TheEconomistMay21st 2022
Graphic detail Climate change
85
That non-sinking
feeling
I
f rainforestswereEarth’srespiratory
system, the Amazon would be a full lung.
The region holds half of the tropics’ undis
turbed forests. Its flora absorb 1.5bn tonnes
of carbon dioxide (CO 2 ) a year, equivalent
to 4% of emissions from fossil fuels.
This lung is being deforested at cancer
ous rates. A chunk nearly the size of Kuwait
is felled or burned every year. This both
eliminates CO 2 absorbing trees and releas
es their stored carbon back into the air.
The worst scenarios involve a tipping
point of tree loss, beyond which the forest
could no longer produce enough moisture
to sustain its ecosystem. But even if this di
saster can be averted, grave harm has alrea
dy been done to Earth’s bestknown carbon
sink. Since 2016 the Brazilian Amazon,
containing twothirds of the forest, has
spewed out more CO 2 than it has absorbed.
Two analyses from 2021 identified
chunks of theAmazon as net emitters.
One,inNature, foundthispatterninatmo
sphericsamplesfromsoutheasternAma
zonia.Theotherbuiltona paperinNature
ClimateChange, whichcombinedsatellite
images oftree losses withdata on soil
types; tree densities and ages; and the
emissions impact of landuse changes.
Based ontheresultingestimatesofCO 2
flows, authors at maap, a conservation
group,calculatedthatin200120netemis
sionsfromtheBrazilianAmazonexceeded
thoseofArgentinaorPakistan—although
thefullAmazon,includingneighbouring
countries,remaineda netcarbonsink.
Bothofthesestudiesmeasuredemis
sionsoverlongtimeperiods.Neitherre
portedwhetherrecentregionwidetrends
werepositiveornegative.Tofindout,we
matchedupthelatestdataonCO 2 flows
withyearlymapsoftreecover.
CO 2 capturehasdeterioratedslowlyand
steadily.Since 2001 theBrazilianAmazon’s
absorptionratehasfallenby1.2%a year.
Emissions,incontrast,haveoscillated.
Inthemid2000sCO 2 outputfell,asthe
centralbankcutoffcredittofirmsfacing
finesfordeforestation,andmoreforestar
easgainedlegalprotection.Butin 2012 the
governmentgrantedanamnestyforpast
deforestation,andin 2014 a recessionbe
gan,whichmayhavepushedfarmersto
seeknewland.Afternineyearsasa carbon
sink,emissionssurgedin2016,andthere
gionhasbeena netemittereversince.
Brazilhaspledgedtoendillegaldefor
estation by 2028. However, Jair Bolsonaro,
the president, has relaxed enforcement of
environmental safeguards. Satellite imag
es suggest that twice as much forest has
been lost in 2022 as the average for January
to April in 201021. The future pathofglo
bal warming depends in part onwhether
Mr Bolsonaro is reelected this year.n
The Brazilian Amazon has been a
net carbon emitter since 2016
→Deforestationleaves
a signatureinparallel
rowsofhighemissions
CruzeiroCruzeirododoSulSul
São Luís
Porto PortoVVelhoelho
RioRioBrancoBranco
BoaBoaVistaVista
Macapá
ManausManaus
MarabáMarabá
Vilhena
ColíderColíder
Cuiabá
BelBelémém
BRAZIL
BOLIVIA
PERU
COLOMBIA
VENEZUELA GUYANA
SURINAME
FRENCH
GUIANA
ATL A NTI C
OCEAN
Ama
zon
Ama
zon SantarémSantarém
-1,000
0
1,000
2,000
3,000
01234
56
Million square km
↓ A few regions with sky-high
emissions outweigh a larger
area with modest absorption
Greenhouse-gas flows,
average for 200-2
-800 -400 0 400 800
Removals Emissions
→ A surge in deforestation has turned the Brazilian Amazon into a net emitter of carbon dioxide
Greenhouse-gas flows, average for 200-2
Tonnes of CO2 equivalent per square km
Sources: “Global maps of twenty-first century forest carbon fluxes”, Harris et al.,
Nature Climate Change, 202; Hansen; UMD; Google; USGS; NASA; The Economist
Greenhouse-gas flows in the Brazilian Amazon
Tonnes of CO equivalent, bn
-1
0
1
2
2001 05 10 15 21
Emissions
Net
Removals