The Climate System Research Center at the University of Massachusetts Amherst in partnership with the University of Québec found that the last decade shows the warmest sea-surface temperature for nearly 3,000 years.
Led by Postdoctoral Associate François Lapointe, Raymond Bradley, Director of the Climate System Research Center of UMass Amherst, and Pierre Francus, Professor of Institute National de la Recherche Scientifique (National Institute of Scientific Research) of UOQ, they analyzed “perfectly preserved” yearly layers of sediment that accumulated in a lake on northern Ellesmere Island, Nunavut.
Nunavut is the largest and most northerly territory of Canada.
The research team found that the coldest temperatures were between about 1400-1600 A.D. and the warmest interval occurred during just the past decade.
The sediment contains titanium left over from centuries of rock weathering. By measuring the titanium concentration from the different layers, scientists have been able to estimate the relative temperature and atmospheric pressure over time.
“Using these strong links, it was possible to reconstruct how Atlantic sea surface temperatures have varied over the past 2,900 years,” said Lapointe. “Making it the longest record that is currently available.”
When temperatures are cool over the North Atlantic, a relatively low atmospheric pressure pattern is found over much of the Canadian High Arctic and Greenland. This is associated with slower snowmelt in that region and higher titanium levels in the sediments. The opposite is true when the ocean is warmer, atmospheric pressure is higher, snowmelt is rapid and the concentration of titanium decreases.
“It has been common in recent summers for atmospheric high-pressure systems, clear-sky conditions, to prevail over the region. Maximum temperatures often reached 68 degrees Fahrenheit, for many successive days or even weeks, as in 2019,” Lapointe said. “This has had irreversible impacts on snow cover, glaciers and ice caps and permafrost.”
Permafrost is any ground that remains completely frozen for at least two years straight. These permanently frozen grounds are most common in regions with high mountains and Earth’s higher latitudes, near the North and South Poles.
The findings of the study show similarities with European temperatures over the past 2,000 years, according to Lapointe and his team. Fluctuations in sea surface temperatures, known as the Atlantic Multidecadal Oscillation are linked to other major climatic upheavals such as droughts in North America and the severity of hurricanes.
In April, the department of Atmospheric Science researchers released data that predicted the east-coast should also prepare for a hurricane season that will be feature more powerful storms than usual.
This year has seen 25 storms, second only to 2005′s 28 storms. Ten of those storms made a U.S. landfall, shattering a record that had stood for 104 years.
Climate warming in the Arctic is now twice or three times faster than the rest of the planet because of greenhouse gas emissions from burning fossil fuels, warming can be amplified or dampened by natural climate variability, such as changes in the surface temperature of the North Atlantic, which appear to vary over cycles of about 60 to 80 years, according to a statement from UMass.
President Donald Trump’s rollback of the previous administrations' climate regulations will cause the United States to pump an extra 1.8 billion tons of greenhouse gases into the atmosphere between now and 2035, at a time when scientists say the world needs to slash its carbon pollution dramatically to avoid catastrophe, according to the climate research firm Rhodium Group.
“In 2017, Trump signed an executive order directing the former Environmental Protection Agency director Scott Pruitt to repeal and replace the Clean Power Plan which aimed to cut greenhouse gas emissions from power plants,” the Rhodium Group website states.
The same year Trump also scaled back the federal fuel economy and emission standards for new passenger vehicles.
“The surface waters of the Atlantic have been consistently warm since about 1995. We don’t know if conditions will shift towards a cooler phase any time soon, which would give some relief for the accelerated Arctic warming,” said Bradley. “But if the Atlantic warming continues, atmospheric conditions favoring more severe melting of Canadian Arctic ice caps and the Greenland ice sheet can be expected in the coming decades.”
The Greenland Ice Sheet is a vast body of ice covering over half a million square miles, roughly 79% of the surface of Greenland. It is the second-largest ice body in the world, after the Antarctic ice sheet and saw more than 500 billion tons of mass lost in 2019.
This record-breaking loss is associated with unprecedented, persistent high-pressure atmospheric conditions, according to researchers.
Lapointe warns that the conditions are not properly captured by global climate models and that the models underestimate the potential impact of future warming in our Arctic regions.
“Our unique data set constitutes the first reconstruction of Atlantic sea surface temperatures spanning the last 3,000 years and this will allow climatologists to better understand the mechanisms behind long-term changes in the behavior of the Atlantic Ocean,” Francus said.