The government of United Kingdom has pledged to plant millions a year while other countries have schemes running into billions.
Last year's UK general election became a contest to look green.
The Conservatives' pledge of planting 30 million trees a year, confirmed in the Budget this week, is a big step up on current rates. Critics wonder whether it's possible given that earlier targets were far easier and weren't met.
If the new planting rate is achieved, it would lead to something like 17% of the UK becoming forested, as opposed to 13% now.
Tree planting is a popular idea because forests are not only beautiful but also useful: they support wildlife, help with holding back floodwater and provide timber.
And trees absorb carbon dioxide - the main gas heating the planet - so planting more of them is seen by many as a climate change solution.
At the moment, the UK's forests pull in about 10 million tonnes of carbon dioxide a year but the hope is to more than double that.
It would involve potentially sensitive decisions about where to turn fields into forests: for example, should trees be planted where crops are grown or where cattle or sheep are grazed?
And because it can take decades to get a financial return from trees, many farmers and landowners are waiting for the government to announce new incentives.
There are machines that can do the job and even drones but people power is the tried and tested method. And good money can be earned about 7p for every tree.
For years, it's been popular among students in Canada as a summer.
To start this you'll need enough trained staff in Britain to support the government's plans for a huge increase in planting.
"You need to have the workforce to hit those numbers, which at the moment UK don't have,".Can trees stop climate change?
The answer is more complicated than you might think.
Trees use carbon dioxide as part of the process of photosynthesis with the carbon ending up in the branches, trunk and roots. But at the same time they rely on respiration, which releases some carbon dioxide.
That's why, over the years, people have described trees as "breathing" - inhaling and exhaling a flow of gases. And it turns out that understanding exactly how that flow works is extremely hard.
Prof Rob MacKenzie, of the University of Birmingham, is honest about the lack of knowledge.
"There are lots of things we don't know about the precise movement of carbon."Can trees stop climate change?
The answer is more complicated than you might think.
Trees use carbon dioxide as part of the process of photosynthesis - with the carbon ending up in the branches, trunk and roots. But at the same time they rely on respiration, which releases some carbon dioxide.
That's why, over the years, people have described trees as "breathing" - inhaling and exhaling a flow of gases..
Research so far has shown that every square metre draws in about 1,700g of CO2 every year - while also releasing up to 1,200g.
And as a forest gets older, those flows are likely to become more balanced. Prof MacKenzie says it would be a "disaster" if governments and companies rely on forests to "clear up the mess" of carbon pollution.
And he paints a grim picture of what could go wrong. "We plant lot of trees, we think we've done the job, we forget about them, and what we're left with is a really desolate dying diseased landscape that no one cares about."
Solutions
Partly, they involve choosing the right trees and partly it's about making sure that local people benefit.
In the sprawling forest of Thetford, in Norfolk, much of it planted in a rush after the First World War, Eleanor Tew has researched the best options.
Back in the 1960s and 1970s, a government-encouraged rash of planting ended up with regimented rows of the same species of conifers - which meant they were susceptible to the same pests and diseases.
Nathalie Seddon, professor of biodiversity at the University of Oxford, it's vital that forestry schemes, particularly in developing countries, aren't imposed on the people there, but instead involve them.
By contrast, a forestry scheme in northwest China successfully protected people living there from dust storms - a positive development - but the growth of the trees then led to water shortages in villages downstream.
She says: "There is an idea that you can just buy land and plant trees but that's too simplistic - there is a risk of doing more harm than good."
