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Climate Change: Human Disaster Looms, Says Research

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By Fiona Harvey, The Guardian

Some of the most extreme predictions of global warming are unlikely to materialize, new scientific research has suggested, but the world is still likely to be in for a temperature rise of double that regarded as safe.

The researchers said warming was most likely to reach about 4C above pre-industrial levels if the past decade's readings were taken into account.

Warming may still lead to catastrophe across large swaths of the Earth, causing droughts, storms, floods and heat waves, and drastic effects on agricultural productivity.
Credit: Patrick Pleul/EPA

That would still lead to catastrophe across large swaths of the Earth, causing droughts, storms, floods and heat waves, and drastic effects on agricultural productivity leading to secondary effects such as mass migration.

Some climate change skeptics have suggested that because the highest global average temperature yet recorded was in 1998 climate change has stalled. The new study, which is published in the journal Nature Geoscience, shows a much longer "pause" would be needed to suggest that the world was not warming rapidly.

Alexander Otto, at the University of Oxford, lead author of the research, told the Guardian that there was much that climate scientists could still not fully factor into their models. He said most of the recent warming had been absorbed by the oceans but this would change as the seas heat up. The thermal expansion of the oceans is one of the main factors behind current and projected sea level rises.

The highest global average temperature ever recorded was in 1998, under the effects of a strong El Niño, a southern Pacific weather system associated with warmer and stormy weather, which oscillates with a milder system called La Niña. Since then the trend of average global surface temperatures has shown a clear rise above the long-term averages – the 10 warmest years on record have been since 1998 – but climate skeptics have claimed that this represents a pause in warming.

Otto said that this most recent pattern could not be taken as evidence that climate change has stopped. "Given the noise in the climate and temperature system, you would need to see a much longer period of any pause in order to draw the conclusion that global warming was not occurring," he said. Such a period could be as long as 40 years of the climate record, he said.

Otto said the study found that most of the climate change models used by scientists were "pretty accurate." A comprehensive global study of climate change science is expected to be published in September by the Intergovernmental Panel on Climate Change, its first major report since 2007.

The trend of average global surface temperatures has shown a clear rise above the long-term averages – the 10 warmest years on record have been since 1998.
Credit: flickr/Global Jet

Jochem Marotzke, professor at the Max Planck Institute for Meteorology in Hamburg and a co-author of the paper, said: "It is important not to over-interpret a single decade, given what we know, and don't know, about natural climate variability. Over the past decade the world as a whole has continued to warm but the warming is mostly in the subsurface oceans rather than at the surface."

Other researchers also warned that there was little comfort to be taken from the new estimates – greenhouse gas emissions are rising at a far higher rate than had been predicted by this stage of the 21st century and set to rise even further, so estimates for how much warming is likely will also have to be upped.

Richard Allan, reader in climate at the University of Reading, said: "This work has used observations to estimate Earth's current heating rate and demonstrate that simulations of climate change far in the future seem to be pretty accurate. However, the research also indicates that a minority of simulations may be responding more rapidly towards this overall warming than the observations indicate."

He said the effect of pollutants in the atmosphere, which reflect the sun's heat back into space, was particularly hard to measure.

He noted the inferred sensitivity of climate to a doubling of carbon dioxide concentrations based on this new study, suggesting a rise of 1.2C to 3.9C, was consistent with the range from climate simulations of 2.2C to 4.7C. He said: "With work like this our predictions become ever better."

Reprinted with permission from The Guardian

Comments

By Eric Peterson (Front Royal, VA 22630)
on May 26th, 2013

“The researchers said warming was most likely to reach about 4C above pre-industrial levels if the past decade’s readings were taken into account.”

Including the recent slowdown, warming is about 0.13C per decade so to get to that 4C (assuming 0.7C so far) will take 200 years or more.  Also warming doesn’t “cause” storms, drought, etc. What warming will do with certainty is exacerbate drought and heatwaves.  With somewhat less certainty it will increase tropical storm intensity.  For nontropical storms, dynamical ingredients are more important than warmth.  Warming doesn’t cause blocking meaning that droughts, heatwaves and prolonged rainfalls start and end naturally.  However warming will exacerbate all of those.

As for the warming hiding in the ocean, if they mean the deep ocean it means warming will take centuries.  The deep ocean is being warmed (in theory) from a few degrees above freezing to a bit warmer than that.  We are lucky in that we have a planet cooling deep ocean currents originating in the Arctic.  Even if those currents are a little warmer, they still cool.

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By Gerald Mathias (N Hollywood, Ca 91606)
on May 27th, 2013

THE SOLUTION IS MASSIVE AWARENESS OF THE IMPORTANCE OF BIRTH CONTROL ON A WORLD-WIDE SCALE. THE EARTH’S HUMAN POPLUATION IS OVER 9 BILLION AND RAPIDLY INCREASING. YOU CANT’T HAVE THAT MANY PEOPLE GENERATING HEAT AND POLLUTION, FISHING OUT THE OCEANS AND DE-FORESTING THE PLANET AND NOT EXPECT CATASTROPHIC CONSEQUENCES. HUMANS ARE RAPIDLY OVER-POPULATING THIS PLANET, AND NO ONE IS PAYING ATTENTION.

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By Robert Fields (Rabun Gap, GA)
on May 27th, 2013

I recently watched an interview by Bill Moyers with a Yale University Climate Science spokesman who gave broke down 6 categories of Climate Science “personalities” in the US. I believe he said there are 16% of Americans (40 million) who feel like I do, this is the biggest problem we face today but we, just like the most credible peer reviewed scientist (97% +),  are being ignored by the media (40% of the worIds citizens have never heard the term “climate change”) believe it is a combination of the media giving (except for Fox News “entertainment) what they feel is equal time to those in the “I’m not sure” camp, and the overwhelming group who are in the know. This leads to a public that becomes confused and just think this is “science” problem so they’ll just let the scientist work it out amongst themselves. Of course we know the oil and coal industries are really to blame, they are using the same strategy that was employed in the tobacco issue to cause confusion and cloud the issue at hand, you know by law it is their job to their share holders- regardless if results in mass extinction, to guard their bottom line. It may be too late already, but the people responsible for the campaign to deny should ultimately be brought up on charges of genocide.

Robert Fields

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By GK (kerala)
on May 27th, 2013

All the information provided are both true and facts….........................

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