熱浪席捲全球,人體對高溫的耐受臨近極限!大綱

Extreme global temperatures are pushing the human body "close to thermal limits", according to a climate scientist.

一位氣候科學家表示，全球極端氣溫正將人體推向“高溫極限”。

Record-breaking heat has swept through Europe this week with temperatures topping 40°C in a number of countries.

本週，破紀錄的高溫席捲歐洲，一些國家的氣溫超過40攝氏度。

However, in places such as South Asia and the Persian Gulf, people are already enduring temperatures reaching up to 54°C.

然而，在南亞和波斯灣等地，人們忍受的高溫已達54攝氏度。

Despite all the body's thermal efficiencies, these areas could soon be uninhabitable, according to Loughborough University climate scientist Dr Tom Matthews in The Conversation.

拉夫堡大學氣候科學家湯姆·馬修斯博士在The Conversation網站上說，儘管人體的熱效率很高，但這些區域可能很快就不宜居住了。

When air temperature exceeds 35°C, the body relies on sweating to keep core temperatures at a safe level. However, when the "wet bulb" temperature – which reflects the ability of moisture to evaporate – reaches 35°C, this system no longer works.

當氣溫超過35攝氏度時，身體依靠流汗來將核心溫度保持在安全水平。然而，當反映水分蒸發能力的“溼球溫度”達到35攝氏度時，該機能就不再起作用了。

"The wet bulb temperature includes the cooling effect of water evaporating from the thermometer, and so is normally much lower than the normal ("dry bulb") temperature reported in weather forecasts," Dr Matthews wrote.

馬修斯博士寫道：“溼球溫度包括溫度計的水分蒸發冷卻效果，因此通常比天氣預報中的正常（幹球）溫度低得多。”

"Once this wet bulb temperature threshold is crossed, the air is so full of water vapour that sweat no longer evaporates," he said.

他說：“一旦溼球溫度超過閾值，空氣中就充滿了水蒸氣，汗水就不再蒸發了。”

This means the human body cannot cool itself enough to survive more than a few hours.

這意味着人體不能自我降溫，這種情況持續幾個小時就能危及生命。

"Without the means to dissipate heat, our core temperature rises, irrespective of how much water we drink, how much shade we seek, or how much rest we take," he explained.

他解釋說：“如果沒有散熱的方法，人體的核心溫度就會上升，不管我們喝了多少水，在陰涼地方呆了多久，或者休息了多長時間。”

Some areas – which are among the most densely populated on Earth – could pass this threshold by the end of the century, according to Dr Matthews.

馬修斯博士說，地球上人口最密集的一些地區的溼球溫度可能會在本世紀末突破這一閾值。

With climate change starting to profoundly alter weather systems, rising temperatures could soon make parts of the world uninhabitable.

隨着氣候變化開始深度改變天氣系統，不斷上升的氣溫可能很快使部分地區不宜居住。

If electricity can be maintained, living in chronically heat-stressed conditions may be possible but a power outage could be catastrophic.

如果能維持電力供應，長期生活在高熱狀況下是可能的，但停電可能造成災難性後果。

In a recent paper published in Nature Climate Change, Dr Matthews and his team looked at the probability of a "grey swan" event in the case of extreme heat coinciding with massive blackouts.

在最近發表在《自然氣候變化》雜誌上的一篇文章中，馬修斯博士和他的團隊研究了極端高溫和大範圍停電同時發生的“灰天鵝”事件的可能性。

Mega blackouts sometimes follow powerful tropical cyclones. Researchers found that dangerously hot temperatures during a period with no electricity could have catastrophic consequences.

強熱帶氣旋過後，有時會出現大範圍停電。研究人員發現，在停電時，危險的高溫會帶來災難性的後果。

"We looked at tropical cyclones, which have already caused the biggest blackouts on Earth, with the months-long power failure in Puerto Rico after Hurricane Maria among the most serious," Dr Matthews wrote.

馬修斯博士寫道：“我們研究了熱帶氣旋，它們已經造成了地球上範圍最大的停電，其中，颶風瑪麗亞過後波多黎各持續數月的停電屬於最爲嚴重之列。”

"We found that as the climate warms, it becomes ever more likely that these powerful cyclones would be followed by dangerous heat, and that such compound hazards would be expected every year if global warming reaches 4°C.

“我們發現，隨着氣候變暖，這些強大的氣旋之後更有可能出現危險的高溫，如果全球升溫達到4攝氏度，預計每年都會出現這兩種相伴而來的危險。”

"During the emergency response to a tropical cyclone, keeping people cool would have to be as much a priority as providing clean drinking water."

“在應對熱帶氣旋的緊急應對措施中，讓人們保持涼爽應該與提供清潔飲用水一樣成爲當務之急。”

Heat-stressed countries are likely to see the largest absolute increases in humid-heat and they are often the least well-prepared to deal with the hazard. This could drive mass migration, which would make heat a worldwide issue – even for countries that are not experiencing scorching temperatures.

高溫國家很可能出現最嚴重的溼熱絕對值增加，而這些國家應對這種危險往往準備最不充分。這可能會導致大規模的人口遷移，並將使高溫成爲全球性問題，即使對那些沒有經歷高溫的國家也是如此。

Dr Matthews wrote: "The challenges ahead are stark. Adaptation has its limits. We must therefore maintain our global perspective on heat and pursue a global response, slashing greenhouse gas emissions to keep to the Paris warming limits.

馬修斯博士寫道：“未來的挑戰是嚴峻的。適應有其侷限性。因此，我們必須保持對高溫的全球視角，並採取全球應對措施，削減溫室氣體排放，遵守《巴黎協定》的全球變暖上限。”

"In this way, we have the greatest chance of averting deadly heat – home and abroad."

“這樣，我們纔會有最大可能在全球範圍內避免致命的高溫。”