People like duality. Hitler is bad. Mother Teresa is good. Finger pointing is one of the best ways humans separate themselves from others, whether the identifier is a religious affiliation; a lifestyle choice; a cultural preference; a political view; or a sports team. Amazingly this need to belong to a certain 'side' funnels right down to the insignificance of choices like whether one drinks Coca Cola or Pepsi. Let's face it, life is easier if we can label things and then pick our camp. Then we know where we belong and depending on our choices the finger pointing can be as laid back or radical as we like. I remember I once worked for a boss who drank Pepsi. Being a Diet Coke drinker I just couldn't wrap my head around the idea that I worked for 'one of them', loyalty to my brand was so fierce that I even lost some respect for my boss because he drank the 'weaker' beverage. Division is a force to be reckoned with, but that's a subject for the anthropologists to discuss, not me.
However, on the point of division, I have started to think that the need for duality is why things get messy when it comes to the subject of climate change. With some education it becomes obvious that there is no clear option to finger point at because it's not a black or white issue, it's a complex issue that desperately needs clarifying in straight terms and perhaps one day I will be lucky enough to come across that article (and will repost it here). Until then I must make do with my own research and rational mind to sift through all the information out there. I'm not a specialist on the subject, but I do spend considerable time learning about it and have discovered a few things that affect our climate beyond the human CO2 issue, things that hardly get any attention outside of science journals.
What is amazing is what the journals discuss is so interesting I can't understand why they aren't getting any press time. I have also read articles where experts talk about mother nature having the upper hand and what we are doing to the planet is insignificant compared to what she can do. And probably they are right. How can we really know the pattern unless we live and keep meticulous records for at least 14,000 years - the approximate time it takes between ice age cycles? All we can do is measure in terms of our own limited human scope, and even if we mass together all our historical information on the weather and the climate, we will only be able to gather up data from at most the last several hundred years. Worse, most of the information comes from a narrow slice of the world, since records were only kept in Europe and then later on in America. It is only within the last few decades that we have had any real global data of the climate so we are talking a drop in the cooling ocean when it comes to actual, relevant data. So that's worrying. How can we really, reliably know what is happening to our climate if we don't have any benchmarks to work against?
It's a tough question. And one that the anti climate change folks have jumped on and used against the people who are trying to address what is happening on our planet. But taking a step back, losing the need for duality and choosing a 'side', what happens if we forget about the bias and just consider the facts?
Today I got up and walked my dog, the morning which greeted me was beautiful, crisp and clear with a temperature around zero. The air was clean and fresh and all around me were blue skies and sunshine. As I walked, I pondered the question of climate change. It seemed ridiculous, given the lovely weather that there could be anything to worry about at all. The future felt safe and certain as I walked. The world won't change will it? Just like you, I have much at stake to lose if things suddenly go wrong. In order of vulnerability, I have a home, animals who depend on me and a partner I care deeply about. It's much to lose. Then I thought about the recent flood victims in Australia, and Brazil, and throughout the countries of southern Africa and steeled myself to go on, fighting the good fight of finding unbiased, honest information about what climate change really encompasses. It's one thing to jump on a bandwagon, half-informed and brainwashed by sensationalist media and shout about climate change without really understanding what it is, and quite another to make it your unpaid, full-time employment to quietly research and blog about it. I do this because I care about the planet. I also do this because I hope that somehow my blog will inspire others to see our world in shades of grey and take the time to inform themselves knowledgeably about this issue.
So let's get onto looking at the natural causes for climate change. It's a huge subject and I wanted to get at least the major natural causes summed up in one blog. However, for those of you who prefer a recap, let it suffice to say that the contributing natural cause factors are diverse and within each of them lies their own inherent complexity. To combine all the factors together and draw any reasonable conclusion would require a Herculean effort. What is even more frustrating is that the data we have accumulated is far too young to provide us with any solid guidelines as to the cyclical nature of most of them, so for the most part scientists and academics are forced to make best guesses. The bottom line? Trust your instincts and enjoy every day we have. No one really knows what is happening for sure. But it doesn't hurt to get smart either.
nb. I have merely copied and pasted the information below leaving it to the experts to say it best, and have sourced my information after each entry.
Ice Ages / Glacial Ages
"Within the ice ages (or at least within the current one), more temperate and more severe periods occur. The colder periods are called glacial periods, the warmer periods interglacials, such as the Eemian Stage.
Glacials are characterized by cooler and drier climates over most of the Earth and large land and sea ice masses extending outward from the poles. Mountain glaciers in otherwise unglaciated areas extend to lower elevations due to a lower snow line. Sea levels drop due to the removal of large volumes of water above sea level in the icecaps. There is evidence that ocean circulation patterns are disrupted by glaciations. Since the Earth has significant continental glaciation in the Arctic and Antarctic, we are currently in a glacial minimum of a glaciation. Such a period between glacial maxima is known as an interglacial.
The Earth has been in an interglacial period known as the Holocene for more than 11,000 years. It was conventional wisdom that "the typical interglacial period lasts about 12,000 years," but this has been called into question recently. For example, an article in Nature argues that the current interglacial might be most analogous to a previous interglacial that lasted 28,000 years. Predicted changes in orbital forcing suggest that the next glacial period would begin at least 50,000 years from now, even in absence of human-made global warming (see Milankovitch cycles). Moreover, anthropogenic forcing from increased greenhouse gases might outweigh orbital forcing for as long as intensive use of fossil fuels continues. At a meeting of the American Geophysical Union (December 17, 2008), scientists detailed evidence in support of the controversial idea that the introduction of large-scale rice agriculture in Asia, coupled with extensive deforestation in Europe began to alter world climate by pumping significant amounts of greenhouse gases into the atmosphere over the last 1,000 years. In turn, a warmer atmosphere heated the oceans making them much less efficient storehouses of carbon dioxide and reinforcing global warming, possibly forestalling the onset of a new glacial age." Source
The Great Conveyor Belt by Thom Hartmann
"If enough cold, fresh water coming from the melting polar ice caps and the melting glaciers of Greenland flows into the northern Atlantic, it will shut down the Gulf Stream, which keeps Europe and northeastern North America warm. The worst-case scenario would be a full-blown return of the last ice age - in a period as short as 2 to 3 years from its onset - and the mid-case scenario would be a period like the "little ice age" of a few centuries ago that disrupted worldwide weather patterns leading to extremely harsh winters, droughts, worldwide desertification, crop failures, and wars around the world."
El Niño and La Niña
"El Niño/La Niña-Southern Oscillation, or ENSO, is a quasi-periodic climate pattern that occurs across the tropical Pacific Ocean with on average five year intervals. It is characterized by variations in the temperature of the surface of the tropical eastern Pacific Ocean - warming or cooling known as El Niño and La Niña respectively - and air surface pressure in the tropical western Pacific - the Southern Oscillation. The two variations are coupled: the warm oceanic phase, El Niño, accompanies high air surface pressure in the western Pacific, while the cold phase, La Niña, accompanies low air surface pressure in the western Pacific. Mechanisms that cause the oscillation remain under study.
ENSO causes extreme weather such as floods, droughts and other weather disturbances in many regions of the world. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. In popular usage, the El Niño-Southern Oscillation is often called just "El Niño". El Niño is Spanish for "the boy" and refers to the Christ child, because periodic warming in the Pacific near South America is usually noticed around Christmas. The expression of ENSO is potentially subject to dramatic changes as a result of global warming, and is a target for research in this regard.
El Niño is defined by prolonged differences in Pacific Ocean surface temperatures when compared with the average value. The accepted definition is a warming or cooling of at least 0.5 °C (0.9 °F) averaged over the east-central tropical Pacific Ocean. Typically, this anomaly happens at irregular intervals of 2–7 years and lasts nine months to two years. The average period length is 5 years. When this warming or cooling occurs for only seven to nine months, it is classified as El Niño/La Niña "conditions"; when it occurs for more than that period, it is classified as El Niño/La Niña "episodes".
The first signs of an El Niño are:
- Rise in surface pressure over the Indian Ocean, Indonesia, and Australia
- Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean
- Trade winds in the south Pacific weaken or head east
- Warm air rises near Peru, causing rain in the northern Peruvian deserts
- Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.
El Niño's warm rush of nutrient-poor tropical water, heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current. When El Niño conditions last for many months, extensive ocean warming and the reduction in Easterly Trade winds limits upwelling of cold nutrient-rich deep water and its economic impact to local fishing for an international market can be serious. Source
La Niña causes mostly the opposite effects of El Niño, for example, El Niño would cause a wet period in the Midwestern U.S., while La Niña would typically cause a dry period in this area. At the other side of the Pacific La Niña can cause heavy rains. For India, an El Niño is often a cause for concern because of its adverse impact on the south-west monsoon; this happened in 2009. A La Niña, on the other hand, is often beneficial for the monsoon, especially in the latter half. The La Niña that appeared in the Pacific in 2010 probably helped last year's south-west monsoon end on the favourable note. But then, it also contributed to the deluge in Australia, which resulted in one of that country's worst natural disasters with large parts of the north-east under water. It wreaked similar havoc in south-eastern Brazil and played a part in the heavy rains and consequent flooding that have affected Sri Lanka." Source
"Orbital forcing is the effect on climate of slow changes in the tilt of the Earth's axis and shape of the orbit (see Milankovitch cycles). These orbital changes change the total amount of sunlight reaching the Earth by up to 25% at mid-latitudes (from 400 to 500 Wm-2 at latitudes of 60 degrees). In this context, the term "forcing" signifies a physical process that affects the Earth's climate.
This mechanism is believed to be responsible for the timing of the ice age cycles. A strict application of the Milankovitch theory does not allow the prediction of a "sudden" ice age (rapid being anything under a century or two), since the fastest orbital period is about 20,000 years. The timing of past glacial periods coincides very well with the predictions of the Milankovitch theory, and these effects can be calculated into the future.
Today, northern hemisphere summer is 4.66 days longer than winter and spring is 2.9 days longer than autumn. As axial precession changes the place in the Earth's orbit where the solstices and equinoxes occur, Northern hemisphere winters will get longer and summers will get shorter, eventually creating conditions believed to be favorable for triggering the next glacial period.
The arrangements of land masses on the Earth's surface are believed to reinforce the orbital forcing effects. Comparisons of plate tectonic continent reconstructions and paleoclimatic studies show that the Milankovitch cycles have the greatest effect during geologic eras when landmasses have been concentrated in polar regions, as is the case today. Greenland, Antarctica, and the northern portions of Europe, Asia, and North America are situated such that a minor change in solar energy will tip the balance between year-round snow/ice preservation and complete summer melting. The presence of snow and ice is a well-understood positive feedback mechanism for climate." Source
"Large, explosive volcanic eruptions inject water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and ash (pulverized rock and pumice) into the stratosphere to heights of 16–32 kilometres (10–20 mi) above the Earth's surface. The most significant impacts from these injections come from the conversion of sulfur dioxide to sulfuric acid (H2SO4), which condenses rapidly in the stratosphere to form fine sulfate aerosols. The aerosols increase the Earth's albedo—its reflection of radiation from the Sun back into space – and thus cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere. Several eruptions during the past century have caused a decline in the average temperature at the Earth's surface of up to half a degree (Fahrenheit scale) for periods of one to three years — sulfur dioxide from the eruption of Huaynaputina probably caused the Russian famine of 1601 - 1603.
One proposed volcanic winter happened c. 70,000 years ago following the supereruption of Lake Toba on Sumatra island in Indonesia. According to the Toba catastrophe theory to which some anthropologists and archeologists subscribe, it had global consequences, killing most humans then alive and creating a population bottleneck that affected the genetic inheritance of all humans today. The 1815 eruption of Mount Tambora created global climate anomalies that became known as the "Year Without a Summer" because of the effect on North American and European weather. Agricultural crops failed and livestock died in much of the Northern Hemisphere, resulting in one of the worst famines of the 19th century. The freezing winter of 1740–41, which led to widespread famine in northern Europe, may also owe its origins to a volcanic eruption.
It has been suggested that volcanic activity caused or contributed to the End-Ordovician, Permian-Triassic, Late Devonian mass extinctions, and possibly others. The massive eruptive event which formed the Siberian Traps, one of the largest known volcanic events of the last 500 million years of Earth's geological history, continued for a million years and is considered to be the likely cause of the "Great Dying" about 250 million years ago, which is estimated to have killed 90% of species existing at the time.
The sulfate aerosols also promote complex chemical reactions on their surfaces that alter chlorine and nitrogen chemical species in the stratosphere. This effect, together with increased stratospheric chlorine levels from chlorofluorocarbon pollution, generates chlorine monoxide (ClO), which destroys ozone (O3). As the aerosols grow and coagulate, they settle down into the upper troposphere where they serve as nuclei for cirrus clouds and further modify the Earth's radiation balance. Most of the hydrogen chloride (HCl) and hydrogen fluoride (HF) are dissolved in water droplets in the eruption cloud and quickly fall to the ground as acid rain. The injected ash also falls rapidly from the stratosphere; most of it is removed within several days to a few weeks. Finally, explosive volcanic eruptions release the greenhouse gas carbon dioxide and thus provide a deep source of carbon for biogeochemical cycles.
Rainbow and volcanic ash with sulfur dioxide emissions from Halema`uma`u vent.Gas emissions from volcanoes are a natural contributor to acid rain. Volcanic activity releases about 130 to 230 teragrams (145 million to 255 million short tons) of carbon dioxide each year. Volcanic eruptions may inject aerosols into the Earth's atmosphere. Large injections may cause visual effects such as unusually colorful sunsets and affect global climate mainly by cooling it. Volcanic eruptions also provide the benefit of adding nutrients to soil through the weathering process of volcanic rocks. These fertile soils assist the growth of plants and various crops. Volcanic eruptions can also create new islands, as the magma cools and solidifies upon contact with the water.
Ash thrown into the air by eruptions can present a hazard to aircraft, especially jet aircraft where the particles can be melted by the high operating temperature. Dangerous encounters in 1982 after the eruption of Galunggung in Indonesia, and 1989 after the eruption of Mount Redoubt in Alaska raised awareness of this phenomenon. Nine Volcanic Ash Advisory Centers were established by the International Civil Aviation Organization to monitor ash clouds and advise pilots accordingly. The 2010 eruptions of Eyjafjallajökull caused major disruptions to air travel in Europe." Source
Originally published on Paradigms Bend Jan 24 2011