What if we could undo climate change by planting billions,
if not trillions, of trees? Some countries have already started to try this.
But.. What if planting trees could actually make things worse?
Forests are essential to life on earth. They are complex ecosystems that house 80% of
all terrestrial life. What’s more, it’s estimated that around 1.6 billion people
depend on forests for their livelihoods. They’re also great at soaking up carbon dioxide!
In fact, planting enough trees to cover an area slightly larger than Brazil
has the potential to remove around 200 gigatonnes of CO2 from the atmosphere.
For reference, that’s roughly five and a half times what we emitted in 2019 alone!
I know what you’re thinking. If all we have to do to stop climate change
is plant trees everywhere. Well, then... what’s the hold-up?
Well… As with most things in life, it’s actually not that simple.
Several recent studies have shown that governments and organisations need to be very
careful about what types of trees they are planting, & how they plant them,
because sometimes planting trees could actually be doing more harm than good.
Before we get into that, why don’t we start with the basics?
How do trees actually capture carbon dioxide or CO2?
Trees have skillfully evolved to use the energy of sunlight to convert carbon dioxide in the
atmosphere into sugars and oxygen. That’s how they remove CO2 from the atmosphere!
Trees keep the C from the CO2 and return the O2
to the air we breathe. The trees use this carbon to build up their leaves, branches and bark.
Forests around the world actively absorb 2.4 Gigatonnes of CO2 every single year
That’s about 7% of our total CO2 emissions for the whole of 2019!
However, it is important to remember that most of the carbon stored will eventually be re-emitted.
When trees die, worms, insects and fungi break them down.
This slowly releases the carbon that was stored inside the trees back into the atmosphere.
Therefore, as we slowly decarbonise our societies, planting more trees would
give us a little extra breathing room. But planting trees is only part of the solution.
What’s especially important is that governments and organisations plant these trees properly.
What do we mean by “properly”?
Planting only one species of tree in a given area - also known as a monoculture - can
create “ecological dead zones” with limited biodiversity and therefore weak ecosystems.
It’s also important to use species that will be more resilient to climate change,
as well as planting a variety of species to mimic the diversity of natural forests.
Similarly, if we plant trees in places that are not their natural habitat
they could become invasive. These nonnative tree species can have catastrophic consequences on local habitats.
The new trees could end up taking resources away from native trees and plants,
again reducing local biodiversity and even altering entire ecosystems.
Lastly, trees need to be planted in coordination with local communities. These are the people who
will care for and tend to the growing forest for generations to come. This ensures that
the reforestation is not just environmentally sustainable but socially sustainable as well.
In fact, studies have shown that when local communities are on board with
reforestation projects they actually have a higher likelihood of succeeding.
After all, the locals are the ones who’ll benefit the most from this.
Don’t forget that it’s always best to protect existing forests first.
This is because they absorb carbon better and are more resistant to droughts, fires and storms.
It's also important to note that forests are much more than just their trees: they are made
up of intricate networks above and below the soil that take years, if not decades, to form.
Ancient forests are particularly complex, meaning it is crucial that we protect them from deforestation.
Tree planting is…. well…. I t's complicated. We didn’t even mention how more trees might
cause heating by absorbing extra sunlight, or the interaction between greenhouse gases
in the atmosphere and the various different gases released by different types of trees.
However, if you were to remember one thing from this video,
it might be this: for tree planting to be successful,
it needs to be done responsibly, thoughtfully and in coordination with local communities.
Simply planting trees will not be enough to solve climate change in the long-term.
To do that, we need to reduce our CO2 emissions to zero.
For videos on how this could be done, consider subscribing to our YouTube channel and stay tuned.