Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



CLIMATE SCIENCE
Is the Earth warming? The ocean gives you the answer
by Staff Writers
Beijing, China (SPX) Sep 15, 2017


Ocean heat content (OHC) and CO2 concentration measurements since 1950s. The black line represents ocean heating for the upper 2000 meters of ocean, and light red shading represents the 95 percent confidence interval. CO2 concentration observed in Mauna Loa Observatory is displayed by light blue. Image courtesy Lijing Cheng.

Humans have released carbon dioxide and other greenhouse gases, and the result is an accumulation of heat in the Earth's climate system, commonly referred to as "global warming". "How fast is the Earth's warming?" is a key question for decision makers, scientists and general public.

Previously, the global mean surface temperature has been widely used as a key metric of global warming. However, a new study published in AGU's Eos proposed a better way of measuring global warming: monitoring ocean heat content change and sea level rise. The authors come from a variety of international communities including China (Institute of Atmospheric Physics, Chinese Academy of Sciences), U.S.A. (NCAR, NOAA, and University of St. Thomas) and France (Mercator Ocean).

To determine how fast the Earth is accumulating heat, scientists focus on the Earth's energy imbalance (EEI): the difference between incoming solar radiation and outgoing longwave (thermal) radiation. Increases in the EEI are directly attributable to human activities that increase carbon dioxide and other greenhouse gases in the atmosphere. Extra heat trapped by increasing greenhouse gases mainly ends up in the oceans (more than 90% is stored there). Hence, to measure global warming, we have to measure ocean warming!

On the other hand, the amplitude of the global warming signal compared with natural variability (noise) defines how well a metric tracks global warming. This study shows that the temporal evolution of ocean heat content has relatively high signal-to-noise ratio; therefore, it requires 3.9 years to separate the global warming trend from natural variability.

Similarly, for sea level rise, 4.6 years are sufficient to detect the climate change signal. By contrast, owing to weather, El Nino - Southern Oscillation and other natural variability embedded in the global mean surface temperature record, scientists need at least 27 years of data to detect a robust trend. An excellent example is the 1998-2013 period, when energy was redistributed within the Earth's system and the rise of global mean surface temperature slowed - sometimes call a "hiatus".

This study suggests that changes in ocean heat content, the dominant component of Earth's energy imbalance, should be a fundamental metric along with sea level rise.

Based on the recent improvements of ocean monitoring technologies, especially after 2005 through autonomous floats called Argo, and advanced methodologies to reconstruct the historical ocean temperature record, scientists have been able to quantify ocean heat content changes back to 1960, even though there is a much sparser historical instrument record prior to 2005. Sea level rise is best known since 1993 when altimeters were first launched on satellites to enable sea level change observations to millimeter accuracy.

According to the most up-to-date estimates, the top-10 warmest years of the ocean (indicated by OHC change at upper 2000m) are all in the most recent decade after 2006, with 2015-2016 the warmest period among the past 77 years.

The heat storage in the ocean amounts to an increase of 30.4+ 1022 Joules (J) since 1960, equal to a heating rate of 0.33 Watts per square meter (W m-2) averaged over the entire Earth's surface - and 0.61 W m-2 after 1992. For comparison, the increase in ocean heat content observed since 1992 in the upper 2000 meters is about 2000 times the total net generation of electricity by U.S. utility companies in 2015.

It is evident that scientists and modelers who seek global warming signals should track how much heat the ocean has stored at any given time, i.e. ocean heat content, as well as sea level rise.

Locally, in the deep tropics, ocean heat content directly relates to hurricane activity. Ocean heat content is a vital sign of our planet and informs societal decisions about adaptation to and mitigation of climate change.

CLIMATE SCIENCE
Pope slams climate change deniers as 'stupid'
On Board The Papal Plane (AFP) Sept 11, 2017
Pope Francis on Monday slammed climate change doubters as "stupid" in the wake of a spate of hurricanes that have thrashed the US, Mexico and the Caribbean. "Those who deny it (climate change) should go to the scientists and ask them. They are very clear, very precise," the pontiff said Monday during a press conference on the return leg of a five-day Colombia trip. "A phrase from the Old ... read more

Related Links
Institute of Atmospheric Physics, Chinese Academy of Sciences
Climate Science News - Modeling, Mitigation Adaptation


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

CLIMATE SCIENCE
Voyager Spacecraft: 40 Years of Solar System Discoveries

Trump names former Navy aviator to head NASA

What's hot and what's not at Berlin's IFA tech fair

'Star Trek' actor Shatner sends message to Voyager

CLIMATE SCIENCE
Rocket fever launches UB students to engineering competition in New Mexico

NASA Concludes Summer of Testing with Fifth Flight Controller Hot Fire

ISRO suspects pyro elements failed to separate rocket's heat shield

Ariane 5 rocket aborts Guiana lift-off in final seconds

CLIMATE SCIENCE
Discovery of boron on Mars adds to evidence for habitability

Life on Mars: Let's Try Oman Desert First for Space Mission

Citizen scientists spot Martian 'spiders' in unexpected places

Big dishes band together

CLIMATE SCIENCE
China, Russia to Have Smooth Space Cooperation, Says Expert

Kuaizhou-11 to send six satellites into space

Russia, China May Sign 5-Year Agreement on Joint Space Exploration

ESA and Chinese astronauts train together

CLIMATE SCIENCE
Bids for government funding prove strong interest in LaunchUK

Blue Sky Network Reaffirms Commitment to Brazilian Market

India to Launch Exclusive Satellite for Afghanistan

Lockheed Martin invests $350M in state-of-the-art satellite production facility

CLIMATE SCIENCE
New microscopy method for quick and reliable 3-D imaging of curvilinear nanostructures

Chinese video site offers virtual escape from 'boring' reality

Chinese video site offers virtual escape from 'boring' reality

Molecules move faster near sticky surfaces

CLIMATE SCIENCE
Could interstellar ice provide the answer to birth of DNA

Climate change for aliens

X-Rays Reveal Temperament of Possible Planet-Hosting Stars

Earth as Hybrid Planet: The Anthropocene Era in Astrobiological Context

CLIMATE SCIENCE
Pluto features given first official names

Jupiter's Auroras Present a Powerful Mystery

New Horizons Files Flight Plan for 2019 Flyby

Juno Scientists Prepare for Seventh Science Pass of Jupiter




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement