Monday, January 18, 2010
Pickles in a Jar
Pickles in a Jar 1/18/2010
In the past year and a half, I have changed jobs once, held three part-time jobs, rented my home, lived with a sister, and now rent from a college professor, all for one reason and one reason only, to save money. Saving money what a wonderful oxymoronic term for anyone who is near the brink of financial flux. Saving some cash means having some cash to save? Who has cash now days? Pimps, the under pit of society, pushers, dope sellers, underground narcotic agents filled with bankrolls provided by NCIS coffers that are overflowing with greenbacks? Maybe. How about those that are employed, have a job, didn’t loose a job, or simple have several jobs or for one reason or another have been frugal with the money they did earn. Those folks are the ones that have some cash to save, not me. Its not that I have been wasteful by my standards, but by some who maybe have not experienced life’s challenges as myself, it may seem to them that I have frittered away at the boundaries between financial prudence and spend thriftiness.
In the interest in the of financial prudence I moved into a rental situation where I share a house with two to three other individuals. We all have common area’s such as the kitchen two bathrooms, living room, laundry, and of course the kitchen. The pantry has wire shelves, one per tenant. My stuff never mingles with anyone else’s, and the same is true with the freezer and fridge spaces. Everyone has a place, and for the most part everyone keeps to that space. That’s the theory anyway. Notable exceptions are the occasional milk thief, bread user, coffee drinker, butter dabbler or in very rare instances the guest dishwasher facilitator, as I will call them here. Occasionally, rarely, indeed almost as rare as the celestial phenomenon known as the “blue moon,” this honorary self designee succumbs to the glories and task driven problems of filling the dishwasher and actually plopping a soap pillow in, starting it up, and in somewhat rarer fashion, puts away its gleaming contents back on the shelf where they belong. Saint’s preserve us!
It is almost the exclusive task of the “dishwasher monger,” to do the cleaning rounds and make sure the roving and proliferating insect population does not run rampant in the guacamole, coffee maker, or the forest of crumbs that sometime accompany men who share a house. Those tasks seemingly I have owned since arrival last April.
With that being said, and given the fact that the house is nearly freshly painted, in a good neighborhood, and is less then 6 years old, it seems a small price to pay for such luxurious accommodations.
However, there is always an adjustment when an old roommate leaves and new roommate arrives. Other then cleaning, tiding, moving furniture, and scraping the soap scum off the tub surface, which here to for have enjoyed being hermetically protected from beating shower water by a thick protective coat of yellow dial soap to the thickness of the hide of the North American Sturgeon. I swear that I watched the miniature Mississippi delta drain into the gulf for months until cleaning occurred not by the creator, but by an innocent out of work high school science teacher that almost never needed to apply soap to his feet because there was always a ready supply already available down below the waterline. The deltaic deposits returned and were removed by hurricane Karen in 2009, just prior to the new influx of roommates that are in the process of moving in.
Now here is the kicker.
After all is said and done and the smoke clears, the soap scum drainage basin has been removed, all that is left to evidence that others have come before are the left over pickle jars in the fridge. Half full, some out of date more then two years, and condiments that may have been edible during the last presidential administration, that now mimic edibility by a kitschy label that I can’t bring myself to open and sniff. Maybe I need to swallow my re-cycling pride and open the trash and just chuck out hanger ons, not recycle.
Don’t tell the Sierra Club.
Friday, January 15, 2010
The onset of freedom
Strickland Calhoun sat quietly in the dentist chair waiting for the blue coat to come back and require an “open wide”. Suddenly nothing happened the way it seemed to have in the past. The blue coat didn’t return. The music that normally played from the white speaker adjacent to the large glaring light was not working. Something was discordant and this upset him gravely. He didn’t like to be out of his comfort zone. It disturbed him. It made the hair stand up on the nape of his neck, and soon cold sweats were to follow. He was sure of it, and didn’t like it. The digital clock on the wall that displayed Atomic time was flashing a warning signal and a gray indicator square indicated that it has lost signal. Nervously he checked his watch, then his cell phone, then the wall clock. Nothing. No change. He puzzled, coughed and cleared his throat and looked around as if to inquire to some unseen attendant as to the location of the nearest restroom. Seeing no one, hearing no music, having no sense of time to relate all these non-changes, he began to hum the national anthem. The blue coat returned, the signal LED flashed on the wall clock, and Nora Jones crooned from the white speaker. All was right with the world. The drill began and stopped. A co-pay and reschedule was given and recorded at the receptionist. A smile, a complimentary sugarfree throat lozenge, and a second glance at the receptionist as the door closed behind him.
Key, ignition, pay attendant, highway, music on, cell phone calls, then exit 19, then home. Nothing interestingly different except for the novocain and the sound of a diet coke can rolling mindlessly back and forth on the passenger side floor mat. Rattle… rattle.. crash…. Rattle..crash. “I must remember to throw that out,” he thought as the car found the driveway, parked itself. Placing hand to cheek, he could feel the tingly pain build indicating that soon he will feel again.
Key, ignition, pay attendant, highway, music on, cell phone calls, then exit 19, then home. Nothing interestingly different except for the novocain and the sound of a diet coke can rolling mindlessly back and forth on the passenger side floor mat. Rattle… rattle.. crash…. Rattle..crash. “I must remember to throw that out,” he thought as the car found the driveway, parked itself. Placing hand to cheek, he could feel the tingly pain build indicating that soon he will feel again.
Wednesday, December 30, 2009
Monday, December 21, 2009
Changed plans
I am reminded each time when well-laid plans are changed, that most things in life are not guaranteed. Indeed if anything can be said about planning, it is that plans are usually, changed to accommodate the whims of fate. That’s not bad on the whole, just the way it is. A wise person once said, “Life happens when you’re not expecting it.” How true that is on many occasions in recent memory. Often plans for travel, visiting friends, or vacations have been dashed due to extenuating circumstances beyond control. I am sure that some friends of mine who hear from me that “ I will come to visit,” year after visit-less year, have grown tired of waiting for me and dismiss the annual proclamation as so many politicians promises for reform when they are trying to garner the plebiscite.
Tuesday, December 15, 2009
Polar bears, Whales, and puppy dog tails
Here is a cold hard fact. Winter happens, Climate change is happening every century, every decade, every year. We have weather every day. The distinction between climate change and in our weather should be distinct but are not portrayed in the media as being separate, and it is for that reason I believe that folks get the two confused.
How often have you heard folks talk about “Global Warming” in the context of current weather conditions:
“It’s so hot, it must be global warming.”
“Our planet can’t be going into an ice age; my garden has dried up due to lack of rain.”
“How come it’s so cold here, I thought global warming was going to keep us warmer?”
I can’t tell you how frustrating it is as an educator to hear miss-information bandied about like it’s the gospel truth. Take the childhood game of telling secrets where one child is given a phrase to say to their neighbor and then ask the neighbor to pass it on. By the time it reaches the third child it has changed slightly. By the time it reaches the end of the line, it may not resemble in any way what the first child heard. Why is that? I think that everyone knows why that is. Simply put, folks forget, fill in and embellish what they don’t know to sound important or in most cases not to sound dumb. Really, it’s because we are bad at recording data verbally and keeping our facts strait.
Another example is when someone witnesses a crash and has to be debriefed by a police officer. The sooner the officer gets to the witness the more accurate the account. After a while, emotions, personal thoughts, bias, and internalized hidden agenda’s tend to convolute the original experience to fit that person’s “world view,” of what just took place.
Enter Global climatic shifts and weather….
Yes climate change is happening.
Yes our weather on a daily basis has some patterns, those patterns over time we call climate. If our weather changes over time then climate changes over time. However, if we look at small data sets like in all science, our conclusion is not accurate what so ever.
There is a body of evidence showing that recent events (last 100 years) that our climate has been changing from a colder mean temperature (average temperature) to a slightly warmer one. A key point that is missed when the global climatic shift, which is natural, normal and cyclical, is that data, even from some of the oldest dendrochronological studies (The systematic study of tree rings showing yearly weather change, growing season, drought, rain and so on) fails to give a complete picture. Any 9th grader can tell you that the evidence is clear, global warming is happening and that we are the cause of it. I know because I have had 13-14 year old students come into my classroom with gross miss information about the science behind what they espouse to be completely accurate. This worldview is carried on into college with my fellow students. The key understanding global climate change is to not look at it as an emotional issue supercharged with polar bears, whales, and the loss of panda habitat. I will be very sad to see those gene sets parish. But to focus on the changes that are taking place on a biological, ecological, meteorological, and planetary geological level and interpret those findings as a change in the NATURE of the planet. Our focus has been for decades now on how our lives as humans are wrecking havoc on the planet and that we should be removed. Folks, if we are removed we can’t enjoy living on the planet.
I believe we are an integral connected species with mother Earth, not a pustule that needs to be cut and drained before it becomes infected. The very notion that we are parasitically drawing the lifeblood from the planet is a pervasive and popular view, which in many cases is hard to discredit given the global changes in forestland, desertification, and species extinction due to over use, over harvest and down right negligence by humans. I think that we should cooperate with nature, feel that we are part of the natural world, and teach stewardship, conservation, land use, and ultimately responsibility towards our species and our future as a collective organism known as the earth’s biomass.
Just my thoughts…
What are yours?
How often have you heard folks talk about “Global Warming” in the context of current weather conditions:
“It’s so hot, it must be global warming.”
“Our planet can’t be going into an ice age; my garden has dried up due to lack of rain.”
“How come it’s so cold here, I thought global warming was going to keep us warmer?”
I can’t tell you how frustrating it is as an educator to hear miss-information bandied about like it’s the gospel truth. Take the childhood game of telling secrets where one child is given a phrase to say to their neighbor and then ask the neighbor to pass it on. By the time it reaches the third child it has changed slightly. By the time it reaches the end of the line, it may not resemble in any way what the first child heard. Why is that? I think that everyone knows why that is. Simply put, folks forget, fill in and embellish what they don’t know to sound important or in most cases not to sound dumb. Really, it’s because we are bad at recording data verbally and keeping our facts strait.
Another example is when someone witnesses a crash and has to be debriefed by a police officer. The sooner the officer gets to the witness the more accurate the account. After a while, emotions, personal thoughts, bias, and internalized hidden agenda’s tend to convolute the original experience to fit that person’s “world view,” of what just took place.
Enter Global climatic shifts and weather….
Yes climate change is happening.
Yes our weather on a daily basis has some patterns, those patterns over time we call climate. If our weather changes over time then climate changes over time. However, if we look at small data sets like in all science, our conclusion is not accurate what so ever.
There is a body of evidence showing that recent events (last 100 years) that our climate has been changing from a colder mean temperature (average temperature) to a slightly warmer one. A key point that is missed when the global climatic shift, which is natural, normal and cyclical, is that data, even from some of the oldest dendrochronological studies (The systematic study of tree rings showing yearly weather change, growing season, drought, rain and so on) fails to give a complete picture. Any 9th grader can tell you that the evidence is clear, global warming is happening and that we are the cause of it. I know because I have had 13-14 year old students come into my classroom with gross miss information about the science behind what they espouse to be completely accurate. This worldview is carried on into college with my fellow students. The key understanding global climate change is to not look at it as an emotional issue supercharged with polar bears, whales, and the loss of panda habitat. I will be very sad to see those gene sets parish. But to focus on the changes that are taking place on a biological, ecological, meteorological, and planetary geological level and interpret those findings as a change in the NATURE of the planet. Our focus has been for decades now on how our lives as humans are wrecking havoc on the planet and that we should be removed. Folks, if we are removed we can’t enjoy living on the planet.
I believe we are an integral connected species with mother Earth, not a pustule that needs to be cut and drained before it becomes infected. The very notion that we are parasitically drawing the lifeblood from the planet is a pervasive and popular view, which in many cases is hard to discredit given the global changes in forestland, desertification, and species extinction due to over use, over harvest and down right negligence by humans. I think that we should cooperate with nature, feel that we are part of the natural world, and teach stewardship, conservation, land use, and ultimately responsibility towards our species and our future as a collective organism known as the earth’s biomass.
Just my thoughts…
What are yours?
Past Climate Change
Past Climate Change
Related Links
U.S. Global Change Research Program
USGCP: Product 3.4 - Abrupt Climate Change
NASA: Paleoclimatology Site
NOAA
• Climate Timeline
• Paleoclimatology Program
• Abrupt Climate Change Web site
Causes of Change | Rates of change | The Last 2,000 Years
The Earth's climate has changed throughout history. From glacial periods (or "ice ages") where ice covered significant portions of the Earth to interglacial periods where ice retreated to the poles or melted entirely - the climate has continuously changed.
Scientists have been able to piece together a picture of the Earth's climate dating back decades to millions of years ago by analyzing a number of surrogate, or "proxy," measures of climate such as ice cores, boreholes, tree rings, glacier lengths, pollen remains, and ocean sediments, and by studying changes in the Earth's orbit around the sun.
This page contains information about the causes of climate change throughout the Earth's history, the rates at which the climate has changed, as well as information about climate change during the last 2,000 years.
Causes of Change Prior to the Industrial Era (pre-1780)
Known causes, “drivers” or “forcings” of past climate change include:
• Changes in the Earth's orbit: Changes in the shape of the Earth's orbit (or eccentricity) as well as the Earth's tilt and precession affect the amount of sunlight received on the Earth's surface. These orbital processes -- which function in cycles of 100,000 (eccentricity), 41,000 (tilt), and 19,000 to 23,000 (precession) years -- are thought to be the most significant drivers of ice ages according to the theory of Mulitin Milankovitch, a Serbian mathematician (1879-1958). The National Aeronautics and Space Administration's (NASA) Earth Observatory offers additional information about orbital variations and the Milankovitch Theory.
• Changes in the sun's intensity: Changes occurring within (or inside) the sun can affect the intensity of the sunlight that reaches the Earth's surface. The intensity of the sunlight can cause either warming (for stronger solar intensity) or cooling (for weaker solar intensity). According to NASA research, reduced solar activity from the 1400s to the 1700s was likely a key factor in the “Little Ice Age” which resulted in a slight cooling of North America, Europe and probably other areas around the globe. (See additional discussion under The Last 2,000 Years.)
• Volcanic eruptions: Volcanoes can affect the climate because they can emit aerosols and carbon dioxide into the atmosphere.
o Aerosol emissions: Volcanic aerosols tend to block sunlight and contribute to short term cooling. Aerosols do not produce long-term change because they leave the atmosphere not long after they are emitted. According to the United States Geological Survey (USGS), the eruption of the Tambora Volcano in Indonesia in 1815 lowered global temperatures by as much as 5ºF and historical accounts in New England describe 1816 as “the year without a summer.”
o Carbon dioxide emissions: Volcanoes also emit carbon dioxide (CO2), a greenhouse gas, which has a warming effect. For about two-thirds of the last 400 million years, geologic evidence suggests CO2 levels and temperatures were considerably higher than present. One theory is that volcanic eruptions from rapid sea floor spreading elevated CO2 concentrations, enhancing the greenhouse effect and raising temperatures. However, the evidence for this theory is not conclusive and there are alternative explanations for historic CO2 levels (NRC, 2005). While volcanoes may have raised pre-historic CO2 levels and temperatures, according to the USGS Volcano Hazards Program, human activities now emit 150 times as much CO2 as volcanoes (whose emissions are relatively modest compared to some earlier times).
These climate change “drivers” often trigger additional changes or “feedbacks” within the climate system that can amplify or dampen the climate's initial response to them (whether the response is warming or cooling). For example:
• Changes in greenhouse gas concentrations: The heating or cooling of the Earth's surface can cause changes in greenhouse gas concentrations. For example, when global temperatures become warmer, carbon dioxide is released from the oceans. When changes in the Earth's orbit trigger a warm (or interglacial) period, increasing concentrations of carbon dioxide may amplify the warming by enhancing the greenhouse effect. When temperatures become cooler, CO2 enters the ocean and contributes to additional cooling. During at least the last 650,000 years, CO2 levels have tended to track the glacial cycles (IPCC, 2007). That is, during warm interglacial periods, CO2 levels have been high and during cool glacial periods, CO2 levels have been low (see Figure 1).
Figure 1: Fluctuations in temperature (red line) and in the atmospheric concentration of carbon dioxide (yellow) over the past 649,000 years. The vertical red bar at the end is the increase in atmospheric carbon dioxide levels over the past two centuries and before 2007. Click on thumbnail for a full-size image and references.
• Changes in ocean currents: The heating or cooling of the Earth's surface can cause changes in ocean currents. Because ocean currents play a significant role in distributing heat around the Earth, changes in these currents can bring about significant changes in climate from region to region.
Top of page
Rates of Change
Studies of the Earth's previous climate suggest periods of stability as well as periods of rapid change. Recent climate research suggests:
• Interglacial climates (such as the present) tend to be more stable than cooler, glacial climates. For example, the climate during the current and previous interglacials (known as the Holocene and Eemian interglacials) has been more stable than the most recent glacial period (known as the Last Glacial Maximum). This glacial period was characterized by a long string of widespread, large and abrupt climate changes (NRC, 2002).
• Abrupt or rapid climate changes tend to frequently accompany transitions between glacial and interglacial periods (and vice versa). For example, a significant part of the Northern Hemisphere (particularly around Greenland) may have experienced warming rates of 14-28ºF over several decades during and after the most recent ice age (IPCC, 2007).
While abrupt climate changes have occurred throughout the Earth's history, human civilization arose during a period of relative climate stability.
Top of page
The Last 2,000 Years
During the last 2,000 years, the climate has been relatively stable. Scientists have identified three departures from this stability, known as the Medieval Climate Anomaly (also referred to as the Medieval Warm Period), the Little Ice Age and the Industrial Era:
• The Medieval Climate Anomaly: Between roughly 900 and 1300 AD, evidence suggests Europe, Greenland and Asia experienced relative warmth. While historical accounts and other evidence document the warmth that occurred in some regions, the geographical extent, magnitude and timing of the warmth during this period is uncertain (NRC, 2006). The American West experienced very dry conditions around this time.
• The Little Ice Age: A wide variety of evidence supports the global existence of a "Little Ice Age" (this was not a true "ice age" since major ice sheets did not develop) between about 1500 and 1850 (NRC, 2006). Average temperatures were possibly up to 2ºF colder than today, but varied by region.
• The Industrial Era: An additional warm period has emerged in the last 100 years, coinciding with substantially increasing emissions of greenhouse gases from human activities (see Recent Climate Change for more information).
Prior to the Industrial Era, the Medieval Climate Anomaly and Little Ice Age had defined the upper and lower boundaries of the climate's recent natural variability and are a reflection of changes in climate drivers (the sun's variability and volcanic activity) and the climate's internal variability (referring to random changes in the circulation of the atmosphere and oceans).
The issue of whether the temperature rise of last 100 years crossed over the warm limit of the boundary defined by the Medieval Climate Anomaly has been a controversial topic in the science community. The National Academy of Sciences recently completed a study to assess the efforts to reconstruct temperatures of the past one to two millennia (see Figure 2) and place the Earth's current warming in historical context (NRC, 2006).
Figure 2: Reconstructions of (Northern Hemisphere average or global average) surface temperature variations from six research teams (in different color shades) along with the instrumental record of global average surface temperature (in black). Each curve illustrates a somewhat different history of temperature changes, with a range of uncertainties that tend to increase backward in time (as indicated by the shading). Reference: NRC, 2006. (Figure reprinted with permission from Surface Temperature Reconstructions© (2006) by the National Academy of Sciences, Courtesy of the National Academies Press , Washington, D.C.)
According to the study (NRC, 2006):
• There is a high level of confidence that the global average temperature during the last few decades was warmer than any comparable period during the last 400 years.
• Present evidence suggests that temperatures at many, but not all, individual locations were higher during the past 25 years than any period of comparable length since A.D. 900. However, uncertainties associated with this statement increase substantially backward in time.
• Very little confidence can be assigned to estimates of hemisphere average or global average temperature prior to A.D. 900 due to limited data coverage and challenges in analyzing older data.
Top of page
References
• IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning (eds.)].
• National Research Council (NRC), 2002: Abrupt Climate Change, Inevitable Surprises. National Academy Press, Washington, DC. National Academy Press, Washington, DC
• National Research Council (NRC), 2005: Radiative Forcing of Climate Change. National Academy Press, Washington, DC. National Academy Press, Washington, DC
• National Research Council (NRC), 2006. Surface Temperature Reconstructions For the Last 2,000 Years. National Academy Press, Washington, DC.
Related Links
U.S. Global Change Research Program
USGCP: Product 3.4 - Abrupt Climate Change
NASA: Paleoclimatology Site
NOAA
• Climate Timeline
• Paleoclimatology Program
• Abrupt Climate Change Web site
Causes of Change | Rates of change | The Last 2,000 Years
The Earth's climate has changed throughout history. From glacial periods (or "ice ages") where ice covered significant portions of the Earth to interglacial periods where ice retreated to the poles or melted entirely - the climate has continuously changed.
Scientists have been able to piece together a picture of the Earth's climate dating back decades to millions of years ago by analyzing a number of surrogate, or "proxy," measures of climate such as ice cores, boreholes, tree rings, glacier lengths, pollen remains, and ocean sediments, and by studying changes in the Earth's orbit around the sun.
This page contains information about the causes of climate change throughout the Earth's history, the rates at which the climate has changed, as well as information about climate change during the last 2,000 years.
Causes of Change Prior to the Industrial Era (pre-1780)
Known causes, “drivers” or “forcings” of past climate change include:
• Changes in the Earth's orbit: Changes in the shape of the Earth's orbit (or eccentricity) as well as the Earth's tilt and precession affect the amount of sunlight received on the Earth's surface. These orbital processes -- which function in cycles of 100,000 (eccentricity), 41,000 (tilt), and 19,000 to 23,000 (precession) years -- are thought to be the most significant drivers of ice ages according to the theory of Mulitin Milankovitch, a Serbian mathematician (1879-1958). The National Aeronautics and Space Administration's (NASA) Earth Observatory offers additional information about orbital variations and the Milankovitch Theory.
• Changes in the sun's intensity: Changes occurring within (or inside) the sun can affect the intensity of the sunlight that reaches the Earth's surface. The intensity of the sunlight can cause either warming (for stronger solar intensity) or cooling (for weaker solar intensity). According to NASA research, reduced solar activity from the 1400s to the 1700s was likely a key factor in the “Little Ice Age” which resulted in a slight cooling of North America, Europe and probably other areas around the globe. (See additional discussion under The Last 2,000 Years.)
• Volcanic eruptions: Volcanoes can affect the climate because they can emit aerosols and carbon dioxide into the atmosphere.
o Aerosol emissions: Volcanic aerosols tend to block sunlight and contribute to short term cooling. Aerosols do not produce long-term change because they leave the atmosphere not long after they are emitted. According to the United States Geological Survey (USGS), the eruption of the Tambora Volcano in Indonesia in 1815 lowered global temperatures by as much as 5ºF and historical accounts in New England describe 1816 as “the year without a summer.”
o Carbon dioxide emissions: Volcanoes also emit carbon dioxide (CO2), a greenhouse gas, which has a warming effect. For about two-thirds of the last 400 million years, geologic evidence suggests CO2 levels and temperatures were considerably higher than present. One theory is that volcanic eruptions from rapid sea floor spreading elevated CO2 concentrations, enhancing the greenhouse effect and raising temperatures. However, the evidence for this theory is not conclusive and there are alternative explanations for historic CO2 levels (NRC, 2005). While volcanoes may have raised pre-historic CO2 levels and temperatures, according to the USGS Volcano Hazards Program, human activities now emit 150 times as much CO2 as volcanoes (whose emissions are relatively modest compared to some earlier times).
These climate change “drivers” often trigger additional changes or “feedbacks” within the climate system that can amplify or dampen the climate's initial response to them (whether the response is warming or cooling). For example:
• Changes in greenhouse gas concentrations: The heating or cooling of the Earth's surface can cause changes in greenhouse gas concentrations. For example, when global temperatures become warmer, carbon dioxide is released from the oceans. When changes in the Earth's orbit trigger a warm (or interglacial) period, increasing concentrations of carbon dioxide may amplify the warming by enhancing the greenhouse effect. When temperatures become cooler, CO2 enters the ocean and contributes to additional cooling. During at least the last 650,000 years, CO2 levels have tended to track the glacial cycles (IPCC, 2007). That is, during warm interglacial periods, CO2 levels have been high and during cool glacial periods, CO2 levels have been low (see Figure 1).
Figure 1: Fluctuations in temperature (red line) and in the atmospheric concentration of carbon dioxide (yellow) over the past 649,000 years. The vertical red bar at the end is the increase in atmospheric carbon dioxide levels over the past two centuries and before 2007. Click on thumbnail for a full-size image and references.
• Changes in ocean currents: The heating or cooling of the Earth's surface can cause changes in ocean currents. Because ocean currents play a significant role in distributing heat around the Earth, changes in these currents can bring about significant changes in climate from region to region.
Top of page
Rates of Change
Studies of the Earth's previous climate suggest periods of stability as well as periods of rapid change. Recent climate research suggests:
• Interglacial climates (such as the present) tend to be more stable than cooler, glacial climates. For example, the climate during the current and previous interglacials (known as the Holocene and Eemian interglacials) has been more stable than the most recent glacial period (known as the Last Glacial Maximum). This glacial period was characterized by a long string of widespread, large and abrupt climate changes (NRC, 2002).
• Abrupt or rapid climate changes tend to frequently accompany transitions between glacial and interglacial periods (and vice versa). For example, a significant part of the Northern Hemisphere (particularly around Greenland) may have experienced warming rates of 14-28ºF over several decades during and after the most recent ice age (IPCC, 2007).
While abrupt climate changes have occurred throughout the Earth's history, human civilization arose during a period of relative climate stability.
Top of page
The Last 2,000 Years
During the last 2,000 years, the climate has been relatively stable. Scientists have identified three departures from this stability, known as the Medieval Climate Anomaly (also referred to as the Medieval Warm Period), the Little Ice Age and the Industrial Era:
• The Medieval Climate Anomaly: Between roughly 900 and 1300 AD, evidence suggests Europe, Greenland and Asia experienced relative warmth. While historical accounts and other evidence document the warmth that occurred in some regions, the geographical extent, magnitude and timing of the warmth during this period is uncertain (NRC, 2006). The American West experienced very dry conditions around this time.
• The Little Ice Age: A wide variety of evidence supports the global existence of a "Little Ice Age" (this was not a true "ice age" since major ice sheets did not develop) between about 1500 and 1850 (NRC, 2006). Average temperatures were possibly up to 2ºF colder than today, but varied by region.
• The Industrial Era: An additional warm period has emerged in the last 100 years, coinciding with substantially increasing emissions of greenhouse gases from human activities (see Recent Climate Change for more information).
Prior to the Industrial Era, the Medieval Climate Anomaly and Little Ice Age had defined the upper and lower boundaries of the climate's recent natural variability and are a reflection of changes in climate drivers (the sun's variability and volcanic activity) and the climate's internal variability (referring to random changes in the circulation of the atmosphere and oceans).
The issue of whether the temperature rise of last 100 years crossed over the warm limit of the boundary defined by the Medieval Climate Anomaly has been a controversial topic in the science community. The National Academy of Sciences recently completed a study to assess the efforts to reconstruct temperatures of the past one to two millennia (see Figure 2) and place the Earth's current warming in historical context (NRC, 2006).
Figure 2: Reconstructions of (Northern Hemisphere average or global average) surface temperature variations from six research teams (in different color shades) along with the instrumental record of global average surface temperature (in black). Each curve illustrates a somewhat different history of temperature changes, with a range of uncertainties that tend to increase backward in time (as indicated by the shading). Reference: NRC, 2006. (Figure reprinted with permission from Surface Temperature Reconstructions© (2006) by the National Academy of Sciences, Courtesy of the National Academies Press , Washington, D.C.)
According to the study (NRC, 2006):
• There is a high level of confidence that the global average temperature during the last few decades was warmer than any comparable period during the last 400 years.
• Present evidence suggests that temperatures at many, but not all, individual locations were higher during the past 25 years than any period of comparable length since A.D. 900. However, uncertainties associated with this statement increase substantially backward in time.
• Very little confidence can be assigned to estimates of hemisphere average or global average temperature prior to A.D. 900 due to limited data coverage and challenges in analyzing older data.
Top of page
References
• IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning (eds.)].
• National Research Council (NRC), 2002: Abrupt Climate Change, Inevitable Surprises. National Academy Press, Washington, DC. National Academy Press, Washington, DC
• National Research Council (NRC), 2005: Radiative Forcing of Climate Change. National Academy Press, Washington, DC. National Academy Press, Washington, DC
• National Research Council (NRC), 2006. Surface Temperature Reconstructions For the Last 2,000 Years. National Academy Press, Washington, DC.
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Saturday, December 12, 2009
FISHPHONE
If only eating green were as simple as going to a farmers market, and picking out some organically produced foods, and using that re-usable shopping tote (I have 6) at the grocery store. Something that most folks never think about up until recently is eating locally. It isn’t always possible to do this, especially in the colder months. The fish for example that we eat should be as local as you can get. Granted not everyone will like to eat smelt (pronounced Shmelt) in the dead of Winter, but I like them. Pan friend with salt and pepper and a little corn meal. Oh my mouth is watering now.
Try this handy and fun way of deciding on what fish to buy:
When you’re at the fish counter trying to decide what to buy for dinner, use your cell phone to text seafood conservation group Blue Ocean Institute’s Fishphone sevice. Text 30644 and enter FISH, followed by the name of the fish you want to buy. You’ll receive a text telling you if the variety is good for you and the world.
Try this handy and fun way of deciding on what fish to buy:
When you’re at the fish counter trying to decide what to buy for dinner, use your cell phone to text seafood conservation group Blue Ocean Institute’s Fishphone sevice. Text 30644 and enter FISH, followed by the name of the fish you want to buy. You’ll receive a text telling you if the variety is good for you and the world.
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