紐時賞析／海洋高溫屢破紀錄 學者指原因「不只是氣候變遷」

Ocean Heat Has Shattered Records for More Than a Year. What’s Happening?

海洋高溫屢破紀錄 原因不僅是氣候變遷

The ocean has now broken temperature records every day for more than a year. And so far, 2024 has continued 2023’s trend of beating previous records by wide margins. In fact, the whole planet has been hot for months, according to many different data sets.

超過一年以來，海洋每天都在打破海溫紀錄。到目前為止，2024年延續了2023年趨勢，持續大幅度打破先前創下的紀錄。事實上，許多不同資料集指出，整個地球已處於炎熱狀態數月。

“There’s no ambiguity about the data,” said Gavin Schmidt, a climatologist and the director of the NASA Goddard Institute for Space Studies. “So really, it’s a question of attribution.”

美國太空總署哥達德太空研究所所長、氣候學家施密特表示：「這些數據沒有模稜兩可之處。所以說實話，這是一個歸因的問題。」

Understanding what specific physical processes are behind these temperature records will help scientists improve their climate models and better predict temperatures in the future.

理解這些溫度記錄背後的特定物理變化過程，將協助科學家改善他們的氣候模型，並在未來更能預測氣溫。

Last month, the average global sea surface temperature reached a new monthly high of 21.07 degrees Celsius,  according to the Copernicus Climate Change Service, a research institution funded by the European Union.

歐盟資助的研究機構「哥白尼氣候變化服務」指上月全球海面平均溫度達到攝氏21.07度的每月溫度新高。

“March 2024 continues the sequence of climate records toppling for both air temperature and ocean surface temperatures,” Samantha Burgess, deputy director of Copernicus, said in a statement.

哥白尼氣候變化服務副主任珊曼莎．勃吉斯在一份聲明中表示：「2024年3月，氣溫和海面溫度持續刷新一系列氣候紀錄。」

The tropical Atlantic is abnormally warm, helping set the stage for a busy hurricane season, according to an early forecast by scientists at Colorado State University. Higher ocean temperatures provide more energy to fuel stronger storms.

美國科羅拉多州立大學科學家一份早期預測指出，熱帶大西洋異常溫暖，為繁忙的颶風季節鋪路。較高海溫會提供更多能量，助長更強的風暴發展。

Global temperatures are rising long-term because the burning of fossil fuels adds greenhouse gases, which warm the planet, to the atmosphere. So far, climate change has raised the global average temperature by about 1.2 degrees Celsius above the preindustrial average temperature. And because it takes more energy to heat up water than air, the oceans have absorbed the vast majority of the planet’s warming from greenhouse gases.

由於燃燒化石燃料增加大氣中導致地球暖化的溫室氣體，全球氣溫長期以來一直上升。目前為止，氣候變遷已使全球平均氣溫較工業化前均溫升高攝氏1.2度。再加上加熱水比加熱空氣需要更多能量，海洋已吸收大部分溫室氣體產生的暖化。

But the “massive, massive records” set over the past year are beyond what scientists would expect to see even considering climate change, Schmidt said.

但施密特說，即使是考慮到氣候變遷，過去一整年創下的「大批、大批紀錄」也超出科學家預期。

What’s different now, compared with this time last year, is that the planet is dealing with the effects of an El Niño event that began in July. El Niño events are natural climate patterns associated with elevated temperatures.

與去年此時相比，現在不同的是地球正在應對去年7月開始的聖嬰現象影響。聖嬰現象是和氣溫上升有關的自然氣候模式。

“The temperatures that we’re seeing now, the records being broken in February and March, are actually much more in line with what we would expect,” compared with those of last year, Schmidt said. “Let’s see what happens by the summer.”

施密特稱，與去年相比，「現在觀察到的氣溫，即2月和3月打破的紀錄，事實上更符合預期。讓我們看看今年夏季前會發生什麼」。

El Niño is weakening and expected to dissipate soon. What happens to global average temperatures then would help shed light on the temperatures of 2023, he said.

聖嬰現象正在減弱且預計很快就會消散。他說，屆時全球平均氣溫的變化將有助於說明2023年的氣溫。

文／Delger Erdenesanaa　譯／羅方妤

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【張佑生】

本文探討海洋溫度持續破紀錄的原因，不光是氣候變遷。Record當「紀錄」（名詞）的一個解釋是最快速度或最遠距離，特別是體育競賽。創紀錄動詞可用set，平紀錄可用equal或tie，保持紀錄用hold，像the record holder（紀錄保持人）。破紀錄用break或beat，大幅(by wide margins)刷新紀錄，可說smash或shatter a record.

近年討論氣候變遷時常出現的一個字是preindustrial（英式用法為pre-industrial），說的是工業革命時期到來，機器開始大量生產物品之前，中文理解為「工業革命前」：the transition from preindustrial to industrial society.「巴黎氣候協定」將目標訂在「全球平均溫度相較於工業化前水準上升幅度控制在1.5℃」(global warming of 1.5°C above pre-industrial levels)。

Climatologist是氣候學家，meteorologist的研究領域則是偏氣象。每節新聞最後出現的氣象預報員用的是weather forecaster，更專業的頭銜就用meteorologist。