North America’s winter of 2015 defied the norms. Normally frigid areas of the United States had record warmth, but historic snowfalls buried other parts of the country.
Central Asia, the United Kingdom and other European nations also experienced weird winters in recent years.
Though scientists can’t draw direct links between single weather events and global climate change, they find that widely documented Arctic warming is causing unusual weather in the temperate zones north of the tropics, south of the Arctic.
“What happens in the Arctic isn’t staying in the Arctic,” said satellite scientist Jeff Key from NOAA’s Center for Satellite Applications and Research.
He studies satellite imagery and data on winds, chemistry, temperature and humidity. They are all straying from historic norms, and show the Arctic atmosphere is changing, he says.
“What’s important is that this affects midlatitude climate,” Key said. Arctic changes influence the jet stream, giant rivers of air flowing west to east 6 or more kilometers above the Earth.
“As the jet stream weakens, it tends to meander more, and we get more extreme weather in the midlatitudes,” Key said.
Other scientific observations reveal less ice in the Arctic Ocean, which means waters will absorb heat rather than reflect it.
“I think less sea ice is certainly going to change weather patterns, open up [channels] for shipping [and] oil and gas exploration,” Key says. The U.S. Navy foresees similar changes.
“It’s going to be a different world out there.”
The tundra is also warming, and its vegetation is changing. The extent of surface green matter can alter how much sunlight is reflected, so “a change in vegetation can lead to even greater warming, which leads to a greater change in vegetation and so forth,” Key said.
Thawing tundra also means that infrastructure built on what was thought to be perpetually frozen ground can become unstable.
As Key and his scientific colleagues worldwide continue their work to understand the complexities of the northernmost regions, the latest research suggests a changing Arctic will have far-reaching effects.
“It’s going to be a different world out there, I think, in 20, 30, 40 years,” Key says.
As the United States took the chairmanship of the eight-nation Arctic Council in April, Secretary of State John Kerry reminded the world it must protect, respect and nurture the region.