Nav: Home

Study confirms steady warming of oceans for past 75 years

January 04, 2017

Scientists have solved a puzzling break in continuity of ocean warming records that sparked much controversy after climate data was published in the journal Science in 2015.

The latest research from the Universities of York, UK, and California, Berkeley, US, confirms that the conclusions of the National Oceanic and Atmospheric Administration's (NOAA) research paper, which sparked wide debate following the suggestion that there was no detectable slowdown in ocean warming, were in fact accurate.

The 2015 analysis by NOAA scientists showed that ocean buoys now used to measure water temperatures tend to report slightly cooler temperatures than older ship-based systems. As buoy measurements have replaced ship measurements, this had hidden some of the real-world warming.

Scientists corrected this 'cold bias' and concluded that oceans have actually warmed 0.12 degrees Celsius per decade since 1997, nearly twice as fast as earlier estimates of 0.07 degrees Celsius per decade. This brought the rate of ocean temperature rise in line with estimates for the previous 50 years, between 1950 and 1999.

Many scientists, including the International Panel on Climate Change, acknowledged the 'global warming hiatus', while those dubious about the science pointed to it as evidence that climate change is a hoax. The new study, which uses independent data from satellites and robotic floats as well as buoys, concludes that the NOAA results were correct.

Dr Kevin Cowtan, from the University of York's Department of Chemistry, said: "Replication is an important part of science, but is often unrewarded - everyone wants to get the big new result rather than checking old ones. In this case the political controversy which was manufactured around the NOAA paper provided a strong motivation for doing the study.

"We were initially sceptical of the NOAA result, because it showed faster warming than a previous updated record from the UK Met Office. So we set out to test it for ourselves, using different methods and different data. We now think NOAA got it right, and a new dataset from the Japan Meteorological Agency also agrees."

Historically mariners measured the ocean temperature by scooping up a bucket of water from the ocean and sticking a thermometer into it. In the 1950s, however, ships began to automatically measure water piped through the engine room, which is typically warm.

Nowadays, buoys cover much of the ocean and that data is beginning to supplant ship data. The buoys report slightly cooler temperatures because they measure water directly from the ocean instead of after a trip through a warm engine room.

Zeke Hausfather, a graduate student in UC Berkeley's Energy and Resources Group, said: "Only a small fraction of ocean measurements are being used by climate monitoring groups, and they are trying to combine data together from different instruments, which leads to a lot of judgement calls about how you weight one over the other, and how you adjust for the transition from one to another.

"So we created a temperature record just from the buoys, or just from the satellites, or just from the Argo floats, so there was no mixing and matching of instruments."

Using data from only one instrument type - either satellite, buoys or Argo floats - the results matched those of the NOAA group, supporting the case that the oceans warmed 0.12 degrees Celsius per decade over the past two decades.

This means that the upward trend seen in the last half of the 20th century continued through the first 15 years of the 21st - there was no sudden 'break' from global warming.
-end-
The research, funded by Berkeley Earth, is published in Science Advances.

University of York

Related Climate Change Articles:

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.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

How to Win Friends and Influence Baboons
Baboon troops. We all know they're hierarchical. There's the big brutish alpha male who rules with a hairy iron fist, and then there's everybody else. Which is what Meg Crofoot thought too, before she used GPS collars to track the movements of a troop of baboons for a whole month. What she and her team learned from this data gave them a whole new understanding of baboon troop dynamics, and, moment to moment, who really has the power.  This episode was reported and produced by Annie McEwen. Support Radiolab by becoming a member today at Radiolab.org/donate.