At the climate change conference "COP26" held in the United Kingdom, an international framework was launched to reduce the emission of "methane", which is said to have a greenhouse effect more than 20 times that of carbon dioxide.
We agreed to set a goal of reducing by at least 30% by 2030.
At the United Nations conference "COP26", an international framework for methane reduction was launched on the 2nd at the behest of the United States and the EU-European Union.
97 countries and regions including Japan participated.
On the other hand, China, Russia, India, etc., which have high emissions, are not included.
The framework agreed to set a goal of reducing methane, which is said to have a greenhouse effect more than 20 times that of carbon dioxide, by 2030 by at least 30% compared to 2020.
"The most important thing in the next decade is to keep the global average temperature rise to 1.5 degrees Celsius and reduce methane as soon as possible," said US President Joe Biden.
Methane emissions Global situation
Methane is emitted from power generation facilities, landfills of garbage, and belching of livestock such as cows and pigs.
According to a survey by the Dutch Government's Environmental Assessment Agency, it accounts for about 18% of the world's greenhouse gases, the second highest after about 72% of carbon dioxide.
In 2019, global methane emissions will be approximately 9.83 billion tons in terms of carbon dioxide, by region, 680 million tons (6.9%) in the United States and 600 million tons in the EU = European Union. It is 10 million tons (6.2%).
Japan's emissions are 50 million tons, which is 0.5% of the world total.
On the other hand, China, which emits the highest amount of methane in the world, has 1.62 billion tons, accounting for 16% of the world total.
India, which is the second largest, has 870 million tons (8.8%), and Russia has 480 million tons (4.8%).
These three countries account for about 30%, but they have not joined this international framework.
The framework will consider specific measures to reduce emissions in the future.
Reduction of methane Japanese technology
It is said that 9% of the world's methane emissions come from paddy fields, and how to reduce it is an important issue.
There are microorganisms that produce methane in the soil of paddy fields, and methane is released into the atmosphere.
This microorganism becomes less active in the presence of oxygen.
A method called "mid-drying" that drains water from rice fields increases oxygen, suppresses activity, and suppresses methane generation.
Japan intends to contribute to the reduction of global methane emissions by applying this technology to spread the technology of repeatedly filling and draining water to Southeast Asian countries.
In an experiment conducted by a national research institute in Vietnam, it was possible to reduce methane by 35% while increasing the yield compared to the case of continuing to fill with water.
In the agricultural sector, cattle burp also emits methane.
A technology to reduce methane in burp by mixing cashew nut shell liquid with cattle feed has been developed, and a national research institute is conducting an experiment in Vietnam.
Expert "Develop a system that makes it easy for many countries to participate"
Mr. Akihiko Ito of the National Institute for Environmental Studies, who is familiar with climate change issues, commented on the background of the establishment of a new framework for reducing methane. Until now, it was treated as a minor treatment compared to carbon dioxide. However, it has become scientifically understood that the high goal of decarbonization by 2050 cannot be achieved without reducing methane. That has moved developed countries. "
In addition, he pointed out that "Russia, India, and China, which have large methane emissions, have not announced their participation in this framework so far," and should develop a system that makes it easier for more countries to participate. Is also important.
In addition, "reducing methane has a high technical hurdle, and even if new technology can be developed, funds will be required to disseminate it to developing countries," he said. I point out that it will be necessary.