Jul. 05, 2019 06:51AM EST
Planting more than 500 billion
trees could remove around 25 percent of existing carbon from the atmosphere, a
new study has found. What's more: there's enough space to do it.
The study, published in Science Friday, set out to assess how
much new forest the earth could support without encroaching on farmland or
urban areas and came up with a figure of 0.9 billion hectares, an area roughly
the size of the U.S., BBC
News reported. That makes reforestation "the most effective solution"
for mitigating the climate crisis, the researchers concluded.
"Our study shows clearly
that forest restoration is the best climate change solution available today and
it provides hard evidence to justify investment," senior study author and
ETH-Zürich Professor Tom Crowther said, as BBC News reported. "If we
act now, this could cut carbon dioxide in the atmosphere by up to 25 percent,
to levels last seen almost a century ago."
The new trees would remove
around 200 gigatonnes of carbon, or two thirds of what humans have pumped into
the atmosphere since the industrial revolution.
New report reveals #reforestation is
one of the most effective strategies for #ClimateChange
mitigation.
We must plant more trees
, support restoration organisations and invest wisely.
>> http://bit.ly/TreePotential #TreePotential
We must plant more trees
>> http://bit.ly/TreePotential #TreePotential
However, the researchers
emphasized that tree planting was not a replacement for reducing greenhouse gas
emissions or phasing out the use of fossil fuels.
"None of this works
without emissions cuts," Crowther told Time.
Even if tree planting began
today, it would take 50 to 100 years for the new trees to soak up those 200
gigatonnes of carbon, he told The Guardian. And, as National Geographic pointed out, the researchers found that
potential tree-planting land could shrink by one-fifth by 2050 even if global
temperature rise is limited to 1.5 degrees Celsius above pre-industrial levels,
as some tropical areas could grow too hot to support forests.
Even so, Crowther said tree
planting was an important means of immediate climate action.
It's "a climate change
solution that doesn't require President Trump to immediately start believing in
climate change, or scientists to come up with technological solutions to draw
carbon dioxide out of the atmosphere," Crowther told The Guardian.
"It is available now, it is the cheapest one possible and every one of us
can get involved."
Assistant-Director General at
the UN Food and Agriculture Organization René Castro praised the study's
utility.
"We now have definitive
evidence of the potential land area for re-growing forests, where they could
exist and how much carbon they could store," Castro said, as The Guardian
reported.
To reach their conclusions,
the researchers first looked at around 80,000 satellite photographs of
protected forest areas around the world to assess the tree cover in each. They
then used Google Earth Engine mapping software to develop a model for
predicting where new trees could grow, National Geographic explained. They
found that more than half of the world's reforestation potential was located in
six countries: China, the U.S., Russia, Australia, Canada and Brazil.
However, trends are moving in
the opposite direction in Brazil, where deforestation is
on the rise under the right-wing government of President Jair
Bolsonaro. Recent satellite images show that a football-field-sized swath
of the Amazon is being lost every minute, according to National Geographic.
Bolsonaro has also been hostile to the rights of indigenous communities to the forest.
But such rights are essential for conservation:
deforestation rates are much lower in forests that recognize indigenous claims.
"We have served as
guardians of these lands for generations ... We also understand how to restore them
to health," Joan Carling, a member of the Kankanaey tribe in the
Philippines and co-convener of the Indigenous
Peoples Major Group for Sustainable Development, told National Geographic
by email. "With the security of our lands and resources, we can prevent
destructive logging, mining, agri-business, and other projects from occurring
in our territories."
Political realities are why
some scientists criticized the optimism of Crowther's findings.
"Planting trees to soak
up two-thirds of the entire anthropogenic carbon burden to date sounds too good
to be true. Probably because it is," University of Reading professor
Martin Lukac told BBC News. "This far, humans have enhanced forest cover
on a large scale only by shrinking their population size (Russia), increasing
productivity of industrial agriculture (the West) or by direct order of an
autocratic government (China). None of these activities look remotely feasible
or sustainable at global scale."
University College London
professor Simon Lewis, meanwhile, said that the amount of carbon the study said
trees would absorb was too high. He said the study had not accounted for the
carbon already in the soil before trees were planted or the hundreds of years
it would take for the trees to achieve their full storage potential, The
Guardian reported.
Plant More Trees—Young #Forests Use Carbon
Most Effectively #Treeplanting@350 @climatenews
http://bit.ly/2Umy9LD
http://bit.ly/2Umy9LD
