Cause of Global Warming
《Point》 Global warming is caused by anthropogenic activities.
7000
Gas
CO2 Emission by fuel
6000
Oil
Fossil fuel consumption is increasing
rapidly to satisfy growing energy demand
CO 2 emissions (MtC/yr)
5000
Coal after the Industrial Revolution, which
4000
started at the end of the 18th century.
3000 Fossil fuel combustion ：
2000 C + O2 → CO2
（Carbon in （Oxide in
1000 Fossil fuel） Atmosphere）
375 1
0
Historical CO2 record from the Siple Station ice core
1750 1800 1850 1900 1950 2000
Atmospheric CO2 record from Mauna Loa
Year
concentration
Global mean temperature change
350 Global mean temperature relative to the mean of 1961-1990 0.5
Source: Carbon Dioxide Information Analysis Center, ORNL
（ppmv）
2
（℃）
Atmospheric CO 325 0
Atmospheric CO2 Concentration
and Global mean Temperature 300 -0.5
Atmospheric CO2 concentration and
global mean temperature increase with 275
1750 1800 1850 1900 1950
-1
2000
the rapid increase of CO2 emission. Year
Source: Carbon Dioxide Information Analysis Center, ORNL
Carbon Cycle
《Point》 Carbon（C） circulates on the Earth.
The carbon (C) circulates among
terrestrial plants, the atmosphere
and the ocean, undergoing various
reactions.
For example,
Solution
： CO2 + H2O ⇄ 2H+ + CO32-
Photosynthesis
： 6CO2 + 6H2O → 6O2 + C6H12O6
However, anthropogenic activities
like fossil fuel burning and
deforestation have released carbon
(C) to the atmosphere and have
increased the carbon in the
atmosphere.
Burning ： C + O2 → CO2
This carbon increase in the atmosphere
leads to the global warming.
Greenhouse Effect
《Point》 CO2（carbon dioxide） plays an important role
to keep the earth warm.
Greenhouse gases, e.g., CO2,
absorb infrared radiation,
while solar radiation passes
through gas layer.
Certain amounts of greenhouse
gases (CO2 etc) are necessary to
keep the earth warm.
Global Warming
《Point》 However, increase in atmospheric concentration
of CO2 causes global warming.
CO2 increase in the
atmosphere “thickens”
the infrared radiation
absorption layer.
The “thicker” absorption layer
keeps the earth warmer.
Projection of Climate Change
《Point》 CO2 concentration increase causes the rises of
the global temperature and sea level.
Temperature rise of 1.4 deg.C at
the lowest and 5.8 deg.C at the
Temperature Change highest is projected in case of no
CO2 emission reduction.
Sea level Change
Source: The Third Assessment Report by Intergovernmental
Panel on Climate Change(IPCC)
Sea level rise of 0.1m at the lowest
and 0.9m at the highest is projected
in case of no CO2 emission reduction.
Source: The Third Assessment Report by Intergovernmental Panel on Climate Change(IPCC)
Global Warming Impacts
《Point》 Extraordinary weather is projected to occur
in various world regions.
CO2 Emission
《Point》 CO2 emissions vary widely across countries.
・CO2 emissions and per capita emissions are large at present for developed countries.
・CO2 emissions in developing countries are projected to increase with the population
and the economic growths.
Global Warming Mitigation
《Point》
We have various
mitigation options to
reduce CO2 emissions.
A cost-effective
combination of the
options is required.
Global Warming Mitigation Scenario
《Point》 Economic consideration is important to
select a combination of the options.
25
Energy Saving Without CO2 mitigation policy ...
Fuel Switching among Fossil Fuels Energy Saving
Nuclear Power
CO 2 emission and reduction (Gton of carbon eq.)
Effective CO 2 reduction by these technologies.
Renewable Energy Fuel Switching among
20
Fossil Fuels
Geological Sequestration (Depleted Gas Well)
Nuclear Power
Geological Sequestration (Aquifer)
Ocean Sequestration
Renewable Energy
15 Forestation
Net CO2 Emission
Geological Sequestration
(Depleted Gas Well)
Geological Sequestration
10 (Aquifer)
Ocean Sequestration
5
The CO2 emission level is required to stabilize the double of the Forestation
pre-industrial atmospheric CO2 concentration (550 ppmv).
0
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
Year
