Name: Why Australia's fires are linked to floods in Africa
Uploaded: 2020-01-20T07:30:44.000Z
Duration: 3 min 55 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Downright apocalyptic images coming out of Australia right now.

There are now six fires burning at emergency levels.

Adverbs of degree

The smoke is so intense and so thick, it can be seen from space.

A staggering toll on the nation's wildlife.

These record-breaking bushfires in Australia have been kicked off by things like lightning strikes, a few cases of arson, and winds.

But one of the biggest reasons they've become so extreme is the same reason that East Africa is flooding.

Bushfires in Australia are a natural part of the country's ecosystem.

Their "fire season" varies across regions.

Even New South Wales, the most populous state, is used to blazes breaking out.

In 1974, fires burned 3.5 million hectares, and in 2003, another 2 million hectares were lost to fire.

But the fires that started in 2019 are even worse: 4.9 million hectares in New South Wales have burned already, and it's only going to grow.

For starters, as the world is getting warmer from climate change, so is Australia.

2019 was its hottest year on record, with parts of the country reaching 45 degrees Celsius in December.

The places here in gray have seen historic droughts.

Together, that provides the perfect conditions for bushfires to start and spread quickly.

Throughout the year, other large-scale climate drivers affect Australia's weather, and its likeliness to burn.

But one of the most influential is the Indian Ocean Dipole, or the IOD.

The IOD is a big temperature gradient that affects the surface water in the Indian Ocean from the edge of Africa to the edge of Australia.

Meteorologists have been measuring these temperature shifts for decades in three phases: positive, neutral, and negative.

When the IOD is neutral, the surface water in the Indian Ocean is evenly warm.

A negative phase is when winds come in from the west and shift the warm water toward Australia.

Warmer water means more evaporation, which means more rain.

So, Australia gets more rain than usual, sometimes even floods.

But the colder water near East Africa means they get less rain and even drought.

A positive phase is what's happening now.

It's when the winds come in from the east and shift the warm water towards Africa, which causes flooding there, and drought in Australia.

The entire process of shifting water temperatures is natural.

The positive IOD was one of the strongest on record, with the water temperature difference between Africa and Australia being unusually high.

Hence, extreme weather in Australia, but also in Africa.

More than three times their annual rainfall in only four days.

Scientists believe it's linked to record temperatures in the Indian Ocean.

The good news is the IOD is already shifting to neutral, which should bring some much-needed relief to Australia and Africa in early 2020.

But as the planet continues to warm, some scientists are concerned about how that might affect weather phenomenons like the IOD.

One study predicts positive IODs, like what we're seeing now, could happen more frequently as global temperatures rise and warm the Indian Ocean.

Combine that with the rising overall temperature of Australia, and these kinds of devastating fires, fueled by unusually dry vegetation, could become the new normal.