Paul

Published Online September 27, 2007
Science DOI: 10.1126/science.1143791

Southern Hemisphere and Deep-Sea Warming Led Deglacial Atmospheric CO2 Rise and Tropical Warming

Lowell Stott 1*, Axel Timmermann 2, Robert Thunell 3

1 Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA.
2 IPRC, SOEST, University of Hawaii, 2525 Correa Road, HI 96822, USA.
3 Department of Geological Sciences, University of South Carolina, Columbia, SC 29208, USA.

Establishing what caused Earth’s largest climatic changes in the past requires a precise knowledge of both the forcing and the regional responses. Here we establish the chronology of high and low latitude climate change at the last glacial termination by 14C dating benthic and planktonic foraminiferal stable isotope and Mg/Ca records from a marine core collected in the western tropical Pacific. Deep sea temperatures warmed by ~2C between 19 and 17 ka B.P. (thousand years before present), leading the rise in atmospheric CO2 and tropical surface ocean warming by ~1000 years. The cause of this deglacial deep water warming does not lie within the tropics, nor can its early onset between 19-17 ka B.P. be attributed to CO2 forcing. Increasing austral spring insolation combined with sea-ice albedo feedbacks appear to be key factors responsible for this warming.

Summary at EurekAlert

Extract:

Deep-sea temperatures rose 1,300 years before atmospheric CO2, ruling out the greenhouse gas as driver of meltdown, says study in Science. Carbon dioxide did not cause the end of the last ice age, a new study in Science suggests, contrary to past inferences from ice core records. “There has been this continual reference to the correspondence between CO2 and climate change as reflected in ice core records as justification for the role of CO2 in climate change,” said USC geologist Lowell Stott, lead author of the study, slated for advance online publication Sept. 27 in Science Express. “You can no longer argue that CO2 alone caused the end of the ice ages.” Deep-sea temperatures warmed about 1,300 years before the tropical surface ocean and well before the rise in atmospheric CO2, the study found. The finding suggests the rise in greenhouse gas was likely a result of warming and may have accelerated the meltdown – but was not its main cause. The study does not question the fact that CO2 plays a key role in climate. I don’t want anyone to leave thinking that this is evidence that CO2 doesn’t affect climate,” Stott cautioned. “It does, but the important point is that CO2 is not the beginning and end of climate change.” While an increase in atmospheric CO2 and the end of the ice ages occurred at roughly the same time, scientists have debated whether CO2 caused the warming or was released later by an already warming sea. The best estimate from other studies of when CO2 began to rise is no earlier than 18,000 years ago. Yet this study shows that the deep sea, which reflects oceanic temperature trends, started warming about 19,000 years ago. “What this means is that a lot of energy went into the ocean long before the rise in atmospheric CO2,” Stott said. But where did this energy come from” Evidence pointed southward. Water’s salinity and temperature are properties that can be used to trace its origin – and the warming deep water appeared to come from the Antarctic Ocean, the scientists wrote. This water then was transported northward over 1,000 years via well-known deep-sea currents, a conclusion supported by carbon-dating evidence. In addition, the researchers noted that deep-sea temperature increases coincided with the retreat of Antarctic sea ice, both occurring 19,000 years ago, before the northern hemisphere’s ice retreat began. Finally, Stott and colleagues found a correlation between melting Antarctic sea ice and increased springtime solar radiation over Antarctica, suggesting this might be the energy source. As the sun pumped in heat, the warming accelerated because of sea-ice albedo feedbacks, in which retreating ice exposes ocean water that reflects less light and absorbs more heat, much like a dark T-shirt on a hot day. < > “The climate dynamic is much more complex than simply saying that CO2 rises and the temperature warms,” Stott said. The complexities “have to be understood in order to appreciate how the climate system has changed in the past and how it will change in the future.”

Nature 449, 382-383 (27 September 2007)

Chemists poke holes in ozone theory

Quirin Schiermeier

Reaction data of crucial chloride compounds called into question.

Extract:

As the world marks 20 years since the introduction of the Montreal Protocol to protect the ozone layer, Nature has learned of experimental data that threaten to shatter established theories of ozone chemistry. If the data are right, scientists will have to rethink their understanding of how ozone holes are formed and how that relates to climate change.

Long-lived chloride compounds from anthropogenic emissions of chlorofluorocarbons (CFCs) are the main cause of worrying seasonal ozone losses in both hemispheres. In 1985, researchers discovered a hole in the ozone layer above the Antarctic, after atmospheric chloride levels built up. The Montreal Protocol, agreed in 1987 and ratified two years later, stopped the production and consumption of most ozone-destroying chemicals. But many will linger on in the atmosphere for decades to come. How and on what timescales they will break down depend on the molecules’ ultraviolet absorption spectrum (the wavelength of light a molecule can absorb), as the energy for the process comes from sunlight. Molecules break down and react at different speeds according to the wavelength available and the temperature, both of which are factored into the protocol.

So Markus Rex, an atmosphere scientist at the Alfred Wegener Institute of Polar and Marine Research in Potsdam, Germany, did a double-take when he saw new data for the break-down rate of a crucial molecule, dichlorine peroxide (Cl2O2). The rate of photolysis (light-activated splitting) of this molecule reported by chemists at NASA’s Jet Propulsion Laboratory in Pasadena, California, was extremely low in the wavelengths available in the stratosphere — almost an order of magnitude lower than the currently accepted rate. “This must have far-reaching consequences,” Rex says. “If the measurements are correct we can basically no longer say we understand how ozone holes come into being.” What effect the results have on projections of the speed or extent of ozone depletion remains unclear.

The abstract of the original paper is here.

CCNet’s take:

CCNet 161/2007 – 27 September 2007 — Audiatur et altera pars

SCIENTIFIC CONSENSUS ON MAN-MADE OZONE HOLE MAY BE COMING APART

As the world marks 20 years since the introduction of the Montreal Protocol to protect the ozone layer, Nature has learned of experimental data that threaten to shatter established theories of ozone chemistry. If the data are right, scientists will have to rethink their understanding of how ozone holes are formed and how that relates to climate change.
–Quirin Schiermeier, News@Nature, 26 September 2007

If the measurements are correct we can basically no longer say we understand how ozone holes come into being.
–Markus Rex, News@Nature, 26 September 2007

Our understanding of chloride chemistry has really been blown apart.
–John Crowley, Max Planck Institute of Chemistry, 26 September 2007

Until recently everything looked like it fitted nicely. Now suddenly it’s like a plank has been pulled out of a bridge.
–Neil Harris, University of Cambridge, 26 September 2007

The new measurements raise “intriguing questions”, but don’t compromise the Montreal Protocol as such, says John Pyle, an atmosphere researcher at the University of Cambridge. “We’re starting to see the benefits of the protocol, but we need to keep the pressure on.” He says that he finds it “extremely hard to believe” that an unknown mechanism accounts for the bulk of observed ozone losses.
–Quirin Schiermeier, News@Nature, 26 September 2007

James Lovelock’s plan to pump ocean water to stop climate change is reported in the UK’s Daily Telegraph today, 27th September.

A plan to save our world from extreme climate change by pumping cold water from the depths of the oceans is outlined today by James Lovelock, the scientist who inspired the greens.

James Lovelock is best known for his ideas that portray Earth as a living thing, a super-organism – named Gaia, after the ancient Earth goddess – in which creatures, rocks, air and water interact in subtle ways to ensure the environment remains stable.

Today Lovelock, of Green College, Oxford University, outlines an emergency way to stimulate the Earth to cure itself with Chris Rapley, former head of the British Antarctic Survey who is now the director of the Science Museum, London.

They believe the answer lies in the oceans, which transport much more heat than the atmosphere and, covering more than 70 per cent of the Earth’s surface.

They propose that vertical pipes some 10 metres across be placed in the ocean, such that wave motion would pump up cool water from 100-200 metres depth to the surface, moving nutrient-rich waters in the depths to mix with the relatively barren warm waters at the ocean surface.

This would fertilise algae in the surface waters and encourage them to bloom, absorbing carbon dioxide greenhouse gas while also releasing a chemical called dimethyl sulphide that is know to seed sunlight reflecting clouds.

Read more.

The article is derived from Lovelock and Rapley’s correspondence in this weeks Nature magazine.

The following article appered in The Sunday Times on 23rd September: The ‘carbon offset’ child labourers, Indians work off West’s holiday guilt.

Extracts:

Pumping furiously on a foot treadle in the afternoon heat, six-year-old Sarju Ram is irrigating her impoverished family’s field, improving the crop and – without knowing it – helping environmentally sensitive holiday-makers assuage their guilt over long-haul flights to dream destinations.

But Sarju and her four brothers and sisters working flat out in a clump of trees that provide scant shelter from the sun illustrate a growing argument over claims that British environmentalists’ efforts to curb greenhouse emissions are inadvertently fuelling an increase in child labour.

Sarju’s family is a beneficiary of Climate Care, an organisation that helps some of Britain’s leading public figures and companies to offset their carbon dioxide emissions by funding sustainable energy projects.

Customers of British Airways are among those who have been encouraged to log on to Climate Care’s website and calculate how many tonnes of greenhouse gases their flights will generate, and how much it will cost to neutralise the impact on the atmosphere. A flight to Barbados for a family of four, for example, generates 7.55 tonnes of carbon dioxide, which will cost them £56.64 to offset.

Climate Care uses the money to help persuade families such as Sarju’s to give up labour-saving diesel pumps and buy human-powered treadles instead. It claims that by using the treadle, a family will save money on diesel and hire charges, earn more from increased crops and cut the carbon emissions that would have been produced by the pump.

Last week Indian experts criticised the scheme, saying it was promoting child labour and forcing poor farmers to work harder so that wealthy air travellers could enjoy exotic holidays without worrying about the environment.

“The problem is the number of times child labour is involved,” claimed Ashutosh Pandey of Emergent Ventures India, which advises companies on clean technology.

“It’s not being monitored properly. It’s not reducing emissions. People are selling their diesel pumps to others who are using them.”

Michael Buick, a spokesman for the Oxford-based Climate Care, confirmed that children were working the pumps it promotes, but said that people had to focus on the benefits to the whole family.

He said his group was proud of its scheme, which had led to more than half a million foot treadles being sold, and had won several awards. Four reports had identified major benefits.

According to Buick, critics are mistaken in claiming that diesel pumps are better than human-powered alternatives, because they are costly to run. The treadles meant farmers could rely on increased crops.

Buick said that by “all mucking in” families were able to increase yields and earn more to pay for children to go to school. The extra income also meant fathers could stay with their families rather than leaving them to look for work in the cities.

“If mum is planting and harvesting, the daughters help out. It’s just a different way of life. The phrase ‘child labour’ is emotive. It implies factories, but these are family farms where everyone gets stuck in, watering the crops and taking a turn on the treadle pump,” he said.

One of the essential prerequisites for the IPCC case for extended global warming is the claim that we face an extended Holocene because orbital geometry now is similar to the 400KY (Stage 11) interglacial which lasted for 28, 000 years.

Based on the paper by Berger and Loutre (2003) it is claimed that the extraordinarily long Stage 11 interglacial period resulted from the low orbital eccentricity at the time, and now we have similar eccentricity and should therefore expect an extended Holocene. (IPCC TS 6.4 1.5)

It is reported that “It is very unlikely that the earth would naturally enter another ice age for at least 30 000 years” (IPCC TS 6.2.4 “Robust Findings”)

This position is completely without merit.

An analysis of FIG 1. below shows the orbital forcing during the 400KY precedent compared to the present configuration and it can be seen that we are very close now to the tipping point like that which led Stage 11 into the following ice age.

FIG.1 QUINN, LEVINE, RAYMO ET AL ORBITAL GEOMETRY VS CLIMATE
(AA) Projection at present insolation, (BB) Projection of Glaciation, (X) Paillard

The position (X) shows the insolation maximum at 427KY which triggered the Stage 11deglaciation. (Paillard 1998) The following small dip in insolation was not sufficient to reverse the warming trend . “The Interglacial thus lasts an additional precessional cycle, yielding a total duration of 28 000 years.” (IPCC 6.4.1.5)

This is the so called precedent for an extended Holocene. This is the reason given by IPCC for the “Robust Finding” that it is very unlikely that the earth would enter another ice age for at least 30 000 years. But as shown in FIG.1 there is no such change in insolation now and Solar Forcing is in rapid decline.

Projecting present Solar forcing (insolation) (AA) back to the 400KY precedent we intercept at exactly 400KY which corresponds to the collapse of the Stage 11 interglacial climate as it enters the following ice age.
The collapse of the Stage 11 interglacial occurs when the insolation decline is similar to today.

From this analysis, based on the Solar Forcing from present global geometry which has been accepted as the external signal for climate, the contention that it is very unlikely the Earth would naturally enter another Ice Age for at least 30 000 years is unsafe.

There is good reason to expect the imminent termination of the interglacial because of the coincident action of 3 major cyclic processes.

1. Insolation in rapid decline similar to the 400KY precedent.

2. We are near the end of the nominal 100KY glaciation cycle.

3. The present interglacial is near the average age for termination.

We are also witnessing some major natural processes which occur at the end of each interglacial such as the slow down of the MOC and polar ice melt.

It is time to plan for the coming Ice Age.

Peter Harris
September 2007

This article ‘Ahmadinejad: The New Boogeyman’ compares ‘Holocaust denial’ to global warming denial:

Mahmoud Ahmadinejad denies the Holocaust. Let me ask this provocative question: so what?

Of course, I understand that people have a visceral reaction to that claim. It is grossly untrue, offensive and ignorant. But we are also told how dangerous Ahmadinejad is because he doesn’t believe in the Holocaust. I fail to see that connection.

There are countless people all across the world that deny many things that are patently true — and we don’t go to war with them over it. Senator Inhofe (R-OK) denies global warming. As far as I know we are not planning on invading Oklahoma over it………

The writer seems to be ignorant of the fact that whilst the Holocaust actually happened, the global warming catastrophe is a computer modelled prediction, not a fact.