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Intense wildfires swept across southern Europe, particularly Greece, Spain, France, Portugal and Italy.
Hundreds of thousands of hectares of forest were destroyed and record peacetime evacuations were ordered.
The fires have drawn attention to pyrocumulonimbus clouds, or fire clouds, generated by the blazes themselves.
The pattern of abrupt swings between very wet and very dry conditions is described as climate whiplash.
Mediterranean summers are structurally dry, which makes the region's vegetation highly fire-prone.
A pyrocumulonimbus is a thunderstorm cloud generated by the heat of a fire rather than by ordinary solar heating. A large blaze releases an enormous column of hot air, smoke and water vapour, and if that column rises high enough the moisture condenses and a full convective storm cloud forms above the fire. These clouds are dangerous in a specific way: they produce erratic, gusting winds that drive the fire in unpredictable directions, and they generate lightning that can start entirely new fires many kilometres away. They also inject smoke into the stratosphere, where it can circulate for months. In effect the fire creates its own weather and then feeds on it.
Simple Analogy: It is a fire building its own storm overhead — and that storm then throws sparks somewhere else.
Climate whiplash describes rapid swings between opposite extremes, typically a very wet period followed by an intense dry one. For wildfire the sequence is especially dangerous, because the wet phase drives vigorous growth of grasses and shrubs, and the dry phase then converts all that new growth into fuel. The result is more material to burn and drier conditions to burn it in, arriving in quick succession. This is why a wet spring can be a warning sign for the following summer rather than a reassurance.
Simple Analogy: The wet season stacks the firewood; the dry season lights the match.
Persistent blocking high-pressure systems create the prolonged heat and dryness in which such fires ignite and spread.
A climate of hot dry summers and mild wet winters, which makes its vegetation seasonally fire-prone by nature.
Uttarakhand, Himachal Pradesh and the Western Ghats experience comparable seasonal fire risk driven by the same fuel-and-dryness dynamic.
PyroCb clouds can loft smoke into the stratosphere, where it persists and circulates for months, with radiative effects.
GS Paper 1 > Important Geophysical Phenomena; GS Paper 3 > Environment and Disaster Management
General Awareness > Environment and Current Affairs
A thunderstorm cloud generated by the heat of a large fire, capable of producing erratic winds and lightning.
Rapid alternation between opposite climatic extremes, such as a very wet period followed by an intense dry one.
The quantity of combustible vegetation available to burn in a given area.
A climate type with hot dry summers and mild wet winters, characteristic of southern Europe.