(CNN) Where conservation meets bottom line, too often there's only one winner. At this critical juncture in the fight against climate change, scientists have warned we are on track to miss long-term international emissions carbon targets thanks partly to a rise in deforestation around the world.

"I think we as humanity need to realize that at some point enough is enough. We can't eat money in the end," says Christian Kroll.

Kroll, the founder and CEO of internet search engine Ecosia, doesn't mince his words. A radical when it comes to business and environmentalism, he bemoans big tech ("they create problems that they then try to solve with technology") and believes "the Western view on agriculture ... is slowly ruining our world." Yet, somehow, he remains a beacon of positivity.

Ten years ago, Kroll founded Ecosia as an alternative to the search engine giants. Its mission statement was simple: use its profits to plant trees -- millions of them.

You may not have heard of the search engine, let alone used it, but it offers a lesson in scale. Like Google, it creates revenue from advert clicks on its search pages, with around half of it spent on planting. Ecosia, which uses Microsoft's Bing for its backend, says one search generates on average €0.005 (just over half a US cent) -- not much, however approximately 45 searches pay for the planting of one tree. So far it has financed 75 million trees planted worldwide across 22 projects and 17 countries, from Brazil to Burkina Faso.

A decade in, Ecosia maintains its long-term goal to plant 1 billion trees and is beginning to diversify its offerings. It also has grander plans to reform what it means to be a business in the 21st century. So can we click our way out of a crisis?

Turning deserts green

Saplings waiting to be planted by an Ecosia-financed project in Senegal.

The reason Ecosia wants to plant trees is obvious: they're good for the planet and good for us.

According to a bombshell UN climate report from 2018, it's not enough that we curb carbon emissions in the years ahead; atmospheric carbon dioxide levels need to reduce to keep global warming below 1.5 degrees Celsius.

Trees absorb carbon dioxide and large-scale tree planting has been identified as one way to mitigate climate change. One recent report estimated that restoring the world's lost forests by planting one trillion trees could remove from the atmosphere two thirds of all carbon emitted by human activity since the industrial revolution ( some 205 billion tons ) -- although some have questioned that figure.

Ecosia claims one search on its platform will remove one kilogram of CO2 from the atmosphere . The company has built solar farms to meet its energy needs and offset its share of the carbon footprint generated by its use of Microsoft servers. But the benefits of responsible tree planting extend beyond carbon capture, notes Kroll. Soil fertility improves, meaning better food security; there's better retention of rainfall, meaning fewer floods and droughts.

"You can fix so many things through tree planting," he says. "But people don't usually see it."

However, where theory meets practice, road bumps and cautionary tales. "When I look at the global amount of tree planting, I still see a lot of projects that really fail," Kroll admits.

Billions of trees have been planted in China since 1978 to hold back the desert across close to 3,000 miles, a project dubbed the "Great Green Wall." The program has reportedly covered more than 26 million hectares -- an area bigger than the UK. But there have been mixed reports of its success.

Local people planting trees in the desert in Mingqin county, Gansu Province, China on March 28, 2019.

One 2008 study found that of all the trees planted on China's drylands since 1949, only 15% had survived . Others have reported that some areas have been planted with a single species, sometimes exotic trees that are not well adapted to local conditions and can be vulnerable to disease.

Ecosia bans single-species plantations, pesticides and non-native trees. Rather than doling out lump sums -- which, "if it fails, it fails gigantically," says Kroll -- Ecosia gradually rolls out funding to smaller partner projects, monitoring them before scaling them up. There's a large emphasis on forest maintenance and drawing on local knowledge to keep new trees alive in hostile climates (trees only count to the company total after surviving for three years).

Land cultivation in Burkina Faso to prepare the earth for saplings.

Tom Crowther, co-author of the trillion-tree study and a climate change ecologist at Swiss university ETH Zurich, describes Ecosia as an "excellent model" for incentivizing restoration.

"Ultimately, I think that money is the only thing in the way of global restoration," he adds. "We know where to do it. We know who can do it. We just need to incentivize land owners to restore ecosystems to their natural state."

Making profit the means to an end

Crowther estimates over 15 billion trees are lost globally every year, "the overwhelming majority" through deforestation, while about 5 billion are gained through regrowth. So is Ecosia's a Sisyphean task?

Other non-governmental bodies are also weighing in: The Arbor Day Foundation's Time For Trees initiative has pledged to plant 100 million trees worldwide by 2022, and Vermont nonprofit One Tree Planted aims to plant 4 million trees in 2019 on a simple $1 = one tree donation basis.

But Ecosia's holistic approach to planting is not its only contribution to sustainability; it's also adding to the debate about what a business can and should be in the 21st century.

Ecosia has planted some 75 million trees since it was founded in 2009.

Louise Baker, chief of external relations and policy at the United Nations Convention to Combat Desertification, says that when it comes to land restoration, "we can't just rely on the public sector to do this ... it is important that the private sector step up."

Ecosia's CEO believes a shakeup of the private sector is required. "The system we have at the moment is 'businesses destroy, nonprofits try to fix,'" says Kroll. "I don't think that nonprofits need to solve the problems of the world -- I think businesses naturally should."

Ecosia's economic model allows it to straddle the divide as a "self-owned nonprofit for-profit," as Kroll defines it. An external foundation has been handed shares and given veto powers should Kroll or his colleagues ever want to take money out of Ecosia, sell it or change its purpose.

Berlin-based Ecosia employs 35 people to run its business.

Kroll says Ecosia's plan for the next 10 years involves gaining a greater share of search traffic and investing in more renewable energy to cover the growing carbon footprint that incurs. It is also developing Ecosia Green Search, a tool that highlights climate-friendly brands and flags heavy polluters to help users make more sustainable choices online.

The public is ready to combat the climate emergency, he believes, pointing to a surge in Green party votes in Germany in May's European elections . "Finally, we have the response to the issue that we need. We want to support this movement and also be a role model."

"I hope we can fix capitalism to a certain extent," he adds. "All businesses should have the obligation to actually do decent business and do things that are really good for the planet and all people and be profitable at the same time."