A major United Nations environmental assessment has warned that the world must urgently adopt a unified strategy to tackle climate change, pollution, biodiversity loss and land degradation, describing them as deeply interconnected crises that threaten global stability and human survival.

The report, produced by the UN Environment Assembly with input from nearly 300 scientists across more than 80 countries, is considered the most comprehensive global environmental assessment to date. It concludes that fragmented, issue-by-issue approaches have failed to deliver meaningful progress and that only coordinated action across governments, industries, financial institutions and civil society can prevent irreversible environmental damage.

According to the assessment, environmental pressures are placing more than one million plant and animal species at risk of extinction, while also undermining food security, water availability, human health and economic stability. Climate change, land degradation and pollution are described as mutually reinforcing threats that accelerate ecosystem collapse and increase the vulnerability of communities worldwide.

The report highlights that global greenhouse gas emissions reached record levels in 2024, largely driven by continued dependence on coal, oil and natural gas. Despite almost 200 countries committing under the international Paris climate framework to limit global temperature rise to 1.5 degrees Celsius above pre-industrial levels, current trends suggest warming could reach approximately 2.4 degrees Celsius by the end of the century. Such a trajectory is expected to intensify extreme weather events, including heatwaves, storms, droughts and wildfires, while further damaging forests, soils and freshwater systems.

Land degradation has already affected up to 40 per cent of the Earth’s land surface, reducing agricultural productivity and increasing the risk of desertification. At the same time, air, water and soil pollution are linked to an estimated nine million premature deaths every year, placing a significant burden on healthcare systems and national economies. The report notes that climate change acts as a threat multiplier, worsening biodiversity loss, deforestation and ecosystem instability.

The assessment calls for a fundamental shift towards a circular economy that minimizes waste, maximizes resource efficiency and reduces reliance on fossil fuels. It recommends increased public and private investment in renewable energy, sustainable agriculture, waste reduction and ecosystem restoration. Financial incentives and policy reforms are identified as critical tools to accelerate these transitions.

While acknowledging that the required transformation will be costly, the report emphasizes that inaction will be far more expensive. It estimates that achieving net-zero emissions by 2050 and restoring biodiversity will require global investments of approximately $8 trillion annually. However, it projects that by 2050, economic returns from avoided climate damage and improved ecosystem services will begin to exceed costs, delivering benefits worth trillions of dollars each year and rising sharply in the decades that follow.

The report also urges countries to move beyond traditional economic indicators such as gross domestic product, arguing that current metrics fail to capture environmental degradation or the long-term sustainability of economic growth. Instead, it advocates for new measures that reflect ecosystem health, social well-being and resource security.

Despite the urgency outlined, the report raises concerns about weakening international cooperation. It notes that recent global negotiations on climate and plastic pollution have stalled, and that participation by major economies in key environmental forums has become increasingly inconsistent. The lack of strong, collective political commitment is identified as a major barrier to effective global action.

Even so, the assessment concludes that transformative change remains possible if nations act decisively and in coordination. It warns that the window to avoid the most catastrophic outcomes is rapidly closing and that delays will lock in damages that are far more difficult and costly to reverse. The report frames the environmental crisis not as a distant threat, but as an immediate challenge that will determine the future stability, health and prosperity of human societies worldwide.