COMON SENSE(Ⅱ) Misunderstanding issue

If we don’t exclude water vapor as a greenhouse gas, we’ll notice other problems as well. Example 1) Comparison of coal-fired and LNG-fired power plants From the perspective of preventing global warming, coal may be superior to LNG. Assuming that the main component of coal is C (carbon) and the main component of LNG is CH4 (methane),

*Chemical formula for LNG combustion: CH4 + 2O2 → CO2 (molecular weight 44) + 2H2O (molecular weight 36) + E (calories) … Equation 1 Since water vapor (H2O) has a greenhouse effect 5 to 10 times (average 7.5 times) that of CO2 per unit weight, the greenhouse effect of the exhaust gas on the right side of Equation 1, in CO2 equivalent, is 1CO2 + 7.5 × 36 / 44CO2 = 7.1CO2

*Chemical formula for coal combustion: C + O2 → CO2 + 1/2E (calories) … Equation 2 The above Equation 2 is created under the condition that coal generates twice as much CO2 as LNG to obtain the same energy E (calories).

Doubling both sides of the equation so that the generated energy is the same as in Equation 1 (calories E), we get: 2C + 2O2 → 2CO2 + E (calories) … Equation 3 (CO2 equivalent: 2CO2) Comparing LNG (Equation 1) and coal (Equation 3), calculations show that LNG emits approximately 3.5 times more greenhouse gases than coal (7.1CO2 ÷ 2CO2). This contradicts the common idea that “coal-fired power plants emit twice as much greenhouse gas (CO2) as LNG-fired power plants to obtain the same amount of energy.” The international consensus to reduce coal-fired power plants may also need to be reconsidered. At the G7 Climate, Energy and Environment Ministers’ Meeting held in Turin, Italy at the end of April 2024, an agreement was reached to phase out coal-fired power plants that have not implemented CO2 emission reduction measures in G7 countries by 2035, citing that “coal is the biggest emitter of carbon dioxide (CO2) among fossil fuels.”

Japan, which has the highest proportion of coal-fired power generation among developed countries, had resisted the trend towards phasing out coal at previous G7 meetings, but was ultimately overruled. Japan should be able to dispel potentially incorrect preconceptions about coal-fired power and proudly set an example for the world with its advanced coal-fired power generation technology. At the same time, it goes without saying that further improvements in technologies to suppress the emission of polluting gases during coal combustion are necessary. While efforts to reduce dependence on fossil fuels such as oil, LNG, and coal, which will eventually disappear, and promote renewable energy are necessary, coal is inexpensive and may be superior to other fossil fuels from the perspective of preventing global warming.

Example 2) Are hydrogen fuel cells ineffective in preventing global warming?

Hydrogen vehicles do not emit CO2, but they do emit water vapor, a powerful greenhouse gas, so they may not be effective in combating global warming. Chemical formula: H2 + 1/2O2 → H2O (emitted as water vapor)

Ideally, measures such as capturing the water vapor after cooling should be considered to prevent its emission. *This applies if the goal is to reduce greenhouse gas emissions.

(Other Issues) Regarding the idea that nuclear power should be promoted because it doesn’t emit CO2 and is therefore effective in preventing global warming.

Japan has a plan to increase nuclear power from 6% to over 20% by 2030.

Can we really say it’s good just because it doesn’t emit CO2?

The rise in seawater temperature due to the large amount of warm wastewater discharged from nuclear power plants, marine pollution, and the problem of radioactive waste disposal must also be considered.

Power generation efficiency is 33%-35% for nuclear power, 40% for coal-fired power plants, and 50% for LNG-fired power plants.

Nuclear power plants release 65% of the thermal energy they generate into the environment. How significant will this be in terms of environmental impact, such as rising seawater temperature and radioactive contamination?

Uranium, the fuel for nuclear power, will be depleted in about 100 years, just like fossil fuels.

It is said that coal will last 130 years, uranium 128 years, natural gas 49 years, and oil 54 years.

Thermal power generation may be superior to nuclear power generation in terms of economics, environmental impact, and safety.

The forceful promotion of renewable energy is leading to soaring energy costs, and consequently, inflation. Furthermore, the easy promotion of nuclear power, despite unresolved issues such as radioactive material disposal, is being masked by this trend. In Japan, while there was strong opposition to nuclear power until recently, there seems to be a growing trend towards accepting it.

I don’t reject nuclear energy as an energy source, but the idea that it doesn’t emit CO2 may be meaningless. Addressing the environmental impact should take priority.

Promoting the introduction of renewable energy such as solar and wind power in a manageable manner, while utilizing low-cost coal-fired power plants for the time being, might be a wise choice.

We should carefully compare and consider the ideal composition of our power generation systems.

Some solar scientists suggest that global warming is caused by fluctuations in natural forces such as the sun.

I recently learned about the research findings of Professor Hiroshi Tanaka, Professor Emeritus of Tsukuba University. He warns that conventional average temperature data on global warming is influenced by the urban heat island effect, and that if this effect is removed, the cause of the rise in average temperature is minimal and can be adequately explained by changes in solar activity. I was deeply impressed when I read the research findings and message he shared upon his retirement from the university two years ago.