Forest fire is a common disturbance process in forest ecosystems, which significantly affects the composition, structure and succession characteristics of forests, thereby changing the material cycle and energy flow of forest ecosystems. According to the Blue Book, between 2001 and 2022, the average annual forest burned area in the world was 46.95 million hectares, 11 times the average annual increase in planted forest area during the same period. During this period, global forest fires emitted a total of 33.9 billion tons of carbon dioxide, which can increase atmospheric carbon dioxide concentrations by 4.35 parts per million (ppm), making them a source of carbon emissions that cannot be ignored. There are obvious spatial differences in global forest fire CO2 emissions, and the CO2 emissions from forest fires in the high-latitude coniferous forests of the northern hemisphere show a rapid increasing trend.
The Global Times reporter noted that the "Blue Book" pointed out that between 2001 and 2022, Africa had the highest average annual forest fire area, about 33.32 million hectares (of which about 52% of the area was repeated fires), accounting for 71% of the global average annual forest fire area, but the forest fire area showed a downward trend year by year, and the most significant, about -210,000 hectares per year. With the exception of North America, the area of forest fires in all continents showed a downward trend.
According to the Blue Book, the frequent occurrence of extreme forest fires due to climate change and human activities is the main reason for the increase in global forest fire carbon emissions in recent years. Taking the extreme forest fire events in Canada in 2023 as an example, the forest fires emitted more than 1.5 billion tons of CO2, which is higher than the total CO2 emissions from forest fires in Canada in the past 22 years (1.374 billion tons), seriously weakening the carbon sink function of forest ecosystems. In addition, from May to August 2023, a total of 10.02 million tons of PM2.5 were emitted from forest fires in Canada, causing environmental pollution that not only affected the entire country, but also had a significant impact on air quality in vast areas of the northern hemisphere through atmospheric circulation.
As a result, the Blue Book recommends that a full-scale carbon accounting system should be established that includes natural processes. In view of the fact that forest fire has become a source of carbon emissions that cannot be ignored, it is recommended to include it in the global carbon accounting system, establish a comprehensive and scientific carbon emission monitoring and measurement system, and incorporate the risk prevention and control of forest fire carbon emissions into the carbon trading system of the carbon sink forest market.
"If forest fires are included in the global carbon accounting system, this mechanism can be used to form a 'backwards' mechanism to get countries to pay attention to prevent extreme forest fires, but to form such a mechanism, the relevant research is very complicated, so it is proposed to form an international plan for the whole world to act. Zhu Jiaojun, director of the Shenyang Institute of Applied Ecology of the Chinese Academy of Sciences and academician of the Chinese Academy of Engineering, said in an interview with the Global Times.
The Blue Book also recommends that scientific research and international cooperation on carbon emissions from forest fires should be deepened. Strengthen relevant basic research and key core technology research, build a technical system for forest fire risk identification, prediction and early warning, prevention and control, research and development of post-disaster vegetation reconstruction and rapid recovery of carbon sink technologies, and establish a unified standard forest fire carbon emission measurement and assessment system.
In addition, the Blue Book also proposes that the prevention and management of extreme forest fires should be strengthened. Forest fuel treatment and fire source control are the key measures to prevent forest fires. It is suggested that the treatment of combustible matter should be included in forest management, and the fuel load should be reduced and the intensity of forest fires should be reduced through planned fire and mechanical removal.
At the same time, Zhu Jiaojun also suggested that the composition of forest tree species should be adjusted according to local conditions, and the structural layout of the firebreak should be optimized. "How shelterbelts protect against forest fires is still a research gap, and in the future we may have to aim at a new direction to carry out fire prevention research on shelterbelts, and our main idea is to establish a 'green firebreak' in the forest where forest fires are likely to occur, and plant fire-resistant tree species, similar research has been included in our future plans." Zhu Jiaojun said.
The Blue Book also showcases China's achievements in forest fire prevention and reducing carbon emissions from forest fires. According to the Blue Book, China accounts for 5.4% of the world's forest area, but forest fire carbon emissions account for only 0.65% of the world's total forest fire carbon emissions, significantly lower than the global average. Between 2001 and 2022, China's forest fire carbon emissions showed a significant downward trend, with an average annual CO2 emission of 10 million tons.
Xu Wenru, a researcher at the Shenyang Institute of Applied Ecology of the Chinese Academy of Sciences, said in an interview with the Global Times that forest fire prevention can be achieved through scientific and effective forest fire management. China's forest fire prevention measures are very in place, and there are strict management of lighting at night, fireworks and firecrackers, littering cigarette butts, etc., and we will also strengthen the publicity of forest fire prevention and control in normal times, and deepen the public's awareness of forest fire prevention.
"China's forest fire prevention work implements the policy of 'prevention first, active elimination', and has established a relatively complete and scientific and effective forest fire early warning and monitoring system, and built a complete forest fire management network. Through vigorous investment, we have basically achieved 'early detection and early extinguishment', effectively reducing the incidence of forest fires and the carbon emissions of forest fires." Xu Wenru said that with the joint efforts of the whole society, since 2001, the number of forest fires and the area of forest fires in China have shown a downward trend as a whole, and the harm to the ecosystem and environment is gradually decreasing.
