NEWS
The problem with
trees-for-carbon
Programmes to encourage tree-planting have been hailed as a solution in the fight to reduce
greenhouse gases and global warming. But new research* casts doubt on the likely
success of trading trees for carbon.
Current Address: SAEON
Reprinted From: http://bit.ly/37aBMej
Staff Writer
A
frica is the grassiest continent.
These grasses support birds,
reptiles, plants, insects and the
last remaining herds of large animals
that lived during the Pleistocene ep-
och – an invaluable asset for the conti-
nent and the world.
Africa’s grasslands were the cradle
of our ancestors and today are home
to more than 300 million people. But
these open landscapes could be trans-
formed if trees-for-carbon projects in-
appropriately target them for ‘restora-
tion’, according to University of Cape
Town (UCT) Emeritus Professor William
Bond, research associate of SAEON
and lead author of new research on the
topic.
“We challenge the popular view that
planting trees is a credible way of slow-
ing global warming,” says Bond.
The suggestion that Africa’s grasslands
might be transformed to forestry plan-
tations is not theoretical: the Bonn
Challenge is an example project that
proposes to ‘restore’ forest across 3.5
million square kilometres – an area cov-
ered by Europe’s 10 largest countries –
by 2030. Much of the land it’s targeting
lies in Africa.
Bond collaborated with Dr Nicola Ste-
vens and Professor Guy Midgley from
Stellenbosch University, and Dr Caro-
line Lehmann of the Royal Botanic Gar-
den Edinburgh to look critically at such
trees-for-carbon projects that propose
to forest landscapes to capture carbon
dioxide from the atmosphere.
“We found that the benefits of affores-
tation for reducing atmospheric carbon
are paltry,” he says, “while the costs to
Africa in lost land for agriculture, live-
stock, conservation, and in managing
vast plantations will have to be borne
for the foreseeable future.”
Restoration or distraction?
The researchers’ focus was the ambi-
tious AFR100 plan to plant 100 mil-
lion hectares of trees in Africa by 2030,
an offshoot of the Bonn Challenge.
That vast area – more than four times
the size of Britain – is the subject of a
pledge by 28 African countries.
Mozambique, for example, has com-
mitted to planting one million hec-
tares, South Africa to 3.6 million hec-
tares. Cameroon’s pledge requires
converting a quarter of the country to
plantations, and Nigeria’s requires al-
most one-third.
To assess the impact of AFR100, the re-
searchers looked at how much it would
cost to plant enough trees to balance
out one year’s growth in atmospheric
carbon dioxide at current rates of emis-
sions.
Their results suggest that far from of-
fering hope, such trees-for-carbon pro-
jects may be detrimental for grasslands
in Africa and distract attention from the
more urgent problem: lessening emis-
sions from fossil fuels.
Trees for carbon
We know that the amount of carbon di-
oxide in the atmosphere is increasing
by about 4.7 gigatonnes per year (1 gi-
gatonne = 1 000 000 000 tonnes).
Assuming it would cost USD10 to se-
Figure 1: Africa’s grasslands could be transformed if trees-for-carbon projects inappropriately target them for
‘restoration’ (Photo: Shutterstock)
35
Grassroots
Vol 19
No 4
November 2019