Large-scale forest fires caused by climate change are occurring with increasing frequency around the world, causing a marked deterioration in air quality and increasing the associated health risks in Estonia.
"Extensive landscape fires are getting worse worldwide," a climate scientist told ERR. He said global warming has increased the intensity and frequency of heat waves almost everywhere on earth, including northern Europe and Estonia. The same has been true for droughts across many regions.
"Landscape fires erupt when the weather is hot and dry, and high winds promote fire spread. There is indeed a direct causal relationship between climate change and warming," the climate scientist said. Global warming is already causing more frequent and severe heat waves and droughts, which increases the likelihood of landscape fires.
Toll pointed out that although the Earth's climate has warmed by approximately one degree since the industrial revolution, the average temperature could rise by an additional three degrees by the end of the century if greenhouse gas emissions are not reduced. "With the onset of El Nino affecting global weather patterns, this will also have a clear impact on wildfires in the coming years," he added.
Siberian fires threaten Estonia's air
Toll said that smoke from Canada's devastating forest fires has reached Europe, which is not unexpected. "Smoke can travel thousands of kilometers in severe fires. According to satellite and model data, smoke from Canada has already reached Estonia, but the amount is so small that it cannot be readily detected," he said.
By the time the smoke from the Canadian fares reaches Europe, it has dissipated and no longer poses a threat. "The main issue is still in the immediate vicinity of the fires, where the thick smoke poses grave health risks," he said. In this respect, Estonia's geographical location is fortunate, as major fires are usually relatively distant, he said.
"Estonia has far less severely hazardous smoke than other countries." As the temperature warms, the weather in southern Europe becomes more suitable to landscape fires, yet even there, dense smoke rarely reaches us," Toll said. By worldwide standards, the air quality in Estonia and northern Europe is excellent.
Toxic smoke from major fires will not be completely eliminated from the air in Estonia. "On occasion, flames west of the Ural Mountains in Russia have a negative impact on Estonian air quality." "As a result of fires in the Ural Mountains to the east, less smoke reaches us," he explained.
A new normal
Many people are forced to live with poor air quality as large-scale landscape fires become increasingly widespread around the world, according to Toll. "At the same time, the fires emit carbon dioxide, which contributes to global warming," he noted, adding that "heat waves in Estonia have already increased due to climate change."
"In Estonia, we haven't really looked in-depth into how climate change will affect us." Climate issues, such as the possibility of forest fires, are growing in Estonia. "We have to become proactive in preparing for the effects of climate change, i.e. adapt to climate change," he said.
Polluted air is becoming an increasing health risk
Margus Viigimaa, a cardiologist and medical scholar, said that environmental factors have risen in the ranks of cardiovascular causes in recent years. "Air pollution damages myocardial cells directly and raises the risk of cardiovascular fatality. These include heart attacks, irregular heartbeats and arterial blockages," the doctor said.
"According to famous German cardiologist Stephan Achenbach, who spoke at the recent European Society of Cardiologists congress, air pollution is now as harmful as smoking," he said. He went on to say that air pollution kills 8.8 million people each year and reduces life expectancy by 2.9 years on average. "These are very high numbers."
However, forest fires are not the only source of air pollution; cardiologists also believe that industry and cars play a role. According to Viigimaa, even in climate-conscious Europe, the air problem is so significant that the European Society of Cardiology recommends heart health screening in industrial and urban regions.
"Following the example of some Asian countries, such as China, people in areas with polluted air could wear masks and have air purifiers in their homes," Viigimaa proposed.
Despite the fact that Estonia's air is cleaner than the European average, "old houses frequently have stove heating and inadequate ventilation," he said.
He claims that the widespread use of stoves has an especially harmful influence on air quality in Estonia during the winter, when numerous roaring chimneys can be seen in older, wooden houses throughout the city. "We need more modern living space with better ventilation conditions," Viigimaa said.
Viigimaa recommends avoiding driving on major highways, particularly in windy conditions. In the spring, when the snow has melted but vehicles are still driving on studded tires, a great deal of rubber particles, road debris, and anti-slip grit are released into the air, he added.
Risk of forest fires also increasing in Estonia
Forest fires are also on the rise in Estonia, according to Marek Metslaid, professor of forest ecology at the Estonian University of Life Sciences. "When we look at climate change, we see rising temperatures and more frequent droughts that cause fires. This, in turn, has an impact on the dynamics of soil carbon, nitrogen, soil fungi and vegetation," Metslaid explained to ERR.
"In and of themselves, higher air temperatures increase the risk of a fire." Higher air temperatures can also increase the amount of water vapor in the air. This causes more evaporation, making the combustion material drier and easier to ignite," Kalev Jõgiste, senior researcher in forest ecology at the Estonian University of Life Sciences.
Metslaid and Jõgiste research forest fires and their aftermath. Metslaid and his colleagues are investigating in greater detail how forest fires impact the vegetation, soil and soil quality of the Estonian forests.
According to the researchers, the structure and properties of the forest ecosystem's biomass determine whether and how various materials flame up in the forest. "As in other regions of the world, our forests are composed of large quantities of combustible living and nonliving organic matter," they said.
Living organic matter contains more water and is less flammable because a portion of the energy is used to evaporate the water. Long droughts are marked by scant precipitation and sustained high air temperatures, which makes any forest flammable. "If the drought persists for an extended period of time, our forests will be extremely flammable," Jõgiste said.
Coniferous forests, according to forest specialists, are the most combustible. "Coniferous woods have less undergrowth and increased ground and forest floor evaporation. During hot weather, decaying organic debris on the forest floor becomes a fire hazard."
According to forest scientists, dried needles are highly flammable, particularly in pine forests. "Pine needles are big and form a fluffy, airy mat when they decompose. If there is an external source of ignition, the material is easily ignited and the fire quickly spreads. Under the spruce trees, the needle thicket is more concentrated and less combustible.
A ground fire or smoldering vegetation, on the other hand, can be converted into the burning of living trees. "Spruce tree branches extend to the ground, allowing fire to spread to the tops." Pines have a higher live crown than spruces, which reduces the risk of fire in pine stands. "The burning of living twigs releases flammable gaseous compounds, so the fire spreads quickly," Jõgiste adds.
Forest scientists stressed the importance of fire in the forest ecosystem. Any forest can catch fire. "Many fundamental principles have been lost in modern society. It has been forgotten, e.g., that the more combustible material accumulates, the greater the risk of forest fires."
Good forest management reduces fire risk
According to Metslaid and Jõgiste, woods containing a lot of combustible material, like decaying wood, undergrowth and vegetation, are more likely to catch fire. "We have to also take into account the cumulative effects of concurrent occurrences, so during dry periods, severe storm damage and worm damage generate a significant amount of combustible debris," they said.
"As a consequence of global warming, even in regions where forest fires are not typically a problem, the risk of forest fires is increasing. When a stable fire starts, it spreads rapidly. You cannot escape from it. "The situation is especially dire when there is nowhere to flee and fire is all around," Jõgiste stated.
Forest scientists believe that prudent forest management, which entails routine maintenance and renewal, reduces the likelihood of forest fires. In areas where forest fires occur regularly, the community has adapted to the danger they pose. The risk of forest fires can be reduced by removing flammable materials. "Developing stands with a more fire-resistant composition and structure of tree species has contributed to reducing the risk of forest fires," the researchers said.
"The higher percentage of mixed forests will make our forests more resistant to pests, diseases and other disturbances, such as forest fires," Metslaid added.
"Decisions made today can ensure the health and sanitation of forests in the future." Forests that have been properly maintained and regenerated are more resistant to a range of disturbances, such as forest fires. One strategy for reducing the risk of forest fires is to plant low-fire-danger mixed stands. Metslaid came to the conclusion that woodlands should not be overly concentrated.
Editor: Kristina Kersa