Getting Warmer? Prehistoric Climate Can Help Forecast Future Changes

Pliocene vs. modern sea surface temperature anomaly. (Credit: Image courtesy of United States Geological Survey)

The first comprehensive reconstruction of an extreme warm period shows the sensitivity of the climate system to changes in carbon dioxide (CO₂) levels as well as the strong influence of ocean temperatures, heat transport from equatorial regions, and greenhouse gases on Earth's temperature.

New data allow for more accurate predictions of future climate and improved understanding of today's warming. Past warm periods provide real data on climate change and are natural laboratories for understanding the global climate system.

Scientists examined fossils from 3.3 to 3.0 million years ago, known as the mid-Pliocene warm period. Research was conducted by the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) group, led by the U.S. Geological Survey.

"PRISM's research provides objective, unbiased data for climate modelers to better understand the environment in which we live and for decision makers to make informed adaptation and mitigation strategies that yield the greatest benefits to society and the environment," said Senior Advisor to USGS Global Change Programs Thomas Armstrong. "This is the most comprehensive global reconstruction for any warm period and emphasizes the importance of examining the past state of Earth's climate system to understand the future."

The mid-Pliocene experienced the most extreme warming over the past 3.3 million years. Global average temperatures were 2.5°C (4.5°F) greater than today and within the range projected for the 21st century by the Intergovernmental Panel on Climate Change.

"Exploring the mid-Pliocene will further understanding on the role of ocean circulation in a warming world, the impacts of altered storm tracks, polar versus tropical sensitivity, and the impacts of altered atmospheric CO₂ and oceanic energy transport systems," said USGS scientist Harry Dowsett, also lead scientist for PRISM. "We used fossils dated to the mid-Pliocene to reconstruct sea surface and deepwater ocean temperatures, and will continue research by studying specific geographic areas, vegetation, sea ice extent and other environmental characteristics during the Pliocene."

Since CO₂ levels during the mid-Pliocene were only slightly higher than today's levels, PRISM research suggests that a slight increase in our current CO₂ level could have a large impact on temperature change. Research also shows warming of as much as 18°C, bringing temperatures from -2°C to 16°C, in the high latitudes of the North Atlantic and Arctic Oceans during the mid-Pliocene. Warming in the Pacific, similar to a present day El Niño, was a characteristic of the mid-Pliocene. Global sea surface and deep water temperatures were found to be warmer than those of today, impacting the ocean's circulation system and climate. Data suggest the likely cause of mid-Pliocene warmth was a combination of several factors, including increased heat transport from equatorial regions to the poles and increased greenhouse gases.

PRISM has been chosen by the Pliocene Model Intercomparison Project of Paleoclimate Modelling Intercomparison Project Phase II as the dataset against which to run and test the performance of climate models for the Pliocene.

PRISM's primary collaborators are Columbia University, Duke University, the University of Leeds and the British Antarctic Survey.

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We’re All Getting a Lump of Coal This Xmas

Picture Credit:Avotius

EU Puts Brakes on Green Policies

In the wake of the financial crisis, some EU member states are reassesing the union’s CO2 reduction goals. To prevent a complete economic meltdown and fianancial crisis from turning into economic calamity, the European Union has pulled the emergency brake on green policies.

At last month’s EU summit in Brussels, seven eastern and central European countries, together with Italy, threatened to veto the Union’s climate pact. The rebel governments claimed that the originally agreed goal of cutting the EU’s CO2 emissions by 20% by 2020 was too expensive; economic turmoil and rising unemployment meant that implementing the CO2 goal was no longer affordable. Great Britian is poised to expand its coal mining industry, despite fears that the move will lead to a rise in climate change, increase in CO2 emissions, as well as harm the environment. The news that Britain is about to return to the age of coal is no surprise to anyone who’s been following energy developments in this country or even globally.

“The coming energy crisis is going to dwarf the financial crisis”, says the head of Shell Oil.

Coal is a dirty word in the U.S. because of its impact on the environment including CO2 emissions, mercury contamination, and other pollutants. The environmental movement has fought against new coal plants being constructed in the U.S. as well as keeping newly constructed coal plants from starting up and producing electricity. Just recently, the feds put a hold on constructing new coal fired plants and new coal plants already constructed cannot fire up and produce electricity until further notice.

Last March, a hold on government financing for all rural coal plants was implimented. Billings, Mont. - “The federal government is suspending a major loan program for coal-fired power plants in rural communities, saying the uncertainties of climate change and rising construction costs make the loans too risky.”

Picture Credit: davipt

Even with the U.S. keeping a tight rein on coal usage, it appears that other nations including China are bucking the green movement and going their own way ignoring global warming, CO2 and air pollution. China, the world’s number one polluter, will continue to have their air pollution problems because of their continued use of dirty coal, even though China is using modern up to date coal fired plants to produce electricity. From a previous Chemically Green post: " href="http://chemicallygreen.com/china-pollution-issue/" target="_blank">China May Be The Death of the Environmental Movement is becoming more true than ever before.

China Moves Ahead With Using Coal

While US activists prepare for a battle against the notion of ‘clean coal’, China’s coal industry continues to boom. A recent MIT report estimates that China’s power sector has been expanding at a rate roughly equivalent to three to four new coal-fired, 500 megawatt plants coming on line every week.

The real danger is not just the carbon emissions, but the wrong assumptions and perception that incremental solutions, protests, or stricter carbon regulations can somehow shift China’s current direction. Why worry? The gap continues to widen between what activists want to happen with the global coal industry, versus the reality of coal’s expanding role as the world’s fastest growing source of energy.

China is hungry for energy. Oil, yes. But mostly electricity. And despite its potential to become a cleantech manufacturing hub, it is likely to rely primarily on coal for the next thirty years as The People’s Daily Online reports that geologists have confirmed a massive 23 billion ton coal reserve deposit in the country’s Turfan Basin. ‘The coal mine occupies an area of over 300 square kilometers with a thickness of 169.69 meters, and a coal bearing ratio of 29%’. This is the second major reserve confirmed in the last six months.

The Reality of the Above scenario is that Coal Use Is Growing! The US Energy Information Agency Annual Report on 2008 reveals the brutal facts of coal’s use in the world’s energy sector.

The US is almost certain to confront the challenges of coal emissions, but no country is more important to this conversation than China. The US can probably absorb higher costs associated with cleaner uses of coal, but not China. As soon as the global economy comes out of this slump, China will once again fire up its coal plants. What will this mean? More pollution coming from China to the U.S. even though the U.S. maybe using clean coal if the technology is perfected. Source: The Energy Road Map

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Strong, lightweight green material could replace concrete, but contains no cement

Samples of Cenocell, a new material produced from coal ash. Material properties can be varied by controlling the chemical composition and curing time. (Georgia Tech Photo: Gary Meek)

An assistant professor in Georgia Tech’s School of Civil and Environmental Engineering, Doyoyo has developed a new structural material based on these leftovers from coal burning. Known as Cenocell, the material offers attributes that include high strength and light weight – without the use of cement, an essential ingredient of conventional concrete.
With broad potential applications and advantages such as good insulating properties and fire resistance, the “green” material could replace concrete, wood and other materials in a broad range of applications in construction, transportation and even aerospace.

“Dealing with the ash left over from burning coal is a problem all over the world,” said Doyoyo. “By using it for real applications, our process can make the ash a useful commodity instead of a waste product. It could also create new industry and new jobs in parts of the world that need them badly.”

Fly ash is composed of small particles removed from combustion gases by pollution control systems. Most of it must now be disposed of as a waste product, though certain types of fly ash can be used to replace a portion of the cement used in conventional concrete.

Cenocell, produced from either fly ash or bottom ash in a reaction with organic chemicals, requires none of the cement or aggregate – sand and rock – used in concrete. And unlike concrete, it emerges from curing ovens in final form and does not require a lengthy period to reach full strength.

“This is a new material very different from concrete,” Doyoyo said.

Because it uses what is now considered a waste material to replace cement – which generates carbon dioxide, a greenhouse gas – the new material is considered an asset to the environment. The material can have a wide range of properties that make it competitive with concrete, especially the new classes of autoclaved lightweight concrete.

For instance, specific densities range from 0.3 to 1.6, and the material can be manufactured to withstand pressures of up to 7,000 pounds per cubic inch. The properties can be controlled by choosing the proper ash particles size, chemical composition, and the curing time, which can range from three to 24 hours.

“We have a wide range in terms of texture, properties, performance and applications,” said Doyoyo. “The possibilities for this material are very broad.”

Among the potential applications for the material are:

-- Building and construction industry – infrastructure materials that provide sound, crash and fire barriers; permeable pavements; drainage fillers; ultra-light truss stiffeners, foam, wood and concrete replacements in residential and commercial buildings; and acoustical tiles. Cenocell is lighter than most “lightweight” concrete, and lightweight versions can be machined and cut with standard band saws.

-- Transportation industry – cores for shock and crash absorbers; fillers for trailer floors or b-pillars in vehicle frames.

-- Aerospace industry – ultra-light heat shielding.

-- Protective installations – fireproof blast walls or structural fillers for hazardous fluids.

Though for competitive reasons he won’t disclose the precise chemical composition of Cenocell, Doyoyo says the processing involves mixing the ash with organic chemicals. The chemical reaction produces foaming, and results in a gray slurry that resembles bread dough. The material is then placed in forms and cured in ovens at approximately 100 degrees Celsius until the desired strength is attained.
“We form a final compound through a combination of chemical and mechanical processes,” Doyoyo explained. “Once it comes out of our process, it is ready to go and does not continue to change over time.”

Unlike concrete, which remains a mixture of materials held together by chemical bonds, Cenocell is a homogenous material. The cell sizes and final strength depend on both the curing time and size of the ash particles used. Estimates suggest the material could be manufactured for an average cost of $50 per cubic yard.

Doyoyo and his research team – which also includes Paul Biju-Duvall, Julien Claus, Dereck Major, Rolan Duvvury and Josh Gresham – have so far made only small samples for testing. They are working with a Georgia-based maker of autoclaved concrete to produce larger samples for additional testing. Large-scale manufacturing could be done with the same equipment now used to make autoclaved concrete, he says.

Doyoyo will present information about the material at the inception workshop of the Resource-Driven Technology Concept Center in South Africa (RETECZA) December 1-3, 2008, and at the World of Coal Ash meeting May 4-7, 2009.

“We are focusing a lot on the construction industry,” Doyoyo said. “When this material is used to build a structure, it will save a lot of energy for heating and air conditioning because of its good insulating properties.”

A native of South Africa who was educated at the University of Cape Town, Brown University and Massachusetts Institute of Technology, Doyoyo sees value beyond the re-use of a waste material. He believes Cenocell could provide low-cost housing in developing countries and economic development impact from a new industry.

“This material could help develop communities by allowing people living near coal-burning facilities to create a new industry and new jobs,” he said. “This could be an engine of development for people who have been struggling. It really is a material with a social conscience.”

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