Saturday, September 03, 2011

Methane is Primary Greenhouse-gas and Carbon Dioxide Is Secondary Forcing Agent


By David G. Eselius

The sun’s orbit establishes Earth’s historic heating and less heating cycles while Methane (CH4) gas is the primary global warming gas forcing agent and Carbon Dioxide (CO2) is a secondary gas forcing agent.

Resulting from inadequate incorporation of the historic and current importance of Methane global warming gas, sun’s orbit, energy use, and Earth’s population growth—the UN Intergovernmental Panel on Climate Change (IPCC) is to revise global warming projections in preparation for the UN Framework Convention on Climate Change (UNFCCC) COP 17/MOP 7 meeting in Durban, South Africa‎, 28 November - 9 December 2011.

The Role of Interglacial Cycles

Earth’s 100,000 year interglacial natural temperature cycle (before there were more than 6.7 billion people on earth) was first determined by Earth’s orbit around the sun.  That is, the sun’s orbit, as identified in the equations of the Milankovitch Cycle identifies the sun’s position for Earth’s “normal average” warming and cooling with an average temperature range excursion of about 1C-1.5°C. Reference: “Milankovitch Cycle Tutorial

The sun’s orbit and resulting historic greenhouse-gas emissions are still in play. However, since the 1750 start of the Industrial Age and the adding the greenhouse-gases of more than 6.7 billion people, Earth’s Temperature Cycle has received an additional huge amount of global warming Methane and some Carbon Dioxide.  Resulting are Earth’s increased global warming temperatures above historic temperatures.  

Carbon cycle Methane gas was/is released by oceans during an interglacial warming period.  Carbon cycle Methane is returned to oceans during the cooling period, all within a historic temperature excursion of about 1-1.5°C.  Earth’s average temperature is now about 0.8 °C above interglacial high temperature warming 1-1.5°C zone.

Earth’s oceans and humans have produced 0.8 °C more global-warming-Methane-gas than during the normal warming of Earth Temperature Cycle.  Increased human CH4/CO2 resulted from the post 1750 warming cycle that is above the more than 60 million year Earth Temperature Cycle.  Now CH4 feedback seems to have a life of its own, and it is growing very rapidly and is dominating Earth’s Temperature Cycle.

To restore Earth’s temperature to the “normal” temperature range, greenhouse-gases Methane and Carbon Dioxide must be returned to interglacial greenhouse-gas range.  Not to return to Earth’s “normal average” warming and cooling zone means Earth’s biological life and a population of more than 9 billion people in 2050 are to exist while temperatures are increasing well above anything experienced for more than 60 million years.  At best, under expected extreme temperature conditions, the long-term quality of life for more than 9 billion people will be externally poor and temperature is expected to continue to rise past 2050.  

In 2050-2099, how far above “normal temperature” is unknown as well as the resulting affects upon biological life is also unknown, but has been postulated. Reference: EU’s "The 2°C target"  

Although much is unknown of the human races’ future fate, most likely, human races are terminated 2050-2099 due to global warming temperature increase.   

Methane greenhouse-gas has a newly calculated global warming potential (GWP) about 72 times greater than Carbon Dioxide.  The Methane-clathrate energy stored within oceans is more than twice of all Earth’s stores of coal, oil, and natural gas. Methane is a much greater global warming force than Carbon Dioxide. To understand current global warming, understand first the current and historic interactions that Methane has with temperature regulation.   

There are very important scientific and political misunderstandings concerning the part that Methane plays in global warming.  It time to start correcting those misunderstandings.

NOTE: Interesting to know is by how much Methane/Carbon Dioxide leads/lags Earth’s orbit perturbations around the sun (re: Milankovitch Cycle).  Analyzing Earth’s orbit (a orbital mechanics problem), temperature proxies, Methane/Carbon Dioxide supply sources, and global warming atmospheric densities will help resolve questions about cycles of interglacial and current temperature forcing.

Methane (CH4) vs. Carbon Dioxide (CO2) concentrations and global warming heating potentials determine the 1-1.5°C excursions zone.  As part of the carbon cycle, within the colder glacial periods there is ocean carbon sinking (absorbing) of the atmospheric Methane. During warmer interglacial period there is more oceans carbon sourcing (venting) of Methane.  If there were not now a large numbers of humans, the 100,000 year warm-cold-warm 1-1.5°C zone would be determined by Earth’s orbit around the sun.  Now, it is human greenhouse-gases that have “tipped” global temperature regulation to new higher levels.

Analysis of Arctic and Antarctic ice-cores provides an accurate recording of relative temperature changes and CH4/CO2 atmospheric concentrations.
"Antarctic Ice Bubbles Show CO2, Methane, at 800,000-Year Highs"
By Alex Morales - MAY 14, 2008
May 14 (Bloomberg) -- Ancient air bubbles trapped in Antarctica's ice have revealed that levels of carbon dioxide and methane in the Earth's atmosphere are at their highest in 800,000 years, two studies in the journal Nature said.
Analysis of a 3.3-kilometer (2.1-mile) ice core extended the existing record of atmospheric greenhouse-gases by 150,000 years and showed that concentrations of CO2 and methane fluctuated within bands well below today's levels.
“That range highlights the fact that man, through burning fossil fuels and land-use change, has changed the concentration of greenhouse-gases in the atmosphere in a substantial way.”
The United Nations Intergovernmental Panel on Climate Change (IPCC) last year (2007) blamed global warming on emissions of such gases and warned of increased flooding and drought as temperatures continue to rise. The team found that greenhouse-gas concentrations tracked temperature changes throughout the 800,000 years.
The amount of CO2 and methane now in the atmosphere are 28 percent and 124 percent, respectively, above their highest levels before industrialization.
The scientists uncovered the lowest measured concentration of carbon dioxide -- a value of 172 parts per million -- 667,000 years ago. The minimum value in the 650,000-year time series documented prior to today's [May 4, 2008] papers was about 180 ppm.
[NOTE: Ice-core concentration of CO2 and CH4 is determined by a direct chemical analysis of the bubbles. Temperature proxies are reconstructed from deuterium (D) readings that are within the same bubbles containing CO2 and CH4.
Deuterium is a stable, naturally occurring hydrogen isotope. Deuterium kinetic isotope effect is temperature sensitive and is used as a proxy for temperature.  The correlation between the ice-core temperature and NH4/CO2 is nearly perfect. See Reference: 650,000 year CO2, NH4, and Temperature  
Clearly, if ocean temperatures go up, less carbon dioxide and methane can be bound to the ocean waters, which are why CH4/CO2 concentration in the atmosphere goes up. The release of global warming-gases is known as out gassing. Additionally, there are very vast amounts of stored methane (methane-clathrates) in polar ocean and land regions.  As ocean and surface temperatures and ocean surface current temperatures increase, methane is out gassed, added to polar regional warming, and increased regional temperature (i.e. polar regional temperature feedback loop). The carbon cycle also absorbs Methane and Carbon Dioxide in the cooling cycle. –DGE]
The [greenhouse-gas concentrations] data came from analysis by scientists working on the European Project for Ice Coring in Antarctica (EPICA). They studied a 3,270-meter tube of ice extracted from the surrounding ice sheet from the southern continent. Bloomberg reported in February last year that the trends in the 650,000-year series had been found to stretch further back in history.
Pre-industrialization
The findings widen the CO2 range prior to industrialization to between 172 and 300 ppm. Man-made emissions have raised the atmospheric concentration of the gas to about 385 parts per million in 2007, the National Oceanic and Atmospheric Administration (NOAA) said April 23.
Methane prior to industrialization fluctuated between 350 and 800 parts per billion, according to the researchers. Present-day levels are about 1,770 ppb, they said.
“The fundamental conclusion that today's concentrations of these greenhouse-gases have no past analogue in the ice-core record remains firm,” Ed Brook, a scientist at Oregon State University, wrote in an accompanying article in Nature. “The remarkably strong correlations of methane and carbon dioxide with temperature reconstructions also stand.”
In the so-called paleo-climate archive, temperature increases typically came before gains in atmospheric carbon dioxide. That doesn't mean that CO2 doesn't act as a trigger for warming, he said.
[NOTE: Sun’s positions determine the limits of Earth’s warming and cooling. Over time, it is the warming greenhouse-gas Methane that does the “more warming” or “less warming,” depending upon the sun’s positions (re: Milankovitch Cycle). Carbon Dioxide does not have the out gas capacity of Methane.  Therefore Carbon Dioxide plays a lesser roll in temperature change.  Until after 1750, there were minimum forest clearing and burning, and human emissions for the Earth Temperature Cycle to deal with.  –DGE]
Ocean Currents
“We know that if the greenhouse-gases had not responded to the physical changes within the climate system at the end of ice ages, the planet would actually not have made the transition to warm phases.” “The warming was simply not enough without the increase of greenhouse-gases.”
Historical changes in gas levels can be attributed to alterations in ocean currents, tropical wetlands and vegetation, and the advance and retreat of polar ice sheets, locking methane up in the soil/oceans and then releasing it.
“Today, the concentration of CO2 is only marginally driven by these historical changes.” “More than 90 percent of these CO2 changes are driven directly through the emission of so-called new carbon dioxide that has not been in the climate system for the last 60 million years, because that carbon dioxide comes from fossil fuel reservoirs” that are burned for energy.
Ambitious Goals
Over the last 150 years, the concentration of CO2 has risen more than 100 times faster than any recorded change derived from the ice cores. That raises concern about whether global warming can be contained to within the +2 degrees Celsius (3.6 Fahrenheit) that the European Union is targeting, he said.
[NOTE: Over the last 150 years the concentration of CH4 has risen much faster than CO2.  –DGE]
“The speed of the increase of carbon dioxide [and methane] concentration in the atmosphere makes us conclude that climate goals such as the 2-degree Celsius goal have become now very, very ambitious goals to achieve: not impossible, but by now very ambitious.”
Fin

With the 2010 understanding of global warming, to have any reasonable 75% chance of keeping the global warming temperature rise below +2 °C — global carbon emissions (CO2) need to peak global greenhouse-gas equivalent emissions (CO2eq) by 2015-2020, and fall at least 16% worldwide by 2030 (based on 1990 levels). Additional global human and natural GHG emission-reductions are necessary beyond 2050 towards a zero carbon economy by the end of the century. To remain below a +1.5 °C threshold requires greater reductions of human global carbon emissions (CO2).

With ignorance or malice, no national leader or IPCC or UNFCCC has attempted to establish a viable national response plan to counter global warming temperature increase.  Correcting global warming is going to be hard and costly, but must be accomplished quickly.  The politicians have yet to understand global warming temperature increase and its consequences, which make starting global warming mitigation very difficult.  Tempus Fugit