热浪席卷全球,人体对高温的耐受临近极限!

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

一位气候科学家表示，全球极端气温正将人体推向“高温极限”。

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

本周，破纪录的高温席卷欧洲，一些国家的气温超过40摄氏度。

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

然而，在南亚和波斯湾等地，人们忍受的高温已达54摄氏度。

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.

拉夫堡大学气候科学家汤姆·马修斯博士在The Conversation网站上说，尽管人体的热效率很高，但这些区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.

当气温超过35摄氏度时，身体依靠流汗来将核心温度保持在安全水平。然而，当反映水分蒸发能力的“湿球温度”达到35摄氏度时，该机能就不再起作用了。

"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.

马修斯博士写道：“湿球温度包括温度计的水分蒸发冷却效果，因此通常比天气预报中的正常（干球）温度低得多。”

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

他说：“一旦湿球温度超过阈值，空气中就充满了水蒸气，汗水就不再蒸发了。”

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

这意味着人体不能自我降温，这种情况持续几个小时就能危及生命。

"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.

他解释说：“如果没有散热的方法，人体的核心温度就会上升，不管我们喝了多少水，在阴凉地方呆了多久，或者休息了多长时间。”

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.

马修斯博士说，地球上人口最密集的一些地区的湿球温度可能会在本世纪末突破这一阈值。

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

随着气候变化开始深度改变天气系统，不断上升的气温可能很快使部分地区不宜居住。

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

如果能维持电力供应，长期生活在高热状况下是可能的，但停电可能造成灾难性后果。

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.

在最近发表在《自然气候变化》杂志上的一篇文章中，马修斯博士和他的团队研究了极端高温和大范围停电同时发生的“灰天鹅”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.

强热带气旋过后，有时会出现大范围停电。研究人员发现，在停电时，危险的高温会带来灾难性的后果。

"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.

马修斯博士写道：“我们研究了热带气旋，它们已经造成了地球上范围最大的停电，其中，飓风玛丽亚过后波多黎各持续数月的停电属于最为严重之列。”

"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.

“我们发现，随着气候变暖，这些强大的气旋之后更有可能出现危险的高温，如果全球升温达到4摄氏度，预计每年都会出现这两种相伴而来的危险。”

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

“在应对热带气旋的紧急应对措施中，让人们保持凉爽应该与提供清洁饮用水一样成为当务之急。”

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.

高温国家很可能出现最严重的湿热绝对值增加，而这些国家应对这种危险往往准备最不充分。这可能会导致大规模的人口迁移，并将使高温成为全球性问题，即使对那些没有经历高温的国家也是如此。

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.

马修斯博士写道：“未来的挑战是严峻的。适应有其局限性。因此，我们必须保持对高温的全球视角，并采取全球应对措施，削减温室气体排放，遵守《巴黎协定》的全球变暖上限。”

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

“这样，我们才会有最大可能在全球范围内避免致命的高温。”