Ciais, P., Tan, J., Wang, X.,
Roedenbeck, C., Chevallier, F.,
Piao, S.-L., Moriarty, R.,
Broquet, G., Le Quéré, C.,
Canadell, J.G., Peng, S.,
Poulter, B., Liu, Z. and Tans, P.
2019
"Five decades
of northern land
carbon uptake
revealed by
the inter-hemispheric
CO2 gradient".
Nature 568:
221-225.
NOTE:
Real-world evidence from satellites
shows a 'greening' of the Earth,
most likely caused by extra CO2
in the air.
Since 1980 the air’s CO2 content
has increased by more than 16%
( and the human population
has grown by over 55% ).
Regardless of the cause,
the 'greening' ( vegetative
enhancement, mainly in
the Northern Hemisphere ),
has increased over the
past five decades,
along with
rising CO2 levels,
and that's good news.
SUMMARY:
Ciais et al. (2019)
The fourteen researchers
examined five decades
of carbon uptake in the
Northern Hemisphere
using measurements
of the inter-hemispheric
gradient of atmospheric CO2
over the period 1958-2016.
The results of their analysis
revealed that
“the northern land sink
remained stable
between the 1960s
and the late 1980s,
then increased
by 0.5 ± 0.4 petagrams
of carbon per year
during the 1990s and
by 0.6 ± 0.5 petagrams
of carbon per year
during the 2000s”.
DETAILS:
Ciais et al. note that the
increasing land sink
of the Northern Hemisphere
“can be explained by a
combination of increasing
concentrations of atmospheric
carbon dioxide, climate variability
and changes in land cover”
during the decades of the
1960s through 1990s.
After that time (2000-2016),
they note the increase is
“underestimated by all
models, which suggests
the need for improved
consideration of changes
in drivers such as nitrogen
deposition, diffuse light
and land-use change,”
The CO2 fertilization effect,
is also undervalued by
all of the climate models.
