The deep ocean is warming slowly -- but dramatic changes are ahead

May 25, 2020

The world's deep oceans are warming at a slower rate than the surface, but it's still not good news for deep-sea creatures according to an international study.

The research, led by University of Queensland PhD student Isaac Brito-Morales, looked at how ocean life was responding to climate change.

"We used a metric known as climate velocity which defines the likely speed and direction a species shifts as the ocean warms," Mr Brito-Morales said.

"We calculated the climate velocity throughout the ocean for the past 50 years and then for the rest of this century using data from 11 climate models.

"This allowed us to compare climate velocity in four ocean depth zones - assessing in which zones biodiversity could shift their distribution the most in response to climate change."

The researchers found climate velocity is currently twice as fast at the surface because of greater surface warming, and as a result deeper-living species are less likely to be at risk from climate change than those at the surface.

"However by the end of the century, assuming we have a high-emissions future, there is not only much greater surface warming, but also this warmth will penetrate deeper," Mr Brito-Morales said.

"In waters between a depth of 200 and 1000 metres, our research showed climate velocities accelerated to 11 times the present rate.

"And in an interesting twist, not only is climate velocity moving at different speeds at different depths in the ocean, but also in different directions which poses huge challenges to the ways we design protected areas."

Senior researcher UQ's Professor Anthony Richardson said the team believed action must be taken to aggressively manage carbon emissions.

"Significantly reducing carbon emissions is vital to control warming and to help take control of climate velocities in the surface layers of the ocean by 2100," he said.

"But because of the immense size and depth of the ocean, warming already absorbed at the ocean surface will mix into deeper waters.

"This means that marine life in the deep ocean will face escalating threats from ocean warming until the end of the century, no matter what we do now.

"This leaves only one option - act urgently to alleviate other human-generated threats to deep-sea life, including seabed mining and deep-sea bottom fishing.

"The best way to do this is to declare large, new protected areas in the deep ocean where damage to ocean life is prohibited, or at least strictly managed."
-end-
The research has been published in Nature Climate Change (DOI: 10.1038/s41558-020-0773-5).

The global team included UQ's Dr Carissa Klein, UQ PhD candidate Mr Nur Arafeh-Dalmau, Professor David Schoeman from the University of the Sunshine Coast, Hokkaido University's Assistant Professor Jorge García Molinos, and Professor Michael Burrows from the Scottish Association for Marine Science. Additional collaborators included members of the AquaMaps team.

University of Queensland

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.