canada's forest fires released more carbon dioxide last year than russia and japan's annual carbon emissions
2024-08-30
한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina
on august 20, 2023, local time, a wildfire broke out in scotch creek, british columbia, canada, and a hotspot of the wildfire in the lower east area of adams lake was burning. visual china data map
a study by american scientists on canadian forest fires pointed out that carbon emissions from canadian wildfires in 2023 exceeded the annual emissions of seven of the world's largest fossil fuel emitters in 2022, second only to china, india and the united states, and ahead of industrial powers russia and japan.
carbon monoxide enhancement and emissions estimates from canadian wildfires.
the study shows that widespread hot and dry weather is the main cause of the fires, which has suppressed the carbon absorption capacity of canadian forests, raising concerns about whether forests can serve as long-term carbon sinks. the above results were published in the authoritative scientific journal nature on august 28, beijing time.
canada's forests are an important carbon sink in the world, absorbing more carbon from the atmosphere than they emit. these forests cover a vast area of nearly 362 million hectares, accounting for 8.5% of the world's forest area, and play an important role in absorbing carbon dioxide from the atmosphere and slowing the pace of climate warming. during 2015-2020, canada's carbon storage increased by 366±88.6 million tons of carbon per year, contributing about 30% of the net value of terrestrial carbon sinks.
however, the large carbon emissions caused by the 2023 canadian fires have called into question the sustainability of this carbon sink. the 2023 canadian fires destroyed more than 15 million hectares of forest, about 4% of canada’s total forest area, and the total area burned was seven times the average of the previous 40 years.
brendan byrne, the corresponding author of the paper, and his colleagues used an inversion model of satellite observations of carbon monoxide in smoke plumes to quantify the amount of carbon released by the fires from may to september 2023. they estimate that canada's forest fire carbon emissions from may to september 2023 reached 647 teragrams (1 teragram equals 1 trillion grams). this is far higher than the general level of forest fire emissions in canada and is comparable to india's annual fossil fuel emissions. over the past 10 years, canada's average estimate has been 29-121 teragrams, which is more than four times canada's annual fossil fuel emissions.
in addition, the study further discussed the concurrent climate anomalies and the prevalence of hot and dry weather under climate change, and pointed out that hot and dry weather is a major driver of fire activity.
the 2023 fire season in canada's forests was unusually hot and dry. this was the driest year in canada's forests from january to september since 1980, with about 86% of forest areas experiencing below-average precipitation and about 52% experiencing precipitation below one standard deviation of the 2003 to 2022 average. at the same time, may to september 2023 was the warmest since 1980, with about 100% of forest areas experiencing above-average temperatures and about 90% experiencing temperatures above one standard deviation of the 2003 to 2022 average.
the change in fire emissions as a function of temperature and precipitation z-scores between 2003 and 2023 shows a large increase in fire emissions during unusually hot and dry conditions. these hot and dry conditions were more prevalent in 2023 than in previous years, explaining why fire emissions in 2023 were so extreme.
relationship between fire emissions and climate anomalies.
2023 was the hottest year in canada in nearly four decades. but byrne and his colleagues predict that under the shared socioeconomic pathway (ssp) of moderate warming, climate warming will become a trend. by the 2050s, a large temperature increase is expected, the water cycle "accelerates", evaporation and precipitation rates increase, and the average temperature in the 2050s will be close to the 2023 level.
climate warming and an increase in regional humidity gaps could lead to an increase in carbon emissions from canadian forest fires. if large-scale fires like those in 2023 become the norm, all canadian forests could burn every 25 years. therefore, increased forest fire activity in canada could threaten the carbon absorption potential of canadian forests, making the role of forests as carbon sinks uncertain. this would further affect the allowable emissions to achieve climate warming targets, as reduced ecosystem carbon absorption must be compensated by adjusting for reductions in anthropogenic emissions.
as a party to the paris agreement, canada is obliged to track economy-wide greenhouse gas (ghg) emissions and removals in its national greenhouse gas inventory (nghgi). however, the role of canada's fire management strategy in managing carbon emissions from fires is debatable. fire management strategies need to balance multiple factors, including socioeconomic costs, ecological impacts, and carbon emissions, and canada currently uses a risk-based strategy that decides whether to suppress fires based on the specific circumstances of each fire.
the paper reporter he liping and intern shi yufei
(this article is from the paper. for more original information, please download the "the paper" app)
