CURRENT APPROACHES TO QUANTIFYING THE NEW ZEALAND TERRESTRIAL CARBON BUDGET
Description: New Zealand (NZ) is developing a system to quantify the national
inventory of C stocks and changes in vegetation and soils, in order to meet its
obligations under the UN Framework Convention on Climate Change (FCCC) and
Kyoto Protocol. The current system applies an inventory-based approach applied
to forests, shrublands and agricultural lands. Our approach emphasizes
assessment of vegetation and soil C stocks, and changes due to afforestation
and reforestation since 1990, as these activities represent an important
component of NZ’s greenhouse gas inventory.
All estimates are based on the national Land Cover Database (LCDB),
which is repeated through satellite remote sensing at ~5 year intervals, with
current estimates based on 1996/7 and 2001/2.
The current measurement-based approach for forest and shrubland biomass
uses historical national datasets for indigenous and exotic forests, and
defines remeasurement of plots on a national grid for both forest types. We
highlight current research to develop complementary model-based approaches to
estimating C stocks and fluxes for both vegetation and soils, to support
forecasting and in anticipation of more rigorous future reporting requirements.
Development of a regional- to national-scale vegetation model presently centres
on a simple partially-constrained light-use efficiency approach with spatial
representation of the primary growth limiting factor. More complex models,
involving multiple environmental constraints and detailed physiological
modelling of leaf-to-canopy processes within a multilayered canopy, provide a
robust basis for estimation of parameters in the simple model. We currently use
an IPCC tier-2 methodology for predicting soil C changes based on land-use
categories, climate, soil class, and topography. The system assumes soil C attains a steady
state under stable long-term land use and that differences between the
steady-state C stocks under different land uses define the changes in soil C
that result from land-use change.
Current research aims to estimate rates of change using long-term data
from sites of known land-use change and management history and natural
abundance radiocarbon-based estimates of soil C pools and turnover rates. Present estimates suggest New Zealand’s
“Kyoto forests” sequester ~6.2 Mt C y-1, with a concomitant soil C
loss of 0.7±0.3 Mt C y-1.
Author's Names: W.T. Baisden, A.S. Walcroft, C.M. Trotter, et al.
Filesize: 19.41 Kb
Added on: 25-Jul-2005 Downloads: 36
Home Page | Comment on Proceeding | Details
MULTI-CENTURY CHANGES TO GLOBAL CLIMATE AND CARBON CYCLE: RESULTS FROM A COUPLED CLIMATE...
Description: In this paper, we use a coupled climate and carbon
cycle model to investigate the global climate and carbon cycle changes out to
year 2300 that would occur if CO2 emissions from all the currently
estimated fossil fuel resources were released to the atmosphere. By year 2300,
the global climate warms by about 8 K and atmospheric CO2 reaches
1423 ppmv. In our simulation, the prescribed cumulative emission since
pre-industrial period is about 5400 Gt-C by the end of 23rd century.
At year 2300, nearly 45% of cumulative emissions remain in the atmosphere. In
our simulations both soils and living biomass are net carbon sinks throughout
the simulation. Despite having relatively low climate sensitivity and strong
carbon uptake by the land biosphere, our model projections suggest severe
long-term consequences for global climate if all the fossil-fuel carbon is
ultimately released to the atmosphere.
Author's Names: G. Bala, K. Caldeira, A. Mirin, M. Wickett, and C. Delire
Filesize: 43.26 Kb
Added on: 25-Jul-2005 Downloads: 44
Home Page | Comment on Proceeding | Details
EFFECTS OF VERTICAL DIC DISTRIBUTION ON STORAGE EFFICIENCY OF DIRECT INJECTION OF CO2 INTO THE OCEAN
Description:
We estimated the effects of initial
vertical distribution of dissolved inorganic carbon (DIC) on storage efficiency
of direct injection of CO2 into the ocean. Our simulations shown
that the storage efficiencies could be reduced up to 10% if a relative large
droplet (30 mm in diameter) was injected at depth of 1500m. The storage
efficiency of CO2 ocean sequestration is strongly related with not
only injection depth but also the initial CO2 droplet diameter. With
a given injection rate, the larger droplets injected will produce a dilute DIC
plume and thus improve the acute biological impacts but a smaller storage
effective due to droplet ascending.
Author's Names: Baixin Chen, Masahiro Nishio, and Makoto Akai
Filesize: 204.22 Kb
Added on: 28-Jul-2005 Downloads: 156
Home Page | Comment on Proceeding | Details
“USABLE” CARBON CYCLE SCIENCE: EXPLORING THE NEXUS OF CARBON CYCLE SCIENCE AND CARBON ...
Description:
To
date there has been little systematic research on how carbon cycle scientific
information will be used to support decisions at various scales. There is therefore a strong need to begin to
understand how carbon cycle science is currently being used, who potential
users might be, and how to effectively engage stakeholders and scientists on
the issue. Many assumptions are being
made about the scales and information that will be of most use to
decision-makers. Decisions and
information flow do not necessarily translate between scales, and thus matching
the scales between provision of scientific information and scale of
decision-making is critical to effectively making information useful. This paper will examine the ways in which
carbon is being or may be managed by users at various scales, characterize
decision making processes of those users, and discuss implications for carbon
management and science policy.
Author's Names: Lisa Dilling
Filesize: 25.79 Kb
Added on: 28-Jul-2005 Downloads: 49
Home Page | Comment on Proceeding | Details
GREENHOUSE GAS BUDGET OF NEWLY ESTABLISHED GRASSLANDS
Description:
A field experiment on the Swiss Plateau was
designed to measure the greenhouse gas (GHG) budget of two parallel fields
after conversion from arable crop rotation to cut grassland and managed either
intensively or extensively. Measurements of N2O fluxes with chambers
and of CO2 with eddy flux towers were complemented by estimates of
C-imports (organic fertilizers) and C-exports (yield). The results indicate
that newly established grassland plots act as a net GHG sink when management
intensity (fertilization and cutting) is high, while conversion to extensive
grasslands leads to an initial net loss of GHG.
Author's Names: J. Fuhrer, C. Ammann, C. Flechard, J. Leifeld, et al
Filesize: 594.13 Kb
Added on: 28-Jul-2005 Downloads: 35
Home Page | Comment on Proceeding | Details
LIMITS OF IRON FERTILIZATION
Description:
Iron
fertilization has been proposed as a cheap, controllable, and environmentally
benign method for removing carbon dioxide from the atmosphere. While this is in
fact the case in simple, 3-box models of the carbon cycle, more realistic
models show that these claims fall short of reality. The fact that the
efficiency of iron fertilization depends on the long term fate of the added
iron and on the carbon associated with it makes tracking the effects of iron
fertilization much more difficult and expensive than has been asserted.
Additionally, advection of low nutrient water away from iron-rich areas can
result in lowering production remotely, with potentially serious consequences.
Author's Names: Anand Gnanadesikan, John P. Dunne and Irina Marinov
Filesize: 17.55 Kb
Added on: 29-Jul-2005 Downloads: 49
Home Page | Comment on Proceeding | Details
PROCESSES AND DIFFUSION NEAR A LIQUID CO2 – SEAWATER INTERFACE
Description:
If liquid CO2 is stored as a dense "lake" on the
deep ocean floor, it is expected to dissolve in seawater. Ocean currents and
turbulence may increase the net rate of CO2 release by several orders of magnitude compared to
molecular diffusion. However, density stratification in the seawater created by
dissolved CO2 will
tend to reduce vertical mixing. By comparing results from different model
formulations, this study aims to increase our understanding of the processes in
such a layer of CO2-enriched
seawater, and decrease the uncertainties about storage efficiency and
subsequent environmental impact. The study is also relevant to the case of
saturated water leaking from subseabed geological storage through bottom
sediments.
Author's Names: Lars Inge Enstad, Peter M. Haugan and Guttorm Alendal
Filesize: 130.35 Kb
Added on: 29-Jul-2005 Downloads: 37
Home Page | Comment on Proceeding | Details
METRICS TO ASSESS THE MITIGATION OF GLOBAL WARMING BY CARBON CAPTURE AND STORAGE
Description:
Different metrics to assess
mitigation of global warming by carbon capture and storage are discussed. The
climatic impact of capturing 30% of the anthropogenic carbon emission and its
storage in the ocean or in a geological reservoir are evaluated for different
stabilization scenarios using a reduced-form carbon cycle-climate model. The
accumulated Global Warming Avoided (GWA) remains, after a ramp-up during the
first ~50 years, in the range of 15 to 30% over the next millennium for deep
ocean injection and for geological storage with annual leakage rates of up to
about 0.001. For longer time scales, the GWA may approach zero or become negative
for storage in a reservoir with even small leakage rates, accounting for the CO2
associated with the energy penalty for carbon capture. For an annual leakage
rate of 0.01, surface air temperature becomes higher than in the absence of
storage after three centuries only.
Author's Names: Peter M. Haugan and Fortunat Joos
Filesize: 113.31 Kb
Added on: 29-Jul-2005 Downloads: 134
Home Page | Comment on Proceeding | Details
THE ROLE OF CARBON DIOXIDE IN CLIMATE FORCING OVER THE PAST 26 YEARS
Description: Air samples are
collected through the Climate Monitoring and Diagnostics Laboratory (CMDL) global network, including a cooperative
program for the carbon gases which provides samples from about 100 global clean
air sites, including measurements at 5 degree latitude intervals from three
ship routes. Greenhouse gas concentrations are analyzed in terms of the changes
in radiative forcing during the 26-year period encompassing 1979 through 2004.
The growing fraction of the total radiative forcing due to carbon dioxide is
emphasized and the nature of the interannual variations in the radiative
forcing is explored. The interannual change in total radiative forcing is used
to define an Annual Greenhouse Gas Index (AGGI).
Author's Names: D.J. Hofmann, J.H. Butler, E.J. Dlugokencky, et al
Filesize: 40.80 Kb
Added on: 29-Jul-2005 Downloads: 32
Home Page | Comment on Proceeding | Details
ASSESSING THE EFFECTIVENESS OF SOIL CARBON SEQUESTRATION IN NORTH AMERICA AND ITS IMPACT ON ...
Description:
Soil carbon sequestration has been
shown to be an important part of a portfolio of carbon sequestration strategies
in the U.S. and Canada,
and one that can be implemented at relatively low costs [McCarl and Schneider, 2001]. The purpose
of this analysis is to estimate the soil carbon sequestration potential in the
North America (Canada and United States)
and its impact on net terrestrial CO2 uptake over the period 1981-2000.
Author's Names: A.K. Jain, X. Yang, T.O. West, W.M. Post
Filesize: 26.89 Kb
Added on: 29-Jul-2005 Downloads: 49
Home Page | Comment on Proceeding | Details