The Earth has been
rapidly 'greening'
in recent decades.
In a new study published
in Nature Communications,
Max Planck Institute
for Meteorology’s
Alexander J. Winkler ,
and colleagues,
find that the 120 ppm increase
in CO2 concentration since 1850
“has resulted in enhanced GPP
[Gross Primary Productivity,
photosynthesis] due to its [CO2’s]
radiative and physiological effects.”
This new study finds models
have significantly underestimated
the actual greening effect
of rising CO2 levels.
Updating trends in satellite-observed
GPP enhancement, Winkler et al. (2019)
cite a statistically significant 52% greening
trend during 1981-2016, outpacing the
observed changes in browning (12%)
by more than a factor of four.
CO2 fertilization may explain
70% of the trend
Carbon dioxide (CO2),
an essential ingredient
in plants’ food-making
processes (photosynthesis),
has been unscientifically cast
as an atmospheric pollutant.
Many scientists, who apparently
lack an anti-CO2 political agenda,
write glowingly about the
biosphere-enriching effects
of rising CO2 concentrations.
Elevated CO2 is considered
to be the primary driver
of the observed global-scale
greening in recent decades,
especially in arid regions
where soil water
is in limited supply
Satellite observations indicate
that between 25 to 50% of the globe’s
vegetated regions are greener today
than in the 1980s, whereas less than 5%
have sustained a browning trend
(Zhu et al., 2016).
Models underestimate
the greening effects
of elevated CO2 by 60%.
The key finding of their study,
is that Earth system models
have been categorically
underestimating CO2’s
critical role in enhancing GPP.
The physiological effects
of elevated CO2 in invigorating
photosynthesis processes
( aka 'greening' ) was found to be
60% higher than previous estimates,
leading the authors to conclude:
“Our central finding is,
the effect of ambient
CO2 concentrations
on terrestrial photosynthesis
is larger than previously thought.”
Earth’s greening trends
are expected to intensify
as CO2 concentrations
continue rising.
project a ~35% increase
in global GPP (greening)
in the coming century,
or as CO2 levels reach
double (to 560 ppm)
estimated pre-industrial age
CO2 levels, believed to be
around 280 ppm.
