Summer 2019
More than 38,000 fires raged across the Amazon...
...fires that were man-made
Over the past 50 years...
...almost 17% of the world’s largest rainforest has been cleared
And globally deforestation has almost doubled in just five years
Since the start of human civilisation...
...it’s estimated that the number of trees around the world...
...has fallen by almost half
Clearing forests increases carbon-dioxide levels...
...but planting them could store away...
...some of the carbon already in the atmosphere
Everyone is looking for a silver bullet...
...to get our way out of this really difficult problem of climate change
Some people have latched on to tree planting as a kind of panacea
But the reality is tree planting is not always good
This woman runs safaris...
...in England
Guests are not only here to see wild animals...
...they’re here to see wild trees
If you could imagine when we were farming...
...back in the 1980s, through the 90s...
...this would have been a field of one particular crop as far as the eye can see
Almost 20 years ago Isabella Tree—yes that is her real name...
...handed 1,400 hectares of Sussex farmland back to nature...
...by doing, well nothing
She thinks this is the best way to use the land to help tackle climate change
Wilding is a hands-off approach
It’s become a sort of environment that is a nursery...
...for open-grown, freely regenerating trees
Within 20 years we have doubled our carbon sequestered in the soil
We’ve got the scrub, we’ve got the grasses, we’ve got the trees...
...all that will be contributing to this carbon sink
To stabilise the climate global carbon emissions...
...need to drop to net zero by 2050
Of course not all sectors are going to get down to zero emissions by 2050
Simon Lewis is a professor of global change science
We need to take some carbon out of the atmosphere...
...and one of the cheapest and easiest ways is to plant trees
Around half the dry weight of a tree is carbon
As trees grow they take carbon out of the atmosphere...
...and store it in their trunks, leaves and roots...
...which helps slow the rate of climate change
And there’s never been more global ambition to plant trees
In 2014, 51 countries pledged to plant...
...over 3.5m square kilometres of forest by 2030...
...an area slightly larger than India
Ethiopia has made its mark in the record books...
...by planting over 350m trees in a single day
The 2030 target looks likely to be met
But there’s a catch… 
When you dig down into the numbers of these forests...
...almost half the area pledged so far by countries...
...is actually from monoculture plantations
And that means a single species planted over...
...thousands and thousands of hectares
Monoculture tree plantations like eucalyptus grow quickly...
...but the trees are harvested every ten or so years...
...releasing much of the carbon stored in the tree...
...back into the atmosphere...
...which means that, according to some studies...
...they’ll store only around one-fortieth of the carbon...
...natural forests do over the long term
It’s made into short-term products like paper...
...and then when that paper is used and then discarded...
...it decomposes and that carbon goes back into the atmosphere
Simon analysed pledges from 43 countries in the tropics and sub-tropics
These big announcements are not going to deliver...
...on the carbon capture that we’re expecting
If they were all natural forests we would sequester...
...42bn tonnes of carbon this century
In fact, those pledges to plant millions of trees...
...actually promise to store 26bn tonnes less carbon than they could
Sometimes the motives for planting forests...
...are less green than they might appear
By 2020 Ireland ought to have cut greenhouse-gas emissions...
...by 20% below 2005 levels
But at current rates it will have reduced them by only 5%
Planting forests might help Ireland avoid massive penalties...
...for missing EU targets...
...because the potential carbon these forests could store in the future...
...can be counted as a carbon credit today
In the 1920s Ireland had the lowest forest cover in Europe at around 1%
That’s now risen to 11% and the government has set a target...
...to cover 18% of the land with forest by 2046
In Ireland, they’re rapidly increasing the amount of forest cover
But it’s overwhelmingly going towards monoculture plantations of conifers
And now local community groups are protesting against...
...these monoculture tree plantations
They say they’re doing more harm than good
Because these monoculture plantations are about getting...
...the maximum yield as fast as possible they often apply fertilisers...
...which contribute to greenhouse gas nitrous oxide
Conifer plantations are very densely stocked...
...so cut out almost all the light...
...are very poor for biodiversity and can really affect people living nearby
Tree-planting programmes invariably have an impact...
...on the people living nearby
In east Africa one project is demonstrating what can be achieved...
...when there’s genuine buy-in from the local communities
Green Ethiopia is a mixed-tree planting charity
We plant seedlings in rural areas of Ethiopia...
...that is heavily affected by degradation due to deforestation
The land is communally owned...
...and co-operatives of local women receive benefits for planting trees...
...which are protected from being harvested
Empowering the local community on tree planting...
...contributes a lot for the sustainability of our forestation activities...
...because it creates a sense of ownership
The local communities strongly participate...
...in planting, managing and conserving the sites
Here conserving is just as important as planting
Green Ethiopia assesses whether the condition of the land...
...is good enough to regenerate by itself
When it is—on about a third of the area the charity runs...
...they leave it alone
Just like Isabella Tree, back in England
Perhaps the right way to think about tree planting is...
...just leave the land and it can do it spontaneously itself
There is no need for interventions by humans in most cases
But this approach brings its own challenges
The problem with this kind of natural regeneration is that...
...it’s very difficult to get funding
The funding is all driven by targets...
...the numbers game
In a regenerated landscape like this...
...we can’t have any idea of how many oaks there’ll be...
...or how many crab apples will come
Monoculture plantations are often preferred because they make money
So some experts are looking to a future where...
...carbon payments could create financial incentives for natural forests
If carbon becomes much more important as a commodity...
...then perhaps these natural forests would become...
...more profitable than plantations
There’s a real opportunity here to shift the incentives...
...towards getting benefits for the climate...
...and benefits for local people and benefits for local wildlife
Ultimately though, the trouble with trees tackling climate change is space
There’s just not enough land in the world to plant enough trees...
...to offset all the carbon emissions from fossil fuels
We could say let’s restore forest on every single piece of land...
...that used to have forest on from before agriculture
And if we did that it would be about 200bn tonnes of carbon
Now that sounds a lot but to put it in context...
...that’s about 20 years’ worth of emissions at present rates
Tree planting might be looked at as a saviour
But it’s not
It’s not an excuse not to cut fossil-fuel emissions
