With record-breaking heatwaves and devastating wildfires making headlines this summer, it’s clear rapid climate solutions are needed to fight the climate crisis.

One way this could be achieved is through urban tree planting, according to founder and CEO of green search engine Ecosia, Christian Kroll, who says this could absorb carbon, improve air quality and build climate resilience in cities. 

Air Quality News spoke to Sophie Dembinski, Head of Public Policy & UK Country Manager at Ecosia about why trees are so important to tackling the climate emergency and Ecosia’s own reforestation projects.  

How was Ecosia founded as a company?

Ecosia was founded in Berlin 12 years ago by Christian Kroll, after he spent 10 months in South America visiting areas that had been deforested to make way for commercial agriculture and soy plantations. Frustrated at the lack of action taken by government and businesses to combat deforestation and climate change more broadly, he decided to create a purpose-driven company to restore endangered ecosystems and biodiversity hotspots around the world.

He decided to build a green search engine to help spread awareness of the climate crisis, provide greener consumer choices and generate revenues that could meaningfully contribute to global reforestation efforts.  Today, Ecosia is the world’s largest reforestation movement and has funded the planting of over 155 million trees around the world, has an annual revenue of €30m, as well as over 20 million global users. 

How does urban tree planting help to fight the climate crisis? 

When temperatures soar to 40°C as they did in London recently, a lack of greenery and trees in a city becomes a public health issue. Not only do they absorb carbon dioxide and reduce flooding, but they are an essential part of the cooling green infrastructure – and can cool the surrounding neighbourhood area by between 8 and 12 degrees, providing shade and bringing moisture back into the air.

Their benefits aren’t felt just in parks or on streets. If you have a tree in your back garden or near your flat, they massively improve local biodiversity and can reduce indoor temperatures by up to 4 degrees in the summer and increase temperatures by up to 6 degrees in the winter – whilst helping to improve air quality in densely populated areas from excess emissions from heating and air conditioning. 

Access to green spaces and trees also help boost wellbeing too – spending 20 minutes in a park is proven to significantly improve mental wellbeing and can boost patient recovery times. That’s why Ecosia has supported a number of urban initiatives, including greening areas of East London and planting thousands of trees across the country outside of NHS Hospital Trust sites in the UK to help boost wellbeing for staff, as well as provide shade and reduce air pollution levels. 

Are governments utilizing this tool enough?

No, far from it. When it comes to infrastructure development and city planning, trees have been historically undervalued and mature trees have been routinely cut down to clear space for highways, car parks and skyscrapers. Take HS2, the controversial highspeed rail infrastructure project, which was projected to ‘destroy or irreparably damage’ five internationally protected wildlife sites, 693 local wildlife sites, 108 ancient woodlands and 33 legally protected sites of special scientific interest. Within UK cities, up to 60 urban trees are lost a day, whilst in the US it’s thought to be up to 36 million trees a year. 

Urban tree planting might be more expensive than rural reforestation projects, but with 56.2% of the world’s population living in cities – the health and climate risks are well worth the investment.

What kind of urban tree planting reforestation projects has Ecosia led?

Ecosia dedicates 100% of profits to climate action which has allowed us to work with tree planting experts in over 35 countries across 13,000 planting sites – including in some urban areas.

Our urban tree planting projects take into account the complex socioeconomic realities on the ground, centering community voices to close the urban tree equity gap. But it’s not only about planting trees.

In London, as well as planting around hospitals in nature-deprived areas in the city, we’ve supported the community-led ‘Greener Together’ project which has helped to transform neglected areas into green spaces to combat social isolation and bring greater wellbeing to city residents. In Paris, we’re developing urban farming in Seine-Saint-Denis to help people reconnect with their food, the seasons and the soil. 

In the US, we’re working with City Plants in LA to revitalise an old municipal nursery in order to plant trees in the historically redlined neighbourhoods that are vulnerable to the urban heat island effect. As well, in Chicago, we’re working with Openlands to support Tree Ambassador programs which aim to train community members to plant, monitor and tend to urban trees. 

Have wildfires affected Ecosia’s own tree planting projects?

All of our partners report fires to us in the local area when there is a risk to our trees. Fortunately, none of our projects have been affected by wildfires so far but it’s an issue which is very close to our hearts and we are taking a number of preventative measures to combat the spread of wildfires globally.

For example, we’ve increased our investments and refocused our reforestation efforts in high-risk areas, such as Australia, where we’ve planted over 33,000 trees through our partner ReForest Now to restore areas devastated by forest fires and make them more resilient. 

Through fire-fighting-related investments, we have protected 13.8 million trees in places such as Brazil, where we support the firefighting organisation ITPA. As well, we will launch a project in Bouches-du-Rhône, France this autumn, to plant several hundred fire-resistant native species trees (holm oak, olive trees and strawberry trees) in an area prone to fires, whilst also focusing on raising awareness and educating the local population about forest fires and their underlying causes.

We are also working on a remote sensing fire detection alert to be rolled out across all of our projects globally.

From a planting perspective, there are a number of steps that can be taken to reduce the risk of wildfires. For example, we ensure we only plant native trees and forests with a strong species mix, never monocultures and never invasive species, As well, in areas with high wildfire risk we plant fire-resistant species too. From a policy perspective, in the reforestation community, we advocate for a number of steps to be taken to ensure trees are planted in the right place at the right time to avoid fires spreading.

Photo by Fons Heijnsbroek and Maximilian Zahn