One of the paradoxes of climate change is that we are all so tied up with the situation of carbon emissions that we have tended to forget one issue that is worse than carbon and that is methane emission.
Over millions of years methane has emitted into the atmosphere and when it reaches a certain level it creates an atmospheric reaction thus causing a rapid increase in global temperature thus causing a ice age. A paradox but the mechanics that occur in nature are never simple. Methane is emitted from a number of bio-mass situations from certain declines in rotting vegetation to BI-product of animal waste and that includes us. Methane is actually worse than carbon in that it does not get stored in varying other areas in nature like permafrost layers and the intake of trees through a process of conversion through the leaves. That's the reason why the carbon levels in the northern hemisphere rise during late autumn and winter till the leaves reappear then it declines once again. Unfortunately not as fast as before as we are always adding to the amount in the air.
Methane however is accumulating and is a nasty commodity that does create global warming. And is on the increase!
One of the research areas therefore should be the methane equation! If methane was responsible in the past along with carbon and we have a higher amount in the atmosphere of carbon now than ever before and a ice age occurred back then.
Then what is the missing element? Why have we not gone into another ice age now like before if carbon increase was the cause?
The reason is the methane equation! Methane gas is emitting in areas all over the planet and as our population grows and we invade more land mass and produce more decay in vegetation and waste we increase the output of methane, we breed cattle for consumption and so the cattle population increases. Both manure using straw and cattle waste is mixed for fertilization of soil as we demand more food production so fields are not allowed to lay fallow and so methane emission rises.
Worth considering don't you think!
And how are our methane emission values today compared with say the beginning of the last global climate change, anyone want to hazard a guess!
Here is a recent report courtesy of wikipedia.
Recent rates of change and emission
The sharp acceleration in CO2 emissions since 2000 of >3% y-1 (>2 ppm y-1) from 1.1% y-1 during the 90's is attributable to the lapse of formerly declining trends in carbon intensity of both developing and developed nations. Although over 3/4 of cumulative anthropogenic CO2 is still attributable to the developed world, China was responsible for most of global growth in emissions during this period. All this indicates a global failure to decarbonise energy supply and an underestimation of emissions growth on the part of the IPCC in their Special Report on Emissions Scenarios. Localized plummeting emissions associated with the collapse of the Soviet Union have been followed by slow emissions growth in this region due to more efficient energy use, made necessary by the increasing proportion of it that is exported. In comparison, methane has not increased appreciably, and N2O by 0.25% y-1.
The United States emitted 16.3% more GHG in 2005 than it did in 1990. According to a preliminary estimate by the Netherlands Environmental Assessment Agency, the largest national producer of CO2 emissions since 2006 has been China with an estimated annual production of about 6200 megatonnes. It is followed by the United States with about 5,800 megatonnes. Relative to 2005, China's fossil CO2 emissions of China increased in 2006 by 8.7%, while in the USA, comparable CO2 emissions decreased in 2006 by 1.4%. The agency notes that its estimates do not include some CO2 sources of uncertain magnitude.
However the results do give another story that needs to be addressed.
This is a report from NASA and this section is of interest as it not only mentions the methane equation but also helps us piece the puzzle together.......
Courtesy NASA Earth Report. (Link to full report!)
But what the researchers actually found is not such a clear-cut climate story.
Permafrost collapse in peatlands tends to result in the slumping of the soil surface and flooding, followed by a complete change in vegetation, soil structure, and many other important aspects of these ecosystems, Turetsky said. The study showed that vegetation responds to the flooding with a boost in productivity. More vegetation sequesters more carbon away from the atmosphere in plant biomass.
"This is actually good news from a greenhouse gas perspective," Turetsky said.
However, the report also cautions that this flooding associated with collapsing permafrost also increases methane emissions. Methane is an important greenhouse gas, which is more powerful than carbon dioxide in its ability to trap heat in the earth's atmosphere.
The report actually shows us how this nasty gas can escape through an increase of carbon heating the atmosphere thus free methane from its natural stored environment through global warming.
The question remains however of if we experienced an ice age with less carbon in the air than before. Then why is the carbon so much higher now and we are not experiencing the ice age like before.
The reason is firstly that methane can convert to CO2 by the following process:
As a consequence of chemical reactions within the atmosphere. This is the case for methane. It is oxidized by reaction with naturally occurring hydroxyl radical, OH· and degraded to CO2 and water vapor at the end of a chain of reactions (the contribution of the CO2 from the oxidation of methane is not included in the methane Global warming potential). This also includes solution and solid phase chemistry occurring in atmospheric aerosols.
The life-span of methane is shown in the next example:
Examples of the atmospheric lifetime and GWP for several greenhouse gases include:
- · CO2 has a variable atmospheric lifetime, and cannot be specified precisely. Recent work indicates that recovery from a large input of atmospheric CO2 from burning fossil fuels will result in an effective lifetime of tens of thousands of years. Carbon dioxide is defined to have a GWP of 1 over all time periods.
- · Methane has an atmospheric lifetime of 12 ± 3 years and a GWP of 62 over 20 years, 23 over 100 years and 7 over 500 years. The decrease in GWP associated with longer times is associated with the fact that the methane is degraded to water and CO2 by chemical reactions in the atmosphere.
- · Nitrous oxide has an atmospheric lifetime of 120 years and a GWP of 296 over 100 years.
- · CFC-12 has an atmospheric lifetime of 100 years and a GWP(100) of 10600.
- · HCFC-22 has an atmospheric lifetime of 12.1 years and a GWP(100) of 1700.
- · Tetrafluoromethane has an atmospheric lifetime of 50,000 years and a GWP(100) of 5700.
- · Sulfur hexafluoride has an atmospheric lifetime of 3,200 years and a GWP(100) of 22000.
The answer is what happens to the carbon when the methane takes over in the atmosphere re global climate control. The answer is a rapid increase in carbon values.
Its a cocktail of trouble! And we need to find an answer and fast!
The answers are always in front of use but we usually always as humans spend more time disbelieving that anything is wrong rather than become aware of our interactive impact on the global biosphere. We live in a bubble and its an air type we need as humans to become aware that we are not invincible nor immune to being wiped out by our own inaction!
Here is another report of just how methane works...Full report here!
Methane as a Greenhouse Gas
First some basics: methane (CH4) is a very simple molecule (one carbon surrounded by four hydrogen atoms) and is created predominantly by bacteria that feed on organic material. In dry conditions, there is plenty of atmospheric oxygen, and so aerobic bacteria which produce carbon dioxide (CO2) are preferred. But in wet areas such as swamps, wetlands and in the ocean, there is not enough oxygen, and so complex hydrocarbons get broken down to methane by anaerobic bacteria. Some of this methane can get trapped (as a gas, as a solid, dissolved or eaten) and some makes its way to the atmosphere where it is gradually broken down to CO2 and water (H2O) vapor in a series of chemical reactions.
Although methane was detected in the atmosphere in 1948, its importance to climate was only recently revealed by three key discoveries. The first, by Wei-Chyung Wang and colleagues at NASA GISS in 1976, was that methane in the atmosphere was actually a significant greenhouse gas — it absorbs some frequencies of infrared radiation (emitted from the Earth's surface) that would otherwise go straight out to space. In combination with other greenhouse gases (water vapor, CO2 and N2O), this leads to a surface temperature that is about 30°C warmer than if there were no atmosphere.
The second key result was due to the recovery and analyses of Greenland and Antarctic ice cores. These multi-kilometer cores, drilled through the ice sheets by both European and American research teams, have shown in unprecedented detail climate changes over centuries, millennia, and hundreds of thousands of years. Indeed, annual layers can be discerned for much of the length of the cores, which allowed researchers to construct an extremely accurate timescale for the climate-related changes they found.
Along with isotopic analyses of the ice itself (which is mainly related to temperature), the researchers (such as Jérôme Chappellaz in Grenoble, France) were able to isolate the gases trapped inside tiny bubbles in the ice. The greenhouses gases, CO2 and CH4, within those bubbles showed that since the industrial period began (around the mid-1800s) concentrations of both CO2 and CH4 have been increasing rapidly. In fact, CH4 concentrations have more than doubled over the last 150 years, and the contribution to the enhanced greenhouse effect is almost half of that due to CO2 increases over the same period.
The changes over the last century seem to be mostly related to increased emissions due to human activity: leaks from mining and natural gas pipelines, landfills, increased irrigation (particularly rice paddies, which are essentially artificial wetlands) and increased livestock producing more intestinal CH4 (!) among other factors. However, over the last ice age, and particularly in the turbulent world just prior to the modern Holocene period (roughly the last 11,500 years), methane was observed to oscillate almost hand-in-hand in response to rapid climate changes such as the Younger Dryas cold interval (a return to almost full ice age conditions 12,500 years ago).
Click on any figure below to view a larger version.
As shown by a chemistry "ball and stick" model, a methane molecule is composed of one atom of carbon surrounded by four atoms of hydrogen.
Rough schematic of methane sources and sinks. (Image: NASA GISS)
Natural sources of methane include wetlands, termites, decomposing organic materials in ocean and fresh water, and methane hydrate. Anthropogenic influenced sources include livestock flatulence, rice paddies, biomass burning, landfills, coal mining, and gas production, with rice paddies and livestock flatulence being the major sources of methane. (Image: U.S. Dept. of Energy Technology Laboratory, National Methane Hydrate Program)
Methane Sensitivity to Climate
The third key piece of evidence was an exceptional investigation by Jeff Severinghaus of Scripps Institution of Oceanography and Ed Brook of Washington State University. They convincingly showed (using some novel geochemistry involving the isotopes of nitrogen that react to rapid changes in surface temperatures) that methane rapidly increases in a warming climate with a small lag behind temperature. Therefore, not only does methane affect climate through greenhouse effects, but it in turn can evidently be affected by climate itself.
With these observations — that methane is a greenhouse gas, that changes to emissions can affect the atmospheric concentration, and that climate can cause methane emissions to vary — there is a potential for some very interesting positive feedbacks. The question then turns to what controls this variability and how large these effects can be. Researchers have only started to delve into the details necessary to understand the links more thoroughly.
This is where the interesting link is re methane and sudden rise in global condition!!
With a plausible role for methane clathrates in the Paleocene, it is only natural to examine whether they played a similar role in more recent climate changes, such as rapid climate variability during the last ice age. There are some tantalizing clues. In ocean sediments offshore of California, Kai-Uwe Hinrichs and colleagues at Woods Hole recently found geochemical traces of clathrate releases coincident with warmings in the Greenland ice core records. In some records, there are coincident spikes in the carbon isotope record, reminiscent of the Paleocene/Eocene spike but of lower amplitude. This has lead Jim Kennett to propose the so-called "clathrate gun hypothesis", that methane builds up in clathrates during cold periods, and as a warming starts it is explosively released, leading to enhanced further rapid climate warming. This idea is not yet widely accepted, mainly because the records of methane in the ice cores seems to lag the temperature changes, and the magnitudes involved do not appear large enough to significantly perturb the radiative balance of the planet. The more conventional explanation is that as the climate warms there is increased rain in the tropics and thus increased emissions from tropical wetlands which need to have been large enough to counteract a probable increase in the methane sink. There is, however, much that we don't understand about the methane cycle during the ice ages, and maybe hydrates will eventually be considered part of the rapid climate change story.
One aspect that was not considered in this report was the sudden release of methane quantities from permafrost levels melting as previously discussed. Tie this into the equation and the increase of methane along with the already high concentrations of CO2 and warmer atmosphere and we have the cocktail.
And if you don't believe then do the numbers!
Now just to finish off this from Signonsandiego.com and
By measuring methane in ancient ice, researchers hope to piece together clues from past climate shifts
By Bruce Lieberman
UNION-TRIBUNE STAFF WRITER
Ice sheets in Greenland and Antarctica are archives of global climate history because the planet's atmosphere mixes quickly. A spike in atmospheric methane caused by a warming in the tropics, for example, can be captured in air bubbles trapped in Greenland ice within a year.
In fact, Severinghaus and his colleagues studying the abrupt warming 11,600 years ago have found evidence in the ice that shows a spike in methane in the years following the temperature rise.
Spikes in global atmospheric methane coincide with other historic rises in temperature, suggesting that its rise is an integral part of rapid and dramatic shifts in world climate.
Where that methane comes from and how it can drive further global temperature increases are important questions for climate scientists. Methane, a key greenhouse gas, is 25 times more potent than carbon dioxide in its ability to trap the sun's heat. Scientists hope to learn about past rises in atmospheric methane in order to figure out how a modern rise in methane might occur, and what the result would be for Earth's future climate.
Researchers have focused on two possible sources for the methane spikes at the end of the last ice age.
One is from wetlands, in the tropics and elsewhere, that would have developed in a warmer and wetter world.
The other is under the ocean, along continental shelves where methane hydrates – ice-like solids made of methane and water – in sediments could have destabilized and released methane gas into the atmosphere.
Keep in mind that CH4 warms the atmosphere suddenly if large amounts are released and this in turn melts the ice increasing the fresh water flow into the oceans thus changing the Gulf stream and others thus shutting down the ocean dynamo. Plus through conversation if time produces C02.
Warming trends will occur from methane increase on both sides of the ice age so the spike makes sense at the end of the ice age period due to the reduction of content as well as the melting as warming begins in a more natural fashion plus methane will convert over time so the sudden increase of temperature is due to melting ice, reduction of methane after the spike as well as Co2 plus reduction of sun reflection from both the surface as well as the polluted atmosphere.
Plus the re-warming of the oceans will increase activity in consumption of methane so the reduction with be fast.
The reason why we are not seeing another ice age yet due to the double value of Co2 in the start of the last ice age as many have stated is because the methane level is not the same as before. Co2 does not deflect as well as methane so the values of both are different only in the methane levels. That could change quickly if the methane reserves in the permafrost were released which by the way has already started.
So if methane was high at the start of the ice age and stayed around it may have reduced enough to cause a slight warming which created the spike at the end of the ice age. This scenario can exist on both sides of the equation. before and after as well as during....
Dr Jon Sherwood