Trees are not scenery.

This page collects verifiable findings, globally and for Germany. Where numbers are uncertain, we say so. Where they’re clear, we say that too.

Forests worldwide

According to the Global Forest Resources Assessment 2025 by the Food and Agriculture Organization of the United Nations (FAO), the world’s forests cover about 4.14 billion hectares. That’s roughly 32 percent of Earth’s land area, or 0.50 hectares of forest per person on paper, though forests are distributed very unevenly. The largest share lies in the tropics (about 45 percent), followed by the boreal, temperate and subtropical zones.

Since 1990, the FAO estimates, around 489 million hectares of forest have been lost to deforestation. The rate has slowed, but it hasn’t stopped: between 2015 and 2025, deforestation ran at an estimated 10.9 million hectares a year, down from 17.6 million (1990–2000) and 13.6 million (2000–2015). The net loss rate (deforestation minus forest gains from planting and natural expansion) fell from 10.7 million hectares a year in the 1990s to 4.12 million hectares a year in 2015–2025.

Net figures can be reassuring without making the situation any less serious. A young stand doesn’t simply replace an old, species-rich forest. A hectare of plantation is not the same as a hectare of primary tropical forest. That’s why the FAO distinguishes between deforestation and net change in forest area, and for good reason.

Germany: area is not condition

Germany’s fourth National Forest Inventory (survey year 2022) records about 11.54 million hectares of forest, roughly 32 percent of the country’s land. Compared with the 2012 inventory, the area grew slightly, by 15,000 hectares. Almost half of the forest is privately owned.

Area alone says little about health. The 2024 Forest Condition Survey by the responsible federal ministry (BMLEH) shows that 36 percent of the tree-species area has significant crown thinning, 43 percent is at the warning level, and only 21 percent shows no visible thinning. Taken together, about 79 percent of trees show signs of damage. Trees over 60 years old are hit hardest (43 percent with significant thinning, versus 16 percent of younger trees). For oak, the share with significant crown thinning was 51 percent in 2024.

Heat and drought since 2018, bark beetles and other pests, storms and an often too narrow mix of species have hit German forests hard. That the forest area has grown slightly is good news. It mustn’t hide the fact that many stands are under stress.

Trees and climate

Forests are both a sink and, where they are destroyed or degraded, a source of greenhouse gases. The Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6, Working Group III, Chapter 7) finds that agriculture, forestry and other land use (AFOLU) accounted for an estimated 13 to 21 percent of global human-caused greenhouse gas emissions in 2010–2019. At the same time, managed and natural terrestrial ecosystems took up around a third of anthropogenic CO₂ emissions (medium confidence).

According to the IPCC, protecting, better managing and restoring forests and other ecosystems are among the most important mitigation options available in the near term. The potential is especially large where tropical deforestation declines. Land-based measures cannot, however, make up for delayed emission cuts in other sectors.

Then there’s everything that can’t be captured in a single carbon figure: biodiversity, local climate, the water cycle, erosion control, recreation. A felled old tree releases stored carbon and takes a habitat with it that new planting will only approximately replace after decades, sometimes centuries.