Wildfires around the world: The photos that explain the flames

Wildfires have been sweeping through coastal towns east of the Greek capital, Athens. Dozens of people – including families with children – have died as they tried to escape the flames.

But fires are also raging in Sweden, as far north as the Arctic Circle, and have caused huge damage in countries including Portugal, the UK and the US in recent months.

So what is happening to cause these infernos and how can we tackle them?

Flames take hold

Fires can occur naturally in woodland or brush, ignited by heat from the sun or a lightning strike.

However, the vast majority of wildfires – as many as 90% worldwide – are started by humans, according to experts.

The cause could be barbecue charcoal, a discarded cigarette or even arson. As long as there is fuel and oxygen available, the flames can take hold easily.

Greece had an unusually dry winter and spring this year, leaving grass and scrubland particularly flammable, says Thomas Smith, assistant professor in environmental geography at the London School of Economics and Political Science (LSE).

As well as a lack of rainfall, wind also determines how devastating the fire will be, depending on its strength and direction.

“Burning embers can travel quite far and start new fires that could spread for kilometres if they are big enough,” says Smith.

Surface fires – burning on a forest floor, for instance – tend to spread slowly and can be more easily controlled.

In fact some surface fires can be good, says Cathelijne Stoof, a wild land fire expert based in the Netherlands. “It helps plants regenerate,” she adds.

“The problem is when the flames can climb up low level branches and get to the tops of the trees. That’s when you can’t stop it.”