Global Warming―Cause, Impact and Mitigation ―Observation of Climate Change《Point》

Global warming is caused by anthropogenic activities.
CO2 Emission by Fuel Type
Fossil fuel consumption is increasing rapidly tosatisfy growing energy demand after theIndustrial Revolution, which started in the late
18th century.
Fossil fuel combustion ：C+O2→
CO2（Carbon inFossil fuel）（Atmospheric Oxygen )Source: Carbon Dioxide Information Analysis Center, ORNL

Atmospheric CO2 Concentration andTemperature Rise
Atmospheric CO2 concentration and global
mean temperature are increasing along withthe rapid increase of CO2 emission.
Source: Carbon Dioxide Information Analysis Center, ORNL

Carbon Cycle《Point》 Carbon（C） circulates in the earth.
The carbon (C) circulates among terrestrial
plants, the atmosphere and the ocean,undergoing various reactions.
For example,
Solution in the ocean :CO2 + H2O ⇄ 2H+ + CO32Photosynthesis :6CO2 + 6H2O → 6O2 + C6H12O6

However, combustion of massive fossil
fuel is causing a release of undergroundcarbon (C) to the atmosphere anddisrupting this cycle.
Combustion ： C + O2 → CO2
This carbon increase in the atmosphereleads to the global warming.

Greenhouse Effect《Point》 CO2（carbon dioxide） plays an important role tokeep the earth warm.
Greenhouse gases like CO2 absorb
infrared radiation (heat), whileletting sunlight go through itself.

Appropriate amounts of greenhousegases (such as CO2) are reflecting
infrared radiation (heat) back to theearth to keep it warm.

Global Warming《Point》 However, increase in atmospheric CO2 concentration iscausing global warming.
CO2 increase in the atmosphere“thickens” the infrared radiationreflection layer.

The “thicker” reflection layer iskeeping too much heat around theearth.

Projection of Climate Change《Point》 Continuing current increase of CO2 concentration causes
the rises of the global temperature and sea level.
Projection ofTemperature Rise

If no action is taken towards CO2
emission reduction, projected
temperature rise in 2100 is 1.4 deg.C at aminimum, and 5.8 deg.C at a maximum.

Projection ofSea level Rise

Source: The Third Assessment Report by Intergovernmental Panel on
Climate Change(IPCC)

If no action is taken towards CO2 emission
reduction, projected sea level rise in 2100
is 0.1m at a minimum, and 0.9m at amaximum.
Source: The Third Assessment Report by Intergovernmental Panel on Climate Change(IPCC)

Global Warming Impacts《Point》 Extreme weather events are projected to occur invarious regions worldwide.

CO2 Emission《Point》 CO2 emissions vary widely across countries.

*) Total amount of 6 GHGs including CO2 or CH4 {CO2 equivalent}・Currently emissions from China and U.S. are notably large.
・In the future, GHG emissions are projected to increase from developing countries, due to their population increase andeconomic growth.
・Emissions per unit of GDP (GHGs emitted per 1-unit production of GDP) are small in developed countries, and large indeveloping countries.

Global Warming Mitigation《Point》
There are various
countermeasures toreduce CO2 emissions.
Unless they areimplemented in
combination, global
warming shall not beconstrained.

Global Warming Mitigation Scenario《Point》 Economic consideration is important inselecting a combination of the countermeasures.
25
Without global warming countermeasures ...

CO2 emission and reduction (Gton of carbon eq.)

Fuel Switching among Fossil Fuels

Energy Saving

Nuclear Power

20

Fuel Switching amongFossil Fuels

Renewable Energy
Geological Storage (Depleted Gas Well)

Nuclear Power

Geological Storage (Aquifer)
Ocean Storage

15

Renewable Energy

Forestation
Net CO2 Emission

Geological Storage(Depleted Gas Well)
Geological Storage(Aquifer)10

Ocean Storage

5Forestation

The CO2 emission level is required to be stabilized at the twice of thepre-industrial atmospheric CO2 concentration (550 ppmv).

02000

2010

2020

2030

2040

2050
Year

2060

2070

2080

2090

2100

Effective CO2 reduction by these technologiesEnergy Saving