Special Issue

Global Warming Issues

Futurs Scope of Its Technological Options

Review

Global Energy Prospects in the 21st Century

Kenji YAMAJI (Electrical Engineering Dept. Tokyo University)

Abstract
Through model analyses of CO₂ emissions reduction measures which have the least cost over the long term from a global standpoint, the following two important points become evident.

The first point is that if the goal is to stabilize the CO₂ concentration in the atmosphere over the long term, say, at 550 ppm in 2100, then CO₂ emissions should not be cut immediately over the short term.

Rather, the optimum measure would be to wait for the fruits of technology development and to dramatically reduce CO₂ emissions from the middle of the 21st century.

However, taking no action at present in anticipation of the future reduction of CO₂ emissions can hardly be justified.

Adequate investments in technology development must be made now to prepare for the future. The second point is that there are numerous low-cost reduction measures in developing countries. Generally speaking, developing countries abound with solar energy, boast favorable conditions for cultivating biomass resources, and have ample room for improving the efficiency of energy utilization.

These features give significance to the "joint implementation" projects.

Key words : Global Energy Model, CO₂ Mitigation, Energy Technology Assessment, Joint Implementation, Long-range R & D:

(Language:Japanese)

Review

Research and Development of Technologies Responding to Global Warming/Climate Change

Takashi IBUSUKI (Atmospheric Environmental Protection Department NIRE)

Abstract
Reduction of greenhouse gases (especially carbon dioxide) causing global warming or climate change, is closely connected with restriction of fossil fuels/energy use, and thus, affects the industrial and economical activities of every country throughout the world. Technological responses to this reduction are classified roughly into energy related options and CO₂ mitigation ones. The former includes research and development projects for improved efficiency of energy utilization at both production/supply and consumption/demand sides as well as those for fuel switching. The latter consists of R & D projects for CO₂ reutilization and CO₂ sequestration. In this report, R & D activities for the technologies and the time of practical application of the technologies are being reviewed.

Key words : Climate change, Mitigation technologies, Efficient energy use, Renewable energy, CO₂ sequestration

(Language:Japanese)

Review

CO₂ Emission Reduction Potential by Energy Conservation Technology Development in Combustion and Thermal Energy Utilization

Masakazu YAMAZAKI (Thermal Energy and Combustion Engineering Department, Thermal Energy Applications Division, NIRE)

Abstract
To cope with the global warming problem, Japan has proposed a technological strategy "New Earth 21", in which the required technological options for reducing CO₂ emission are nominated and the effects of CO₂ reduction brought by each option are evaluated. Among the possible options, technology development for energy conservation is recognized as the most important because of its immediate and reliable effect on CO₂ emission reduction.

This paper reviews the present situation and future prospects of the development of the principal energy conservation technologies in the field of combustion and thermal energy utilization, such as advanced power generation (combined cycle, fuel cell, coal gasification combined cycle), refuse incineration for power generation, advanced combustion technologies for industrial use (regenerative combustion, oxygen combustion) and systematic energy utilization (cogeneration, broad area energy utilization network system).

Key words : CO₂ emission, Energy conservation, Combustion, Thermal energy utilization

(Language:Japanese)

Review

Present state and problems of the technology for utilizing geothermal and other natural energy.

Isao MATSUNAGA (Mining and Geotechnology Department, Geo-Energy Division, NIRE)
Hugh MURPHY (Institute for Resources & Environmental Geosciences, Colorado School of Mines.)

Abstract
Since natural energy such as geothermal, wind, and solar, emit much smaller amount of CO₂ gas than from the burning of fossil fuels, the usage of those energy is very effective for depression of CO₂ emission. Over 500 MW of electricity has already been generated at geothermal power plants in Japan.

However further R & D efforts will be required to introduce those energy with high cost into the commercial market.

In this paper we introduce at first the energy flows and relations among each energy in the earth. Then we review the state of each energy utilization and technology needed for developing those energy.

Key words : energy flows, renewable energy sources, geothermal energy, solar energy, wind power

(Language:Japanese)