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FOREST FIRES AND CLIMATE CHANGE

Read how climate change and forest fires are caught in a vicious, almost unbreakable cycle.

Words By Varnika Srivastava 

03/10/2021

Forest fires raging throughout the United States, Australia and many other parts of the world have killed scores of people, burned countless homes, displaced hundreds of thousands of people, and deteriorated air quality at a time when the coronavirus epidemic poses a threat to respiratory health. The gloomy skies are a foreshadowing of what is to come in a world where climate change is ignored. What seemed to be a long way off is suddenly unfolding right in front of our eyes. Wildfire risk and severity have increased as a result of climate change. Temperature, soil moisture, and the existence of trees, bushes, and other potential fuel are all elements that influence wildfire danger. All of these variables are linked to climate fluctuation and change, either directly or indirectly. Climate change has increased the drying of organic matter in forests (which ignites and spreads wildfires), doubling the occurrence of major fires in the western United States between 1984 and 2015.

Climate change, according to research, results in warmer, drier circumstances. Drought and a longer fire season are contributing to the rise in wildfire risk. For much of the United States, predictions suggest that a 1°C increase in average annual temperature would raise the median burnt area per year by 600% in some types of woods. In the Southeastern United States, modeling predicts greater fire danger and a longer fire season, with the area burnt by lightning-ignited wildfire increasing by at least 30% from 2011 by 2060. Warmer temperatures and drier conditions can help flames grow and make them harder to put out once they start— Keep in mind that people are responsible for more than 80% of wildfires in the United States.

Warmer, drier weather also aid the spread of the mountain pine beetle and other insects that weaken or kill trees, accumulating forest fuels. Wildfire danger is also influenced by land use and forest management. Climate change is predicted to exacerbate these variables, increasing the area impacted by wildfires.

Cycle of fire is hampered 

Climate change is increasing global average temperatures, resulting in prolonged droughts and cascade impacts on forests and wildfires. These effects are very location-specific, since they are influenced by the ecology of an ecosystem as well as its history of disturbances like wildfires, insect outbreaks, and logging. Increasing temperatures and droughts dry out fuels, such as dead trees and fallen branches, more quickly and fully throughout various forest types, preparing them to fire. Climate change may also diminish snowpack and speed up spring snow melt in some forests in California and British Columbia, resulting in drier vegetation and increased fire danger. Long stretches without rain in drought-stricken ecosystems, such as those in the southwestern United States, can kill trees and leave dead wood ready to fire.

Wildfires emit massive amounts of greenhouse gases into the atmosphere, which contribute to climate change. Extreme fire years in 2017 and 2018 in British Columbia each produced three times more greenhouse emissions than the province’s other industries combined. While trees can and do regenerate after a fire, the process of regenerating carbon takes time, which we might not even have.

That isn’t to argue that catastrophic flames are caused solely by climate change, nor that greenhouse gas emissions are the only result. People have created and sustained situations that enhance the danger of huge, devastating fires, particularly European colonists in North America. We are only one of many animals that have suffered as a result. In some cases, fire has actually been a key part in keeping many types of forests healthy. Lodgepole pine, for example, relies on fire to reproduce by melting resin and releasing seeds. Bans on controlled Indigenous burning and fire suppression measures in the early twentieth century disrupted the forest fire cycle and eliminated naturally occurring fires from wooded regions. The absence of fire in temperate environments has disturbed ecological mosaics and recently burnt areas, which formerly served to control fire spread and behaviour. Logging and forestry techniques such as clear cutting and replanting have altered fire danger by favouring coniferous tree stands that are virtually equal in age and may easily transport and spread fire.

Forest fires and the carbon sink

Most forests are carbon sinks, absorbing more carbon than they emit, with the quantity of carbon absorbed changing with age. Plants absorb carbon dioxide from the atmosphere and incorporate it into their leaves, roots, and biomass when they photosynthesize. This results in huge carbon stocks in forests, which are stored in plants and, most critically, soils, throughout time. Permafrost soils retain much more carbon in cold, high-latitude settings. 

Fires, as well as other disruptions, release this carbon into the atmosphere, decreasing the carbon stores that have accumulated through time. Wildfires may also diminish a forest’s potential to draw carbon out of the atmosphere, which is referred to as “sink strength.” Severe flames can also prevent forest regeneration and alter the forest’s species composition.

Wildfires increase the amount of carbon that leaves forests while decreasing the amount that comes in. While the future seems bleak, it is never too late to act. Small actions towards offsetting climate change do work. So do not let the large scale of catastrophic events stop you from doing your small bits! Most of all, talk to policy makers and politicians to persuade them to take action on a much larger scale.