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Downright apocalyptic images coming out of Australia right now.
现在澳大利亚出现了世界末日般的画面。
There are now six fires burning at emergency levels.
目前澳大利亚有六处火灾处于紧急状态。
The smoke is so intense and so thick it can be seen from space.
从太空就能够看到这里滚滚的浓烟。
2,000 homes have been destroyed. Six million hectares of land charred.
2000所房屋被毁。600万公顷土地被烧焦。
Staggering toll on the nation's wildlife. This is just heartbreaking.
该国野生动物伤亡数量惊人。这真是令人心碎。
These record-breaking bushfires in Australia have been kicked off by things like lightning strikes, a few cases of arson and winds.
此次澳大利亚的史上森林大火是由雷击、及其故意纵火和大风等引起的。
But one of the biggest reasons they've become so extreme, is the same reason East Africa is flooding.
但灾情变得如此极端的最大原因之一，和东非洪水泛滥的原因是一样的。
Bushfires in Australia are a natural part of the country's ecosystem.
澳大利亚的森林火灾是该国生态系统的天然组成部分。
Their "fire season" varies across regions.
该国的“火灾季节”因地区而异。
Even New South Wales, the most populous state, is used to blazes breaking out.
即使是人口最多的新南威尔士州，也常常发生火灾。
In 1974, fires burned 3.5 million hectares, and in 2003, another 2 million hectares were lost to fire.
1974年，大火烧毁了350万公顷土地；2003年，又有200万公顷土地被大火烧毁。
But the fires that started in 2019 are even worse: 4.9 million hectares in New South Wales
但2019年的火灾灾情更加糟糕：新南威尔士州已经有490万公顷的土地被烧毁，
have burned already — and it's only going to grow. So why is this fire season so awful?
且该数字只会继续增长。所以这次的火灾季节为什么如此糟糕呢？
For starters, as the world is getting warmer from climate change, so is Australia.
首先，全球气候变暖，澳大利亚也一样。
2019 was its hottest year on record, with parts of the country reaching 45 degrees Celsius in December.
2019年是该国有记录以来最炎热的一年，12月，该国部分地区气温高达45摄氏度。
2019 was also it's driest — the places here in gray have seen historic droughts.
2019年是最干的一年——灰色区域内的地方出现了历史性的干旱。
Together, that provides the perfect conditions for bushfires to start and spread quickly.
所有这些都为森林火灾的开始和迅速蔓延提供了完美的条件。
Throughout the year, other large-scale climate drivers affect Australia's weather, and its likeliness to burn.
全年中，其他大规模的气候驱动因素影响着澳大利亚的天气和引起火灾的可能性。
But one of the most influential is the Indian Ocean Dipole, or the IOD.
但其中最具影响力的是印度洋偶极子，简称IOD。
The IOD is a big temperature gradient that affects the surface water in the Indian Ocean,
IOD是一个很大的温度梯度，它影响着从非洲边缘
from the edge of Africa to the edge of Australia.
到澳大利亚边缘的印度洋地表水。
Meteorologists have been measuring these temperature shifts for decades in three phases: Positive, neutral and negative.
几十年来，气象学家一直将这些温度变化分为三个阶段进行测量：暖性（正）、中性和冷性（负）。
When the IOD is neutral, the surface water in the Indian Ocean is evenly warm.
当IOD是中性时，印度洋地表水的温度是均匀温暖的。
A negative phase is when winds come in from the east and shift the warm water toward Australia.
中性阶段是指当风从东部吹来，并把温暖的海水吹向澳大利亚时。
Warmer water means more evaporation which means more rain.
更加温暖的水温意味着更多的蒸发，也就意味着更多的降雨。
So Australia gets more rain than usual, sometimes even floods.
所以澳大利亚此时的降水比平时多，有时甚至会导致洪灾。
But the colder water near East Africa means they get less rain and even drought.
但东非附近较冷的水温意味着雨水更少，甚至会出现干旱。
A positive phase is what's happening now. It's when the winds come from the west and shift the warm water towards Africa.
暖性阶段就是此时正在发生的。它指的是当自西部的风吹来，并把温暖的海水吹向非洲的时候。
Which causes flooding there, and drought in Australia. The entire process of shifting water temperatures is natural.
这会导致非洲发洪水，澳大利亚出现干旱。改变水温的整个过程是自然的。
But 2019's was extreme. The positive IOD was one of the strongest on record,
但是2019年的就很极端。2019年的暖性IOD是有史以来最强的之一，
with the water temperature difference between Africa and Australia being unusually high.
其非洲和澳大利亚之间的水温区别异常之高。
Hence, extreme weather in Australia, but also in Africa. The worst flooding in two decades.
因此，澳大利亚和非洲都出现了极端气候。20年来最严重的洪灾。
More than three times their annual rainfall in only four days.
仅四天的降雨量就超过了全年降雨量的三倍。
Scientists believe it's linked to record temperatures in the Indian Ocean.
科学家认为这创下了印度洋的温度记录。
The good news is the IOD is already shifting to neutral
好消息是IOD已经向中性转变
which should bring some much needed relief to Australia and Africa in early 2020.
这应该能在2020年初为澳大利亚和非洲带来一些必要的缓解。
But as the planet continues to warm, some scientists are concerned about
但是随着地球持续变暖，一些科学家担心
how that might affect weather phenomenons like the IOD.
这会给像IOD这样的天气现象带来怎样的影响。
One study predicts positive IODs, like what we're seeing now,
一项研究预测，随着全球气温上升和印度洋变暖，
could happen more frequently as global temperatures rise and warm the Indian Ocean.
像现在这样的暖性IOD可能会更加频繁地发生。
Combine that with the rising overall temperature of Australia,
再加上澳大利亚整体气温的上升，
and these kinds of devastating fires, fueled by unusually dry vegetation, could become the new normal.
这些由异常干燥的植被所引发的毁灭性的火灾可能成为新常态。
