO2 emissions are rising, including a 2.7% increase from shipping.

The 2024 Global Carbon Budget projects global fossil carbon dioxide (CO2) emissions of 37.4 billion tonnes, up 0.8% from 2023. Emissions from international shipping are also on the rise, with a projected 0.6 billion tonnes of CO2 in 2024 (representing 1.6% of total global emissions), up 2.7% from 2023; these figures rely on countries’ self-reported data regarding fuel sales for international shipping. Fossil fuel CO2 emissions are the main contributor to recent climate change. They also lead to ocean acidification as approximately one-third of these emissions are absorbed by the Ocean.

Unsustainable fishing hits 37.7%, while 75% of large vessels go untracked.

The percentage of marine stocks fished at unsustainable levels (i.e. beyond maximum sustainable yield) has increased since the mid-1970s, from 10% in 1974 to 37.7% in 2021. Marine fisheries activities involve approximately 4.9 million registered motorized and non-motorized fishing vessels in 2022. This estimate represents only part of the unsustainability challenge, as it does not account for broader ecological and social impacts of fisheries, nor for IUU fishing. An estimated 75% of large (>15m) fishing vessels operate without proper tracking, challenging growing efforts to combat IUU fishing and to regulate marine protected areas (MPAs).

Rising human and climate pressures threaten marine habitats globally.

A combination of growing pressures is involved, including unsustainable fishing practices, pollution, ocean warming, acidification, and oxygen loss pushing marine ecosystems and species beyond their tolerance limits. Climate change is driving the loss of suitable habitats globally, with the most pronounced shifts in species richness occurring in tropical ecosystems. Coastal ecosystems are also showing increasing signs of degradation. Since 1950, coastal hypoxia has increased tenfold, reducing the extent and quality of coastal habitats critical to marine biodiversity. Climate change and pollution-driven eutrophication have caused a rise in the reporting of nearshore macroalgal blooms (green tides) worldwide over the past two decades, although comprehensive global estimates are lacking. 50% of mangrove ecosystems are at risk of collapse, over half of World Heritage seagrass habitats have high vulnerability to climate change, while 33% of the world’s sandy coastline is currently hardened by man-made structures. The multiple uses of coastal areas — like coastal infrastructures, tourism, fish farming, and offshore structures — are putting more pressure on ocean habitats, through pollution, habitat destruction, increased risks of marine pathogens, parasites and invasive species, especially as coastal populations grow: in 2018, about 2.2 billion people, or 30% of the world’s population, lived within 50 km of the coast.

Plastic pollution is rising but still no global system to monitor and assess it.

Global plastic production has surged from 2 million tonnes (Mt) in 1950 to 413.8 Mt in 2023, of which only 8.7% is from recycled origin. Plastic waste accounts for over 80% of identified aquatic debris. In 2021, plastic accumulation in rivers and the Ocean was estimated at 75–199 Mt. Marine plastic pollution has been reported since the 1970s, but the absence of a unified global monitoring system still hampers effective assessment and response.