Project Subjects
Long-term Global Warming Projection and Support for Adaptation
Background and Objective
There have been growing concerns about global warming since IPCC Fourth Assessment Report in 2007.
However, many uncertainties remain regarding future projections of climate change, thus reliability of futureclimate information needs to be improved in order for planning mitigation and adaptation measures against globalwarming.
In this project, we address improvement of climate model projection, i.e. reduction and quantiﬁcation ofits uncertainties. In addition, various future emission pathways are explored based upon ﬁrm scientiﬁc knowledge about climate change, reﬂecting the actual situation and future prospects of energy supply. Furthermore,
the impacts of global warming on power supply systems are being investigated based on regional scale climatechange information downscaled from global scale projections.

Main results
1. Introduction of biogeochemical process models
An earth system model, in which a global climate model is coupled to biogeochemical process models, isbeing introduced through the international collaboration with National Center for Atmospheric Research, USA.
This is to reveal the relationship between greenhouse gases emissions and climate change, and to quantify uncertainties in global warming projection. One of such biogeochemical models is the marine ecosystem model wherezoo- and phytoplankton are explicitly represented, thus the seasonal variation of ocean CO2 uptake and surface
nutrient concentrations are improved (Figs. 1 and 2) [V09006]. Using this model, the inﬂuence of iron micronutrient to primary production was numerically evaluated. We also developed an experimental technique for on-ship
incubation experiments using a natural plankton assemblage [V09006]. This is useful to investigate responses
of marine organisms to ocean acidiﬁcation, leading to further improvement of the marine ecosystem model.
Concerning terrestrial ecosystem, the impacts of climate change and/or increase of atmospheric CO2 to primary
production and water/energy balance between atmosphere and land surface were evaluated through global warming experiments using the global dynamic vegetation model.
2. Development of a simple climate model
The SEEPLUS, a web application of simple climate model, has been developed (Figs. 3 and 4) [V09016].
It is a simple tool for global warming projection with improved operability and usability. It calculates atmospheric CO2 concentration and change in globally averaged surface temperature from worldwide CO2 emissions.
One advantage of SEEPLUS is its extensive graphic function that enables users to understand important scientiﬁc knowledge such as time-delay of climate system response and uncertainty of future projections. In future,
SEEPLUS will be coupled to socio-economic models and utilized to explore various future emission pathways.
SEEPLUS will be publicly available on the CRIEPI website.
Other reports

52[V09015]

Environmental and Energy Utilization Technology
Phytoplankton
pico/naco
diatoms
diazotrophs

production

predation

egestionfunctionalization
assuming
average plankton
composition

Nutrients

remineralization

Zooplankton(adaptive)

Nutrients
aggregationmortality

remineralization
Detritus

Detritus
sinkingsinking(a) simple carbon cycle model(b) marine ecosystem modelFig. 1 Conventional ocean carbon cycle model (a) and newly introduced marine ecosystem model (b)Zoo- and phytoplankton, their production and competition are explicitly represented in marine ecosystem model.

μatm

Fig. 2 Seasonal variation of surface CO2 partialpressure (Result from marine ecosystemmodel)
Marine ecosystem model well reproduces seasonal variation in subarctic North Paciﬁc where phytoplankton growth
plays an important role.

year

Temperature change (degree C)

CO2 emission (GtC/year)

case Acase Bcase C

Fig. 3 A simple climate model application, SEEPLUS
For given inputs of CO2 emission or concentration,
SEEPLUS computes global mean temperature, its spatial
pattern and probabilistic information about climate change.

year

Fig. 4 Examples of emission pathway and corresponding temperature change calculated by SEEPLUS(left) CO2 emission pathways designed considering stabilized level of CO2 concentration and allowable CO2 emissions,(right) temporal change in globally averaged surface air temperature. The equilibrium climate sensitivity is assumed to 3
degree C, and the contribution from non-CO2 greenhouse gases is assumed about half of present day.

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