Has global warming stopped? No - it’s just on pause, insist scientists, and it's down to the oceans

Temperatures still expected to reach predicted 2015 levels with only a five-year delay after 12 of the 14 hottest years on record

Science Editor

Huge amounts of heat – equivalent to the power of 150 billion electric kettles – are being continuously absorbed by the deep ocean, which could explain why global warming has “paused” over the past 10 to 15 years, scientists have concluded in a series of reports to explain why the Earth’s rate of warming has slowed down.

Global average temperatures are higher now than they have ever been since modern records began. However, after a period of rapid temperature increases during the 1980s and 1990s there has been a significant slow-down since the turn of the century, leading some sceptics to claim that global warming has stopped.

A scientific assessment of the planet’s heat balance has found that the most likely explanation for the recent hiatus in global warming is the continual absorption of thermal energy by the huge “heat sink” of the deep ocean many hundreds of metres below the sea surface, according to scientists from the Met Office.

Senior climate scientists said that they had always expected periods when the rate of increase in temperatures would level off for a few years and emphasised that the last decade was still warmer than any previous decade, with 12 of the 14 hottest years on record occurring since 2000.

Professor Rowan Sutton, a climate scientist at Reading University, said the temperatures have levelled off in the past, the latest example being in the 1940s and 1950s when sulphate pollutants from the post-war boom in industrial production may have acted as a shield against incoming solar radiation.

“Some people call it a slow-down, some call it a hiatus, some people call it a pause. The global average surface temperature has not increased substantially over the last 10 to 15 years,” Professor Sutton said.

“Climate scientists absolutely expect variations in the rate at which surface temperature will rise….but that is not to say we understand all the details of the last 10 to 15 years,” Professor Sutton said.

The problem for the Met Office is to explain why the rate of increase in global temperatures has declined in recent years while concentrations of carbon dioxide in the atmosphere have continued to accelerate. Sceptics claim that this shows there is not a strong link between the two, whereas climate scientists insist that rising carbon dioxide concentrations are largely responsible for the rise in global temperatures.

Professor Stephen Belcher, head of the Met Office Hadley Centre, said that a pause in the rate of increase in global temperatures lasting this long is unusual but not exceptional, with similar pauses of about 10 years expected on average twice every century.

The most likely explanation for the current pause is that excess heat trapped by carbon dioxide in the atmosphere is being transferred from the atmosphere to the oceans where it is being transported down to deeper layers that cannot be monitored by satellites, Professor Belcher said.

“It looks like the Earth is continuing to accumulate energy but it looks like it is being re-arranged and hidden from view,” he said.

However, measurements from hundreds of ocean floats released over the last decade, which descend and drift to depths of up to 2,000 metres, show that huge amounts of heat from the sea surface is now being transferred to the deep ocean, with unknown consequences for the environment, the scientists said.

“In summary, observations of ocean heat content and of sea-level rise suggest that the Earth system has continued to absorb heat energy over the past 15 years, and that this additional heat has been absorbed in the ocean,” says the Met Office report.

The pause, however, is unlikely to change the predictions over the future course of global warming. Temperature increases expected by 2015 will only be delayed by a further five or ten years, the scientists said. Average surface temperatures are still on course to increase by 2C this century, with further rises expected by the end of the century if nothing is done to curb carbon dioxide emissions, they said.

It is not possible to account for the recent lack of surface warming solely by looking at the difference between amount of heat being received from the Sun and the amount of thermal energy being lost from the planet – calculations show that extra heat continues to be absorbed by the Earth at a rate of 0.6 Watts per square metre, equivalent to about 300bn 1KW electric heaters or 150bn 2KW kettles distributed across the planet.

“Observations of ocean heat content and of sea-level rise suggest that the additional heat from the continued rise in atmospheric carbon dioxide concentrations has been absorbed in the ocean and has not been manifest as a rise in surface temperature,” the Met Office says in one of its three reports into the global warming pause.

“Radiated forcing by greenhouse gases has continued unabated; that heat is being held in the system but is not manifest as a rise in global mean surface temperature. Observations of ocean heat content and of sea-level rise suggest that this additional heat has been absorbed by the ocean,” it says.

PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
News
ebooksAn evocation of the conflict through the eyes of those who lived through it
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

C# Developer (Genetic Algorithms, .NET 4.5, TDD, SQL, AI)

£40000 - £60000 per annum + Benefits + Bonus: Harrington Starr: C# Developer (...

C# Full Stack Developer (.NET 4.0, ASP.NET, MVC, Ajax, WCF,SQL)

£55000 - £65000 per annum + Benefits + Bonus: Harrington Starr: C# Full Stack ...

AIFMD Business Analyst / Consultant - Investment Management

£450 - £600 per day: Harrington Starr: AIFMD Business Analyst / Consultant - I...

Business Analyst Solvency II SME (Pillar 1, 2 & 3) Insurance

£450 - £600 per day: Harrington Starr: Business Analyst Solvency II SME (Pilla...

Day In a Page

Middle East crisis: We know all too much about the cruelty of Isis – but all too little about who they are

We know all too much about the cruelty of Isis – but all too little about who they are

Now Obama has seen the next US reporter to be threatened with beheading, will he blink, asks Robert Fisk
Neanderthals lived alongside humans for centuries, latest study shows

Final resting place of our Neanderthal neighbours revealed

Bones dated to 40,000 years ago show species may have died out in Belgium species co-existed
Scottish independence: The new Scots who hold fate of the UK in their hands

The new Scots who hold fate of the UK in their hands

Scotland’s immigrants are as passionate about the future of their adopted nation as anyone else
Culture Minister Ed Vaizey: ‘lack of ethnic minority and black faces on TV is weird’

'Lack of ethnic minority and black faces on TV is weird'

Culture Minister Ed Vaizey calls for immediate action to address the problem
7 best quadcopters and drones

Flying fun: 7 best quadcopters and drones

From state of the art devices with stabilised cameras to mini gadgets that can soar around the home, we take some flying objects for a spin
Andy Murray: I quit while I’m ahead too often

Andy Murray: I quit while I’m ahead too often

British No 1 knows his consistency as well as his fitness needs working on as he prepares for the US Open after a ‘very, very up and down’ year
Ferguson: In the heartlands of America, a descent into madness

A descent into madness in America's heartlands

David Usborne arrived in Ferguson, Missouri to be greeted by a scene more redolent of Gaza and Afghanistan
BBC’s filming of raid at Sir Cliff’s home ‘may be result of corruption’

BBC faces corruption allegation over its Sir Cliff police raid coverage

Reporter’s relationship with police under scrutiny as DG is summoned by MPs to explain extensive live broadcast of swoop on singer’s home
Lauded therapist Harley Mille still in limbo as battle to stay in Britain drags on

Lauded therapist still in limbo as battle to stay in Britain drags on

Australian Harley Miller is as frustrated by court delays as she is with the idiosyncrasies of immigration law
Lewis Fry Richardson's weather forecasts changed the world. But could his predictions of war do the same?

Lewis Fry Richardson's weather forecasts changed the world...

But could his predictions of war do the same?
Kate Bush asks fans not to take photos at her London gigs: 'I want to have contact with the audience, not iPhones'

'I want to have contact with the audience, not iPhones'

Kate Bush asks fans not to take photos at her London gigs
Under-35s have rated gardening in their top five favourite leisure activities, but why?

Young at hort

Under-35s have rated gardening in their top five favourite leisure activities. But why are so many people are swapping sweaty clubs for leafy shrubs?
Tim Vine, winner of the Funniest Joke of the Fringe award: 'making a quip as funny as possible is an art'

Beyond a joke

Tim Vine, winner of the Funniest Joke of the Fringe award, has nigh-on 200 in his act. So how are they conceived?
The late Peter O'Toole shines in 'Katherine of Alexandria' despite illness

The late Peter O'Toole shines in 'Katherine of Alexandria' despite illness

Sadly though, the Lawrence of Arabia star is not around to lend his own critique
Wicken Fen in Cambridgeshire: The joy of camping in a wetland nature reserve and sleeping under the stars

A wild night out

Wicken Fen in Cambridgeshire offers a rare chance to camp in a wetland nature reserve