Wildfire is a large, uncontrolled fire that burns wildland vegetation (forests, grasslands, savannas) in rural areas. It can be caused by lightning or human carelessness such as a discarded cigarette.
The frequency, intensity and duration of wildfires are influenced by many factors including climate change, drought and land-use changes. Increasing urbanization in what was previously wildlands is also impacting trends in fire occurrence and severity.
Fire is an essential part of the ecosystem – it removes overgrown undergrowth, clears space for new grasses and shrubs to grow, and provides food and shelter for wildlife. However, if too much fuel accumulates and the fire becomes out of control it can be detrimental to humans, livestock and wildlife.
In a typical fire, the heat from the flames heats up wood or other flammable material until it reaches its “flash point” – the temperature at which the materials begin to release gasses that cause them to ignite. This is known as the “fire triangle”. The moisture content of the surrounding environment is also a factor; if humidity is very high, fire will not start or spread quickly.
When wildfires spread, they can smolder for weeks or months and produce a thick haze of smoke that can affect human health, disrupt air and water supplies, damage crops, and destroy property. In addition, the greenhouse gases released into the atmosphere by burning trees and plants contribute to global warming. For these reasons, many scientists study wildfires – including fire ecologists, fire engineers, and climate scientists.