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Rising ocean temperatures in the Pacific are changing the West Coast’s precipitation patterns

Rising ocean temperatures in the Pacific are at the core of the West Coast’s precipitation patterns, driving winter storms, and could wind up causing the climate of the Pacific Northwest and Southwest to switch, a new study suggests.

Researchers from Cooperative Institute for Research in Environmental Sciences (CIRES), the National Oceanic and Atmospheric Administration and the University of Colorado have determined that ocean temperatures and not the planet’s ice sheets, are ‘directly responsible’ for changing the North Pacific’s atmosphere and the West Coast’s precipitation patterns.

This happened during the Last Glacial Maximum, which occurred between 31,000 and 16,000 years ago and is currently happening now.

The changes are noteworthy given the fact it does not require an ice sheet to occur, the researchers said.

Rising ocean temperatures in the Pacific are causing changes to the West Coast’s precipitation patterns

Similar to what happened during the Last Glacial Maximum, the climates of the Pacific Northwest and Southwest could switch

Similar to what happened during the Last Glacial Maximum, the climates of the Pacific Northwest and Southwest could switch

Scientists originally thought that during the Last Glacial Maximum, roughly 20,000 years ago, large ice sheets hovered over North America and these ice sheets caused the dramatic shift in the atmosphere’s circulation.  

Given that Pacific Ocean temperatures and West Coast precipitation patterns are linked, it could mean there could be a ‘dramatic change’ in the West Coast climate in a relatively short period of time.

‘It is distinctly plausible that we could get an ocean temperature pattern in the North Pacific that looks very much like what we saw during the Last Glacial Maximum,’ the study’s lead author, Dillon Amaya, added.

‘This could lead to dramatic changes in West Coast hydroclimate over a relatively short period of time, like decades.’   

The changes do not require the presence of an ice sheet, as scientists previously thought

The changes do not require the presence of an ice sheet, as scientists previously thought

During the Last Glacial Maximum, large ice sheets hovered over North America that caused the dramatic shift in the atmosphere's circulation

During the Last Glacial Maximum, large ice sheets hovered over North America that caused the dramatic shift in the atmosphere’s circulation

Amaya noted that although there is no change a nearly 2 mile tall (3 kilometers) ice sheet will appear ‘suddenly’ over North America, the modern climate ‘can produce similar changes in North Pacific ocean temperatures that could temporarily swap the climates of the Southwest and the Pacific Northwest.’ 

Scientists originally thought that during the Last Glacial Maximum, roughly 20,000 years ago, large ice sheets hovered over North America and these ice sheets caused the dramatic shift in the atmosphere’s circulation.

‘This study highlights the need for a holistic view of the climate system, especially when modeling its past and future behavior,’ said coauthor and CIRES Fellow Kris Karnauskas in a statement. 

‘Without accounting for the interaction between the atmosphere and ocean, you can end up with the right answer for the wrong reason, which is of course risky when you try to extrapolate that information to future concerns like freshwater availability.’

The study shows that the ocean temperatures of the Last Glacial Maximum were not unique to that time period. 

The researchers note that during this period, the Southwestern U.S. was full of precipitation and the Pacific Northwest was dry, drastically different from how these regions are today.

It was believed the Northern Hemisphere ice sheets acted as a barrier and pushed the North Pacific jet stream and storms south, but after researching deeper, they found that was not the case.

‘There’s also the thermodynamic effect of having a really bright ice sheet that reflects a lot of sunlight,’ Amaya explained. ‘That creates cooling that also adjusts atmospheric circulation.’

The study shows that the ocean temperatures of the Last Glacial Maximum were not unique to that time period

The study shows that the ocean temperatures of the Last Glacial Maximum were not unique to that time period

The researchers used a climate model that also simulated the ocean’s response to ice sheets and how it interacts with the atmosphere to come up with their findings. 

‘This study highlights the need for a holistic view of the climate system, especially when modeling its past and future behavior,’ said coauthor and CIRES Fellow Kris Karnauskas explained. 

‘Without accounting for the interaction between the atmosphere and ocean, you can end up with the right answer for the wrong reason, which is of course risky when you try to extrapolate that information to future concerns like freshwater availability.’

‘It is distinctly plausible that we could get an ocean temperature pattern in the North Pacific that looks very much like what we saw during the Last Glacial Maximum,’ Amaya said. 

‘This could lead to dramatic changes in West Coast hydroclimate over a relatively short period of time, like decades.

Though the ice sheets do not play the preeminent role in pushing the storms south, they do play a role, albeit one that could be considered behind the scenes. 

The study was recently published in the scientific journal Earth and Planetary Science Letters.

SEA LEVELS COULD RISE BY UP TO 4 FEET BY THE YEAR 2300

Global sea levels could rise as much as 1.2 metres (4 feet) by 2300 even if we meet the 2015 Paris climate goals, scientists have warned.

The long-term change will be driven by a thaw of ice from Greenland to Antarctica that is set to re-draw global coastlines.

Sea level rise threatens cities from Shanghai to London, to low-lying swathes of Florida or Bangladesh, and to entire nations such as the Maldives.

It is vital that we curb emissions as soon as possible to avoid an even greater rise, a German-led team of researchers said in a new report.

By 2300, the report projected that sea levels would gain by 0.7-1.2 metres, even if almost 200 nations fully meet goals under the 2015 Paris Agreement.

Targets set by the accords include cutting greenhouse gas emissions to net zero in the second half of this century.

Ocean levels will rise inexorably because heat-trapping industrial gases already emitted will linger in the atmosphere, melting more ice, it said.

In addition, water naturally expands as it warms above four degrees Celsius (39.2°F).

Every five years of delay beyond 2020 in peaking global emissions would mean an extra 20 centimetres (8 inches) of sea level rise by 2300.

‘Sea level is often communicated as a really slow process that you can’t do much about … but the next 30 years really matter,’ said lead author Dr Matthias Mengel, of the Potsdam Institute for Climate Impact Research, in Potsdam, Germany.

None of the nearly 200 governments to sign the Paris Accords are on track to meet its pledges.

Read more at DailyMail.co.uk