Milan Plants 3 Million Trees to Fight Europe's Worst Air

One of Europe's most polluted cities is transforming into an urban forest. Milan is planting three million trees and shrubs over the next four years to clean its smog-filled streets and bring nature back to one of Italy's most densely populated areas.

The transformation is already underway. Since 2019, the Forestami project has planted nearly 640,000 trees and shrubs across the city, restoring about 350 football fields worth of degraded urban spaces including former industrial sites, parking lots and storage yards.

The Italian metropolis desperately needs the greenery. An October 2026 air quality ranking placed Milan seventh among the world's most polluted cities and the only European city on the list.

Italian architect Stefano Boeri, creator of Milan's famous vertical forest building, launched Forestami with a clear goal: plant roughly one tree for every city resident. The organization says adding greenery to streets, rooftops and building facades is the cheapest and most effective way to filter fine dust, cool the city and improve people's wellbeing.

The effort is paying off. On October 29, the United Nations named Forestami a World Restoration Flagship at the UN Biodiversity Conference in Armenia, joining just four other projects worldwide to receive the honor.

The Ripple Effect

Milan's green makeover shows what's possible when cities commit to restoration at scale. The project engages schoolchildren in plantings and expands access to green space for residents across the metropolitan area.

The recognition comes as the UN reports the largest documented restoration effort in history. Across 149 countries, 252 million hectares are being restored, a movement that could generate 32 million new jobs worldwide by 2030.

Restoring just 15 percent of global priority areas could capture 30 percent of carbon dioxide emissions since the industrial revolution and help prevent 60 percent of species extinctions. For Milan residents, the benefits are more immediate: cleaner air, cooler temperatures and more beautiful neighborhoods.

Progress needs to accelerate. At the halfway point of the UN Decade on Ecosystem Restoration, nature isn't recovering fast enough to meet global targets, and restoration funding must more than quadruple.

But Milan proves that even Europe's most polluted cities can change course. What started as an ambitious plan to green one Italian metropolis has become a blueprint for urban restoration worldwide.