Posted on 15 August 2011 by Mythago

It seems that every month there comes more news of droughts, floods and fires all over the planet. But a lot of people seem to be stuck in the mindset that if it isn’t happening in their backyard then it’s just someone else’s problem and as long as it remains elsewhere then there is nothing to worry about. It’s business as usual.

Until the heat hits the high 90’s-low 100’s for weeks on end there is always this sense of apathy about what our actions are doing to the climate and in what particular way we are causing global warming. Even the term ‘Global Warming’ is seldom used by the big science culture these days for fear of inciting ridicule because of freak cold snaps in isolated areas, which as regular readers already know are not representative of the overall global temperature trend.

To illustrate how the greenhouse gas emissions are affecting the planets climate requires an assessment of their concentrations, their residency time, and their energy trapping impact on the larger planetary climate.

CO2 is the most widely known and talked about greenhouse gas *(See Note at end of paragraph), but what people don’t quite get is why it is? They also don’t fully understand how much of an impact it really has. Add the other greenhouse gases such as methane and nitrous oxide to the conversation and you start seeing people’s eyes glaze over and the shutters go down. They simply don’t get it and if they don’t get it they won’t do anything about it either, which is bad news for everyone.

*Note:This is apart from water vapour which is also a greenhouse gas, but for the basis of this article water vapour is not being considered here. I want to look at the anthropogenic greenhouse gases to explore the potential that exists for them to be reduced by the greater population and not just the factories or other industrial outlets.

So what we need is a neat little visual diagram which shows the various ratio’s of greenhouse gases, their impact and their duration on the climate change front. Add to this a little data on the sources of these individual greenhouse gas emissions and the general public will have a resource they can use to enable them to be more effective at reducing their climate footprint, one that even the kids can understand. Not an easy task with the masses of climate change data to churn through first.

So which Greenhouse Gases are present in the atmosphere?

The National Oceanic and Atmospheric Administration (NOAA) has created a graphical representation of the differing proportions of greenhouse gases and how they impact on the planet individually in terms of warming influence. They also include the other less well known greenhouse gases. What may come as a surprise though is just how long some of these other gases actually hang around up there doing their thermal blanket job and how much heat they will retain on the planet.

Figure 1 Proportions of greenhouse gases by Warming Influence (watts/m2). The direct warming influence of all long-lived greenhouse gases in the atmosphere today attributable to human activities. CO₂’s warming influence of 1.7 watts/m2 is equivalent to the heat from nearly 9 trillion 100-watt incandescent light bulbs placed across Earth’s surface. The combined influence of the non-CO₂ greenhouse gases is equivalent to the heat from about 5 trillion bulbs. The category “other “includes a few very long-lived chemicals that can exert a climate influence for millennia.

The pie chart clearly shows that CO2 makes up the lions share of greenhouse gas emissions yet it is not the most potent of the family. In my search for additional data on longevity and the heat trapping impact of these particular gases I discovered a fact that I hadn’t come across before and that is how long we have actually known about the greenhouse effect? It was first ‘discovered by Joseph Fourier in 1824, (it was) first reliably experimented on by John Tyndall in 1858, and first reported quantitatively by Svante Arrhenius in 1896.’ (Source Wikipedia: http://en.wikipedia.org/wiki/Greenhouse_effect) That’s a long time knowing about something and not actually getting around to doing anything to prevent its build-up. Thinking time is a luxury we nolonger have in terms of the impacts now occurring and the long term trends which we need to address.

So what about their lifecycles in the atmosphere? How long do they hang around for? I came across the following chart listing the main greenhouse gases with an indication of their residency in the atmosphere:

http://green.yahoo.com/blog/climate411/80/how-long-do-greenhouse-gases-last.html

As the associated article states, "CO2 is the most difficult gas to actually account for because it is involved in more than one natural recycling process. Most of the CO2 is dissolved into the oceans over a few decades but the remainder is taken up by numerous other processes which vary dramatically in their duration from a few decades to many thousands of years."

This means that the CO2 can remain in the atmosphere for 50 to 500 + years. The geological cycle is known to take many thousands of years to complete.

With some of the more exotic gases their lifetime can be extremely long. Being man-made they can tend to endure for many years in an inert state but as has been discovered what at first was thought of as an inert gas can become a serious problem in the atmosphere. This was indeed the case with CFC's. Though inert at sea level, when exposed to the extreme cold atmospheric conditions and the ultra-violet radiation above the polar regions they soon reacted with ozone. The seriousness of this problem was not entirely understood until the 1980's.

The exotic gases that remain intact for a very long time have various effects on the atmpsphere.  Some of them cause major climatic issues for a very long time.

A number of these gases are used in household and car air conditioning units, refrigerators, fire retardants and even in the production of a number of insulation materials that are intended to reduce the impact of our energy use. Gases like HFC's and HCFC's are supposed to be less ozone destructive having been created as a replacement for CFC's. For more information on the list of greenhouse gases so far assessed go to: http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/133.htm

Nitrous Oxide is a common byproduct of agriculture as a result of excessive nitrogen fertiliser applications and can remain in the atmosphere for 120 years. It is 310 times more powerful as a greenhouse heat trapping gas than CO2. http://www.epa.gov/nitrousoxide/scientific.html

The main source for this gas emission is agriculture but it is also emitted by home gardens where keen individuals attempt to grow lush vegetation with little or no understanding of the importance of timing of the applications of such chemicals.

Methane has a potency of around 25 times that of CO2 yet it remains in the atmosphere for only around 12 years. This may seem like a small risk factor but the reality is that the tipping of environmental balances will probably occur as a result of increased Methane and not from the longer term CO2 emissions. This is where the warming effect on the Arctic Tundra is becoming a grave concern. The mass of frozen peat is now decomposing as it thaws and releasing massive volumes of methane into the atmosphere. With such a large influence in terms of its potency it will not need to be around for the real climatic damage to be done and a tipping point reached.

http://en.wikipedia.org/wiki/Arctic_methane_release

If the amount released is only half this volume the impact would still lead to about 400% of indirect forcing.

 http://www.agu.org/pubs/crossref/2011/2010GB003845.shtml 

What is the most effective way to reduce our Greenhouse Gas impact?

Figure 2: The direct radiative forcing (warming effect) of greenhouse gases under various scenarios. a) Red: constant 2008 emissions of both CO₂ and non-CO₂ greenhouse gases. b) An 80% cut in non-CO₂ emissions. c) An 80% cut in CO₂ emissions. d) An 80% cut in all greenhouse gas emissions. In all scenarios, emissions cuts are phased in between 2009 and 2050.

The above chart from NOAA indicates how much of an impact reduction of the various gas types will have on the climate. Having no reductions is not an option. Just cutting out the Non-CO2 sources only marginally reduces climate change yet these gases are more common in the home and garden. The article associated with the charts does not suggest that this approach would be a waste of time. It does suggest however that the general public, who for a long time have felt disassociated from the climate change debate, now have a way to make a valuable contribution to climate change and greenhouse gas reduction. They can now selectively change the component parts of their lifestyles to reduce energy use, reduce component pollution and introduce new habits to their family units that they would never have considered effective before.

The gases they can reduce the usage of form part of the coolant in refrigeration and air conditioning units in both their homes and cars. There are also numerous chemical cleaners that only exist in the homes which are made with processes that create carbon emissions. The use of fertilisers in the garden instead of using home produced compost has a dire impact on the atmosphere. By changing the way we garden we can contain the carbon emissions within the garden environment by trapping them in the vegetation and trees. The Rodale Institute has determined that up to 40% of our current global emissions could be sequestered if the world adopted organic agriculture. This is far preferable to sending our compostable waste to landfill where it will slowly emit methane. There are many landfill initiatives where the green waste is composted and reused in some ways but this is still a limited process. In fact some is sent to biomass power stations and this is not the most environmentally sustainable way of dealing with it.

Also of concern are the fire retardants in the home furnishings. These are a source of greenhouse gases like HFC’s and have also been linked with numerous serious health conditions. Strange that we are concerned about our homes catching fire but don’t seem to care that the planet is fast burning up. Maybe it’s an omen.

So what is the solution?

The only way to really see a reduction in the impact of greenhouse gases is to reduce the entire range of greenhouse gas emissions regardless of source. This is why it is becoming increasingly important to present the evidence in a manner which can be understood by the vast majority of the population. Not by manipulating data as has been suggested by some of the denial community but by simplifying the terms of reference so it makes easy sense.

A final suggestion would be to use more visual aids like this pie chart to give some kind of physical perspective to the reality of this situation. If we said that there is 35% more CO2 in 2005 than there was before the industrial revolution people would have no grasp of what that meant. By putting these figures into a visual form the proportions of the problem become more apparent. Add to this an easy way to identify the sources and a selection of alternatives that allow people to continue living their lives without any dramatic changes or reductions in their flexibility to live but with major reductions in climate impact and you will have an effective method of making a contribution to the reduction of carbon that goes way beyond what the governments and the corporations are willing to implement today.

Further information on the greenhouse gases and the impact of climate change can be found at the following sites:

http://www.epa.gov/nitrousoxide/sources.html

The source and inspiration for the article was derived from an NOAA article.

This site gives a listing of the numerous sources of GHG’s in simple descriptive terms.