Wildfire

Wildfires are a common type of disaster in some regions, including Siberia (Russia), California, Washington, Oregon, Texas, Florida, (United States), British Columbia (Canada), and Australia.

[58] They may also spread by jumping or spotting as winds and vertical convection columns carry firebrands (hot wood embers) and other burning materials through the air over roads, rivers, and other barriers that may otherwise act as firebreaks.

[63] Great vertical differences in temperature and humidity encourage pyrocumulus clouds, strong winds, and fire whirls with the force of tornadoes at speeds of more than 80 kilometres per hour (50 mph).

[75] Climate variability including heat waves, droughts, and El Niño, and regional weather patterns, such as high-pressure ridges, can increase the risk and alter the behavior of wildfires dramatically.

[79] High temperatures dry out the fuel loads and make them more flammable, increasing tree mortality and posing significant risks to global forest health.

[98][16] While direct emissions of harmful pollutants can affect first responders and residents, wildfire smoke can also be transported over long distances and impact air quality across local, regional, and global scales.

[99]The health effects of wildfire smoke, such as worsening cardiovascular and respiratory conditions, extend beyond immediate exposure, contributing to nearly 16,000 annual deaths, a number expected to rise to 30,000 by 2050.

[103] Forest fires in Indonesia in 1997 were estimated to have released between 0.81 and 2.57 gigatonnes (0.89 and 2.83 billion short tons) of CO2 into the atmosphere, which is between 13–40% of the annual global carbon dioxide emissions from burning fossil fuels.

The recent wildfires and their massive CO2 emissions mean that it will be important to take them into consideration when implementing measures for reaching greenhouse gas reduction targets accorded with the Paris climate agreement.

[144] Larger, medium-risk areas can be monitored by scanning towers that incorporate fixed cameras and sensors to detect smoke or additional factors such as the infrared signature of carbon dioxide produced by fires.

[145][146][147] The Department of Natural Resources signed a contract with PanoAI for the installation of 360 degree 'rapid detection' cameras around the Pacific northwest, which are mounted on cell towers and are capable of 24/7 monitoring of a 15 mile radius.

[148] Additionally, Sensaio Tech, based in Brazil and Toronto, has released a sensor device that continuously monitors 14 different variables common in forests, ranging from soil temperature to salinity.

In advance of that campaign, the Meraka Institute of the Council for Scientific and Industrial Research in Pretoria, South Africa, an early adopter of the VIIRS 375 m fire product, put it to use during several large wildfires in Kruger.

[174] Wildland fire fighters face several life-threatening hazards including heat stress, fatigue, smoke and dust, as well as the risk of other injuries such as burns, cuts and scrapes, animal bites, and even rhabdomyolysis.

[179] Wildfire debris (ash and sediment) clog rivers and reservoirs increasing the risk for floods and erosion that ultimately slow and/or damage water treatment systems.

However, on the positive side, fire retardant (specifically its nitrogen and phosphorus components) has been shown to have a fertilizing effect on nutrient-deprived soils and thus creates a temporary increase in vegetation.

The vertical lift of a severe thunderstorm or pyrocumulonimbus can be enhanced in the area of a large wildfire, which can propel smoke, soot (black carbon), and other particulate matter as high as the lower stratosphere.

The increased fire frequency in these ordinarily fire-dependent areas has upset natural cycles, damaged native plant communities, and encouraged the growth of non-native weeds.

[42][117] In the Amazon rainforest, drought, logging, cattle ranching practices, and slash-and-burn agriculture damage fire-resistant forests and promote the growth of flammable brush, creating a cycle that encourages more burning.

Researchers estimated that, in worst case scenarios, more than 286 days of constant flushing of a contaminated HDPE service line were needed to reduce benzene below safe drinking water limits.

[234] An observational study of smoke exposure related to the 2007 San Diego wildfires revealed an increase both in healthcare utilization and respiratory diagnoses, especially asthma among the group sampled.

[240] PM triggers a series of biological processes including inflammatory immune response, oxidative stress, which are associated with harmful changes in allergic respiratory diseases.

[255] Looking at the wildfires in Southern California in 2003, investigators have shown an increase in hospital admissions due to asthma symptoms while being exposed to peak concentrations of PM in smoke.

[277] Direct risks to building residents in fire-prone areas can be moderated through design choices such as choosing fire-resistant vegetation, maintaining landscaping to avoid debris accumulation and to create firebreaks, and by selecting fire-retardant roofing materials.

[278] The first evidence of wildfires is fossils of the giant fungi Prototaxites preserved as charcoal, discovered in South Wales and Poland, dating to the Silurian period (about 430 million years ago).

Scottish botanist David Douglas noted the native use of fire for tobacco cultivation, to encourage deer into smaller areas for hunting purposes, and to improve foraging for honey and grasshoppers.

[292] In the post-World War II Baltic region, socio-economic changes led more stringent air quality standards and bans on fires that eliminated traditional burning practices.

[291] In the mid-19th century, explorers from HMS Beagle observed Australian Aborigines using fire for ground clearing, hunting, and regeneration of plant food in a method later named fire-stick farming.

However, a period of increased fire frequency between 1750 and 1870 was suggested by charcoal data from North America and Asia, attributed to human population growth and influences such as land clearing practices.

[308] There are also significant indirect or second-order societal impacts from wildfire, such as demands on utilities to prevent power transmission equipment from becoming ignition sources, and the cancelation or nonrenewal of homeowners insurance for residents living in wildfire-prone areas.