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Ning
Zeng
Associate Professor
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In the News
Research Opportunities
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My general
research interests are in the field of climate change and climate
variability on time scales ranging from seasonal-interannual
to glacial-interglacial cycles. My approach is to study the Earth system
as a whole, focusing on the interactions among various components, in
particular, the atmosphere, the hydrosphere and the biosphere. Currently
my research covers two different but inter-connected areas: carbon
cycle-climate interaction and the modeling of
atmosphere-land-vegetation-ocean system. I also conduct research in the
technical solutions and policy implications of climate change.
Research Examples
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 Carbon
sequestration via wood burial and storage (WBS)
To mitigate global climate
change, a portfolio of strategies will be needed to keep the
atmospheric CO2 concentration below a dangerous level. I propose a carbon
sequestration strategy in which certain dead or live trees are
harvested via collection or selective cutting, then buried in trenches
or stowed away in above-ground shelters. The largely anaerobic
condition under a sufficiently thick layer of soil will prevent the
decomposition of the buried wood. Because a large flux of CO2 is
constantly being assimilated into the world’s forests via
photosynthesis, cutting off its return pathway to the atmosphere forms
an effective carbon sink. I estimated that a sustainable long-term
carbon sequestration potential for wood burial is 10 GtC/y. The cost for wood burial is lower than the
typical cost for power plant CO2 capture with geological storage. The
technique is low tech, distributed, easy to monitor, safe, and reversible,
thus an attractive option for large-scale implementation in a
world-wide carbon market. Zeng (2008). See Publication for details and
In
the News for media stories and comments.
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 Midlatitude drought and anomalous CO2 growth
A rare drought occurred from
1998 to 2002 across much of the Northern Hemisphere midlatitude
regions. Using observational data and numerical models, we
analyze the impact of this event on terrestrial ecosystem and the
global carbon cycle. The biological productivity in these regions were
found to decrease by 0.9 PgC/y or 5% compared
to the average of the previous two decades, in conjunction with
significantly reduced vegetation greenness. The drought led to a land
carbon release that is large enough to significantly modify the
canonical tropically dominated ENSO response. This large CO2
source explains the consecutive large increase in atmospheric CO2
growth rate of about 2 ppmv/y
in recent years, as well as the anomalous timing of events. Zeng,
Qian, Roedenbeck
and Heimann (2005).
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 Glacial-interglacial
Cycles
Only 21,000 years ago, large
parts of the Northern Hemisphere were covered under giant icesheets. Today, the mystery of the
glacial-interglacial cycles remains unsolved. Apart from important
roles astronomical orbital forcing may play, it is becoming
increasingly clear that CO2-climate interaction is a key component.
Zeng (2003) hypothesizes a mechanism in which organic carbon buried
under the icesheets may be a `missing link'
in the ice-age story. Zeng (2007) further proposes a mechanism where
internally generated quasi-100ky cycles could be triggered by subglacial burial carbon release as large icesheets such as the Laurentide
grow long and large enough and the basal melting ejects burial carbon
into the atmosphere, thus starting a carbon-climate-icesheet
feedback that could explain such as the deglaciation
at Termination II.
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 Drought
in the Sahel
The Sahel,
a semiarid region in West Africa between the Sahara desert and the Guinea coast rainforest, has experienced an
unprecedented drought in recorded history since the late 1960s. The
drought had a devastating impact on this ecologically vulnerable region
and was a major impetus in the establishment of the United Nations
Convention on Combating Desertification and Drought. In a perspective
article in the journal Science, Zeng (2003) explains our current
understanding of the problem.
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