A simple solution to a complex problem.
The planet is home to three trillion trees, (far greater than NASA’s previous estimate of 400 billion), with room for another 1.2 trillion, says Dr Crowther. Speaking to CNN in April, the chief advisor to the UN’s Trillion Tree campaign spoke of the enormous capabilities of trees in absorbing carbon dioxide, the primary catalyst of climate change, and the push to ramp-up tree planting programs across the world.

The amount of carbon that we can restore if we plant 1.2 trillion trees, or at least allow those trees to grow, would be way higher than the next best climate change solution”, says Dr Crowther.

Unable to release exact figures while his research is pending publication in the Science journal, Dr Crowther cites numbers from Project Drawdown – a comprehensive action plan of 100 solutions to reverse climate change – which ranks the most effective global warming strategies by their ability to absorb carbon dioxide. The management of refrigerant chemicals, CFC and HCFC, is ranked number one on this list, with the potential to reduce atmospheric carbon dioxide by almost 90 billion tonnes.

Planting 1.2 trillion trees would give a reduction “way higher” than this, says Dr Crowther. Considering the planet’s carbon dioxide emissions measure 37 billion tonnes a year, what Dr Crowther is suggesting is a climate revolution.

So, how do trees work in reversing the effects of climate change?
The relationship between trees and carbon is essential to all life on earth – river systems, oceans, forests, animals and humans. During the carbon cycle, trees absorb atmospheric carbon dioxide and the energy from the sun, photosynthesising to release carbohydrates and oxygen. Trees can also store carbon in their trunks, branches, leaves and roots in a process called carbon sequestration.

But since the Industrial Revolution, growing amounts of greenhouse gas emissions, notably carbon dioxide, have thrown this careful sequence out of balance, occasioning in increasingly unpredictable fluctuations in the earth’s climate. The natural extremes that occur as a result of these variabilities – drought, flood, fire, cold – are expected to remain, and worsen, as human activity increases and the amounts of carbon dioxide continue to vastly outweigh the number of plants and trees that can absorb it.

This is where Dr Crowther’s trillion tree planting solution comes in. Its aim is to create a re-balance; to plant enough trees to absorb the increases in carbon dioxide, and release the building pressure of global warming on the earth’s atmosphere – before it’s too late.”

“Climate change is seen as such an immense and complicated issue – it feels like it’s seen as someone else’s problem, someone else is dealing with it or not dealing with it, and no one has a simple message for how to go about tackling it,” Dr Crowther says.

“I’d like to try and champion this as a solution that everyone can get involved in. If all the millions of people who went on climate marches in recent weeks got involved in tree planting the impact would be huge.”

Factors to consider with tree planting.
The carbon offset effects of tree planting aren’t immediate; it takes 30-40 years before a tree is mature enough to reach its carbon absorbing potential. In other words, even if 1.2 trillion trees went into the ground this year, it would be decades before we see the kind of results Dr Crowther is referring to. To address this, the climate ecologist proposes reducing or halting rates of deforestation – which currently measure 15 billion trees annually – until the newly planted trees are mature enough to cause effect.

It’s essential that the right trees are planted in the right location if Crowther’s proposed rates of climate change reversal are to be achieved. The best carbon sink tree species are fast growing and long living, with large trunk diameters, dense wood and deep root systems. Poplars, elms, oaks and pines are good options. In Australia, native trees like the Blue Mallee (Eucalyptus polybractea) are favoured in carbon offset programs due to their adaptability to drought and fire. As a rule, any tree that suits the climate and site will eventually absorb carbon; however, a mixture of exotic and native tree species will provide the enhanced benefits of canopy, windbreaks and habitat for local wildlife, in addition to carbon absorption.

The focus of any tree planting initiative should be on the revegetation of degraded landscapes and habitat restoration – not just sticking trees randomly in the ground to reach a figure for carbon offset targets.”

Serious consideration for the environment being regenerated is vital, as planting trees in unsuitable locations has the potential to cause greater harm than good. In parts of Northern Europe for example, tree planting could enhance the effects of global warming by reducing the heat and light reflected by snow. Planters should also be wary of overcrowding, as this can result in the overall poor health of all trees planted.

The ethics of tree planting in regard to responsibility of care and ownership also need to be considered, primarily: Who owns the land? Who decides what trees are planted and how? Who pays for the trees? Who looks after them once they are planted?

Who’s already involved?
In partnership with the UN and Crowther’s team of researchers, the youth led NGO, Plant for the Planet, is spearheading the Trillion Tree campaign, of which 13 billion trees have already been planted across 193 countries. But there are many other successful tree planting initiatives across the world that are taking aim at climate change reversal and regeneration.

Dozens of countries have signed their commitment to the Bonn Challenge, a global initiative with the aim to halt the loss of natural forests, begin restoration of crop lands, and bring 350 million hectares of deforested and degraded land into restoration by 2030.

Pakistan, one of the six countries who will be most affected by climate change (and also a Bonn Challenge member) has successfully reached its goal of planting a billion trees in the North-western province of Khyber Pakhtunkhwa under the Billion Tree Tsunami project; an effort to restore the area’s depleted forests while fighting climate change.

China and India have both restored over ten million hectares of deforested lands through tree planting, with China increasing its overall green vegetation area by 25% since 2000.

In the Sahara Desert, the ambitious Great Green Wall is referred to by the African Union and the UN as “Africa’s flagship initiative to combat land degradation, desertification and drought.”

Meanwhile in Australia, the government under Scott Morrison has pledged to plant 20 million native trees and understory by 2020, for the purposes of environmental conservation, community engagement and carbon reduction.

Non-for-profit initiatives are also focussed on landscape restoration and carbon emissions. Bush Heritage Australia is an organisation that aims to conserve biodiversity in Australia through buying and managing land, partnering with Indigenous groups, revegetating degraded landscapes and protecting threatened ecosystems, wildlife and plant species.

“We’ve planted more than 30,000 native seedlings at our Scottsdale Reserve in New South Wales; undertaken a major restoration project in the Fitz-Stirlings in Western Australia; and restored grasslands at Carnarvon Station in Queensland to name just a few,” says Bush Heritage Chief Executive, Heather Campbell. “This is such a critical part of our conservation vision and we’re so grateful to all of our supporters around the country who make our work possible.”

Other notable Australian revegetation and tree planting programs include Landcare, Carbon Neutral Charitable Fund, Planet Ark’s National Tree Day and Trees for Life.

1.2 Trillion Trees, or 126 Trees per person – how can you do your bit?
No matter your age, location, gender, religion, taste in music – doing your part for the climate revolution has never been so easy. The Diggers Club founder, Clive Blazey, has even worked out the math for us – 1.2 trillion trees internationally works out to be roughly 126 trees per person. And we’re going to show you just how easy it is to plant your quota (or many, many more!). So, consider this your call to arms.

Depending on whether you live remotely or in the city, the factors you need to consider will vary greatly. But keep in mind, there’s an option here to suit everyone.”

Do your research. Consider factors like the site – are there trees already growing? What kind of habitat already exists? How much room do I have? What is my climate? The end game – am I planting a wind break for livestock? A feature tree for my courtyard? Tree species – What are the best trees for carbon absorption? Native or exotic? Do I have space to increase the habitat of the area by mixing storey layers e.g. groundcover, low growing shrubs and trees?

Consider the ethics of tree planting. Who owns the land? Who is going to pay for the trees? Who is going to look after the trees after they have been planted? Is there access to water? Are the selected trees the right species for the area?

Ask the experts. If you aren’t sure where to begin, or what kind of site you’re working with, contact your local Landcare group.

Propagate. Taking cuttings or growing from seed is easy and costs virtually nothing. All it takes is a little patience and minimal skill and, pronto! You’ve got yourself some brand-new carbon munching trees. In fact, growing from trees that already exist in the area you’re planting – like eucalypts, oaks, elms, poplars – will mean your new tree babies are already acclimatised to the location and will have a greater chance of survival. There are loads of how-to’s on this, like this one here and here.

A down side to propagating can be a lack of diversity. But this is where it comes in handy to ask friends/neighbours for cuttings from their gardens, or, pack a pair of secateurs with you next time you go out exploring.

Seek out grants and funding. Local Landcare groups have a tonne of support and a number of grants available for people interested in tree planting. In rural areas, Landcare has programs like 20 Million Trees, and 10,000 trees for smaller acreage. There are local council tree planting initiatives and the opportunity for funding in urban areas too, like the Five Million Trees for Greater Sydney Grant.

Volunteer. For those low on space in their own home, like renters or inner-city dwellers, or those wanting to expand the climate revolution reach outside of their own space, volunteering at an environmental group is the way to go. Local Landcare groups and organisations like Bush Heritage and Planet Ark always need volunteers to help out.

Donate. Time, money, resources, land. There are so many ways you can contribute to the Trillion Tree initiative. You, or your workplace, can sponsor trees for planting on reserves through organisations like Trees for Life – bundles of 10x seedlings can be purchased from $35 each if you’re looking for a fun/environmentally aware gift for someone. You can go further and donate a memorial gift or bequest a part of your estate to organisations like Carbon Neutral.

Before donating, always do your research to ensure the place you are electing to gift to is reputable, respected, ethical and will use your gesture to the best of its intentions.

Now, let the tree planting revolution begin!

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Header image of tree plantings at Bush Heritage’s Scottsdale Reserve, NSW revegetation project. Image by Annette Ruzicka and supplied by Bush Heritage Australia.

You can find out more about the work being done at Bush Heritage Australia or get involved by visiting their Website, Instagram or Facebook.

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