Published on: June 16, 2023

Canada fires

Canada fires

Why in news? New York City’s air quality was recently among the worst in the world due to smoke drifting from the wildfires in Canada.


  • Areas from the mid-Atlantic through the northeast and upper parts of the Great Lakes registered air quality in ‘unhealthy’ or worse categories.
  • Quebec is Canada’s largest province by area is the most currently active wildfires.

What’s causing the wildfires?

  • Lightning is the main precursor of natural wildfires.
  • Lightning electric currents that flow for more than some tens of milliseconds, called long-continuing currents (LCC), are likely to produce fires.
  • There increased activity over land, implying a higher risk of lightning-ignited wildfires in the future.

How does lightning work?

  • During a storm, water droplets in warmer air and ice crystals that condensed in cooler air coalesce together to form thunderstorm clouds (usually cumulonimbus clouds).
  • Contact between these droplets and crystals produces a static electrical charge in the clouds, negative and positive charges in the clouds build up.
  • Over time, the voltage difference becomes high enough to surmount the resistance presented by the air, leading to a rapid discharge of electric charge resulting lightning flash.
  • It can occur between oppositely charged surfaces within a thunderstorm cloud or between such surfaces in the cloud and on the ground.

Is lightning a climate indicator?

  • Long-term changes in lightning patterns reflect, at least in part, changes wrought by the climate crisis.
  • The World Meteorological Organisation recognises lightning to be an essential climate variable that contributes critically to the way the earth’s climate is characterised.
  • Lightning also produces nitrogen oxides, which react with oxygen in the air to form ozone, which is a strong greenhouse gas.