How is greenhouse gas emissions calculated? November 29, 13:03
Last year, the amount of greenhouse gases emitted in Japan was the smallest since fiscal 1990, when we started calculating. But invisible greenhouse gas emissions. How is it calculated?
The target is 7 kinds of gas
The United Nations IPCC = “Intergovernmental Panel on Climate Change”, which is created by scientists around the world, summarizes the guidelines, and each country decides the final formula by referring to the guidelines. That is.
There are seven types of gas, including carbon dioxide, methane, dinitrogen monoxide used for general anesthesia, and a kind of chlorofluorocarbon gas. Detailed calculation formulas are determined for each field such as the energy industry, manufacturing industry, agriculture, and waste-related fields.
Beef burp !?
Some gas from unexpected things is also included. One of them is methane produced by livestock such as cattle, pigs and sheep.
When cattle and pigs digest food in the stomach, methane is generated by the action of microorganisms and released as burps and farts. Of these, cattle are calculated according to the number of animals being bred, as well as the type and age.
For example, in the case of cows older than 1 year old raised for “beef cattle breeding”, the amount of methane produced per year is calculated to be 57 kilograms, but 1 year old raised as “beef cow” The above bull is 68.5 kilograms.
It is calculated that a “dairy cow” that can be milked at the age of 2 or older will produce 128.7 kilograms of methane. The difference between these emissions is that the amount of food to be given is the point, and information such as the number of heads, age, and type is obtained from the Ministry of Agriculture, Forestry and Fisheries.
In fiscal 1990, approximately 9.35 million tons of total livestock were emitted in terms of carbon dioxide, but as of fiscal 2017 it has decreased to over 7.28 million tons due to a decrease in the number of dairy cattle.
Soda
In addition, things familiar to life. Carbon dioxide used in carbonated drinks and dry ice.
Carbon dioxide gas is mainly a collection of carbon dioxide generated during the production of ethylene oxide used as a sterilizing agent for medical equipment and precision equipment. It means that it is accounting.
The amount of carbon dioxide from carbonated drinks and dry ice was more than 60,000 tons in 1990, but due to the increase in production of carbonated drinks about 10 years ago, it was about 80,000 tons in the five years to 2017. It is moving in.
Disposable diapers
On the other hand, paper diapers are currently under discussion. Paper diapers use petroleum-derived plastic for pulp that absorbs moisture, and it is said that more carbon dioxide than normal waste paper is produced when incinerated as waste.
For this reason, the IPCC guidelines have been revised, and the amount of paper diapers discharged has been calculated separately from paper waste for four years. The amount of carbon dioxide produced by incineration of disposable diapers is estimated to be 38,000 tons as of 1990, but since then, due to the aging of society and the increase in exports overseas, it was Has reached about 156,000 tons.
However, at a study meeting of the Ministry of the Environment that deliberates the calculation method, etc., “It is said that Japanese-made disposable diapers have a low proportion of petroleum-derived components. “The amount exported overseas is not consumed domestically and should be excluded from the calculation.”
Submit the final value to the United Nations
The amount of greenhouse gas emissions calculated in this way is checked by the expert review committee established by the Ministry of the Environment to reflect the actual situation.
This time, the preliminary figures were announced, and the Ministry of the Environment will finalize the final values around April next year and submit them to the UN through the Ministry of Foreign Affairs.