时间:2024-09-20 10:52:42 来源:网络整理编辑:探索
Just days before Christmas in 2016, the North Pole was 50 degrees above its usual winter temperature
Just days before Christmas in 2016, the North Pole was 50 degrees above its usual winter temperature. The top of the world was just above freezing.
Unusually warm air had smothered the Arctic throughout that year, and now a recently published report, led by government scientists at the National Oceanic and Atmospheric Administration (NOAA), found that it's nearly impossible to explain the intensity of this warmth simply by normal fluctuations in weather.
A heating event like this isn't natural, they argue -- it's largely human-induced, specifically by the greenhouse gases emitted by human industry and trapped in the atmosphere.
SEE ALSO:Your international vacation is a whole lot worse for the planet than we thoughtScientists have long predicted that the Arctic would show extreme, amplified consequences of these emissions, particularly as sea ice melts and plummets in size.
“It’s been said the Arctic is the canary in the coal mine,” NOAA meteorologist and study co-author Martin Hoerling said in a statement. “The canary in the coal mine really chirped loudly in 2016. This is where the signal is clearly emerging beyond the noise, and it affirms predictions of how climate change will unfold on Earth.”
The research team was able to show that back in the late 1800s, when greenhouse gas emissions were considerably lower than they are today, such abnormal Arctic heat waves would have a "near zero" chance of occurring, Lantao Sun, an NOAA atmospheric scientist and lead author of the study, said in an email.
NOAA graphics showing that the Arctic is warming twice as quickly as the global average.Credit: NOAATo show this, the research team plugged actual measurements, including greenhouse gases, sea-surface temperatures, and sea ice concentrations, into a widely-used computer model to see if it accurately reproduced the 2016 warming event in the Arctic -- which it did.
Then, they turned greenhouse gas emissions and temperatures down to their late-1800s levels -- back when the Earth was cooler and greenhouse gas emissions were considerably less.
After running this 19th-century experiment 30 times, they found that without those climate change indicators, "the Arctic is considerably colder than what we observed recently and there is near-zero probability for the Arctic surface temperature to be as warm as in 2016," said Sun.
Similar warming events in the Arctic have now occurred every winter for the past three years, "which is what we expect under warming conditions," Walt Meier, a senior research scientist at the National Snow and Ice Data Center, said in an interview.
"Three years in a row is something you take notice of -- that's something unusual," Meier, who had no involvement in the study, said.
But, cautions Meier, saying that a particular warming event is a human-induced climate effect, rather than inherently fickle weather, is tricky to do with the limited data we have. Reliable temperature monitoring in the hard-to-reach Arctic doesn't go back that far, only to the early 1980s.
"With warming trends we're just kind of rolling the dice -- we can still get odd things that can happen," he said.
Older sea ice, which is thicker and more resistant to warming, has declined dramatically in the Arctic.Credit: NOAA"It's like rolling double sixes two times in a row -- it does happen," said Meier. "But if it starts happening four times in row or eight out of 10 times you’re going to become suspicious."
"And we’re getting to that."
Even so, less sea ice -- which is at its lowest point in the last 1,500 years in the Arctic -- means more heat waves to come.
Sea ice acts as a formidable "bulwark" to storms carrying heat and moisture into the Arctic, often breaking the storms apart, said Meier.
And with less ice, comes less protection.
"I think we should expect to see more frequent heat waves in the Arctic, particularly in the winter, due to less sea ice allowing the storms to more easily track into the Arctic," said Meier.
Sun said we should "absolutely" expect to see more warming in the Arctic, noting that the study found that 60 to 70 percent of the 2016 Arctic warming can be attributed to the loss of sea ice. The rest was caused by natural intrusions of warm air into the Arctic, including contributions from El Niño.
Arctic weather in 2016 may have often been abnormal or anomalous, but to many scientists, it's becoming all too common.
"It is not only astonishing to see how large the warm anomaly in the Arctic is from day to day compared with other regions on Earth," Jason Briner, who researches global climate change at the University of Buffalo and had no involvement in the research, said in an email.
"It is also remarkable how persistent the extreme warm weather is in the Arctic. In fact, the warm weather events are so persistent that we can no longer call it weather, but we have no choice but to call it a new climate state."
J.K. Rowling makes 'Harry Potter' joke about Olympics event2024-09-20 10:50
國米前瞻 :藍黑軍再遇苦主 戰殘陣礦工欲提前出線2024-09-20 10:32
梅西亞斯 :米蘭還活著 這是職業生涯最美妙的夜晚2024-09-20 10:28
原諒他了?格拉利什女友曬無名指戒指 疑似已訂婚2024-09-20 09:56
The five guys who climbed Australia's highest mountain, in swimwear2024-09-20 09:46
國米前瞻:藍黑軍再遇苦主 戰殘陣礦工欲提前出線2024-09-20 09:20
媒體人:國足單場贏球獎金600萬 主教練多少錢很好預估 2024-09-20 08:46
尤文遭遇17年來最慘痛失利 跌至第二淘汰賽蒙陰影2024-09-20 08:25
There's a big piece of fake chicken stuck to this phone case2024-09-20 08:19
李佳悅發文鼓勵邱芳芳 :上海女足是你最堅強的後盾2024-09-20 08:13
There's a big piece of fake chicken stuck to this phone case2024-09-20 10:47
尤文冬窗5000萬歐急購紫百合神鋒 遭索價7000萬2024-09-20 10:44
梅西亞斯:米蘭還活著 這是職業生涯最美妙的夜晚2024-09-20 10:14
足協力推留洋武磊示範效應明顯 張玉寧鼓勵朱辰傑出去看看2024-09-20 10:12
Olympics official on Rio's green diving pool: 'Chemistry is not an exact science'2024-09-20 10:02
本澤馬被判企圖勒索同謀罪 1年緩刑罰款7.5萬歐2024-09-20 09:41
卡納瓦羅:已經準備好在歐洲執教 我在廣州做得非常好2024-09-20 09:29
中超還未開啟主角恐隻剩山東海港兩隊 明年前景恐怕更難2024-09-20 09:27
Old lady swatting at a cat ends up in Photoshop battle2024-09-20 08:33
巴薩有意24場造31球鋒霸 身價2000萬盼分期支付2024-09-20 08:24