Global Climate Change in History

Medieval Global Temperature Optimum

          The Medieval Global Temperature Optimum is also referred to as the Medieval Warm Period, Medieval Climate Optimum, or Medieval Climatic Anomaly. It was a period of warm climate in the North Atlantic that may have been influenced by several other events happening around the world. This period of higher temperatures lasted from AD 950 to 1250, during the European Middle Ages.

          There has been question as to if the Medieval Global Temperature Optimum was actually a global. While Hubert Lamb initially published research in 1965 showing a notably warm climate in many parts of the world, the IPCC Third Assessment Report in 2001 stated that current evidence did not support global synchronous periods of warmth over that time period. Possible causes of this increase of warmth have been higher solar radiation levels than previously recorded and less volcanic activity, and changes in the circulation patterns in the ocean, which bring warm seawater into the North Atlantic. Reconstructions of past weather trends are often region-specific rather than classified globally.

Little Ice Age

          The Little Ice Age was a period of time that was cooler than previous recorded temperatures, occurring after the Medieval Global Temperature Optimum. Even though it was not a true ice age, it was considered a long period of colder climate. This cool period lasted from the sixteenth century through the nineteenth, roughly 1350 to 1850, while dates vary slightly depending on the source.

          Francois E. Matthes coined the term of the Little Ice Age in 1939. There have been several proposals for the cause of this cooled period on earth, ranging from cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, an inherent variability in global climate, to decreases in the human population. Pack ice started advancing south in the North Atlantic and glaciers showed the same trends in Greenland during the thirteenth century. Radiocarbon dating of dead plant roots from beneath ice caps was done, showing that ice growth and cold summers began suddenly between AD 1275 and 1300 resulting from Atlantic pack ice beginning to grow in 1250. Other notable dates that stemmed from the climate change included undependable summer temperatures in Northern Europe in 1300, increased rainfall and the Great Famine in 1315, an intensification of cold climate starting between 1430 and 1455, worldwide glacial expansion theorized to have started in 1550, and the first climactic minimum recorded in 1650.

          In the thirteenth century Evidence of the Little Ice Age shows an increased number of mountain glaciers across Alaska, New Zealand, and Patagonia, although they appear to have occurred at different periods of time. This research goes back to support the idea that the heating and cooling of the earth is not universally global but dependent on the region during a period of time.

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

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

http://www.skepticalscience.com/medieval-warm-period.htm 

Air Quality in Bogota, Colombia

          Air Quality in Bogota, Colombia

            Bogota, Colombia is ranked at 153 on the air quality map, resulting in unhealthy conditions. There are over 8.5 million people living in the busy capital of Bogota, driving over 1.4 million vehicles on the road every day. In December of 2013, 1,447,335 private vehicles were registered in the city, with a 76% increase in only seven years. This is not even taking into account government owned vehicles, public transportation, or shipping trucks. The massive amount of vehicles traveling in this urban area means more emissions. Road traffic in Bogota is responsible for over 90% or emissions, resulting in large quantities of air pollution. This type of pollution causes respiratory diseases which are the main cause of child death and infant mortality in Bogota, with about 600,000 children under the age of five treated each year and more than 6000 premature deaths each year in Colombia as a whole. Some of these respiratory diseases include asthma, bronchitis, COPD, cystic fibrosis, and emphysema.

         



          Many of these conditions stem from the five main pollutants of automobiles, including carbon monoxide, nitrogen oxides, sulfur dioxide, particulate matter, and volatile organic compounds. The dangerously high concentrations of particulate matter is a major health concern for the people in the capital. Several of those five main pollutants are also results of industrial sources in Bogota, where 4700 industries are located. These industries use coal, fuel oil, diesel, and natural gas in heaters in boilers and the majority of them do not have emission control devices or programs to reduce and prevent air pollution.



         



        While the capital Bogota is one of the most air polluted cities in all of Latin America, there has been little government involvement solving some of the prevalent issues. Little has been done to improve the quality of diesel fuel in Bogota, which currently contains higher sulfur levels than other major cities. Emission from public bus transit is responsible for 90% of the particulate matter from vehicles. In a recent transportation strike, the concentration of particulate matter in the city dropped 54% from the previous week just from the reduction of vehicles on the road. This source should be a red flag for government authorities to make changes to transportation systems in order to regulate air pollution. Despite small interventions such as car-free day the first Thursday of February and "Pico y Placa" which restricts certain cars from driving on designated days according to their license plate number, the smog and air pollution is clearly evident in the city. The population of Bogota is currently awaiting solutions for air pollution through more public transportation and new policies, which are said to get started in 2015 and be more prevalent by 2018. With the capitols air quality continuously deteriorating, it is essential for policies to be put in place and interventions to be established immediately by both local government and Colombian officials.

http://infoscience.epfl.ch/record/166732/files/PDM_FinalReport_JPR.pdf

http://americasquarterly.org/content/gasping-solution-bogota-air-pollution-problem

http://www.drgdiaz.com/air_pollution_bogota.shtml

http://www.ing.unal.edu.co/grupos/calidad_aire/doc/eventos/0058airqualityinbogota.pdf

Gold Mining

Gold Mining

                While it is impossible to predict the exact time period that humans began to mine for gold, research shows that it could be at least 7000 years old. Gaining access to these gold resources were more difficult long ago, before the tools and machines used today were invented.  Today approximately 2,500 metric tons of gold is mined and produced per year. With the price of gold ranging around $256, all of the gold produced in a year is worth about $12,805,000,000. India consumes the most gold out of all countries with 745.7 metric tons, followed by China with 428 tons, and the United States with 128.61 tons. That’s a lot of gold!!

--Interesting gold facts: http://www.numbersleuth.org/worlds-gold/ --

There are several methods and processes that miners go through to collect gold today.

                The first method is placer mining in which the use of water or dredging is most often required. Gold accumulates in placer deposits that are composed of loose material. This material makes it difficult to tunnel through the earth, making the use of water for extracting the gold most productive.

                Another method for separating gold is an old fashion manual technique, panning. Most often used in river beds or streams, pans are filled with mineral deposits, submerged in water, shaken to separate materials, and sorted. The density of gold is much higher than other minerals causing the gold deposits to settle at the bottom of the pan. This method is the quickest and easiest but not the most efficient for extracting large amounts of gold.

                Sluicing is a method used for small-scale extraction of gold. A sluice box is a man made channel with riffles set in the bottom, creating dead zones in the current. This allows less dense materials to flow through and out of the box while the more dense gold deposits in the current drop out of the channel and settle behind the riffles.

                Small-scale miners often use a method called dredging. Suction dredges are operated by one or two people and float on the water. These machines consist of a sluice box supported by pontoons and a suction hose that is attached. One of the miners works beneath the water with the suction hose to collect gold deposits.

                Large gold mines produce materials that are left over after the separation process. These things are called tailings, also known as mine dumps, slimes, or leach residue. These tailings are harmful to the environment and introduce products that were not initially exposed.  The disposal of these tailings is an important part of the mining process, as well as creating a sustainable practice for the environment. In the past, these tailings have been disposed as conveniently as possible, usually being dumped into a river or stream of water. Sadly that method still exists with gold mines in less developed nations that do not have as strict rules or regulations.

                

              

The largest gold mine in the world is the Grasberg Mine, located in Indonesia in the province of Papua. 

The first traces of gold were found in 1936 by Dutch geologist Jean Jacques Dozy and the gold mine today has over 19,500 employees working there. This particular mine produces 230,000 tons of tailings per day, creating a large concern for damage to the surrounding environment. These tailings wash into the nearby river system that feeds into the Arafura Sea, causing large amounts of sediment and native fish populations to disappear.

 

http://www.bbc.com/news/magazine-21969100

http://money.howstuffworks.com/question213.htm

http://www.australian-gold.com/australian-gold-mining-production.html

Traffic Study: Mercer Village

Traffic Study

Objective: The goal is to research and analyze the traffic patterns on the Mercer Campus and how these trends can relate to conservation and sustainability in the environment.

Methods: My personal research was done Monday in Mercer Village from 9:30am-10:30am. I watched and recorded the number of vehicles that passed by, their size, and how many passengers were in each vehicle.

Results:

Small Cars -120/ Large Cars- 141

Small: 1 Passenger: (96)         2 Passengers: (24)

Large: 1 Passenger: (108)       2 Passengers: (33)

Bus/Van: (9)

Taxi: (6)

           During the hour of traffic in Mercer Village from 9:30am to 10:30am, there were on average, 141 large vehicles and 120 small vehicles passing through. These large vehicles included SUV’s, smaller SUV’s, trucks, and vans. Out of these large vehicles, 33 of them had two passengers including the driver, while 108 of them had only the driver in the vehicle. Out of the smaller cars, 24 of them had two passengers while 96 had only the driver. No vehicles passed by during this hour that had more than 2 passengers, besides transportation vehicles. A bus or large passenger van drove by a total of nine times. Six taxis drove by, three of which had additional passengers to the driver and three that did not.

Conclusion:

            I think these statistics say something about a large amount of the Mercer/Macon community. It is hard to be conscious of the environment when so more people are driving large vehicles than smaller, fuel efficient cares. In addition to the size of the vehicle, it is important to pay attention to how many people are utilizing each vehicle that is on the road. So few people are carpooling, which means that each person is driving their own vehicle and ultimately contributing to gas emission in the environment. The more people that drive smaller, fuel-efficient vehicles as well as carpool with others, are helping to reduce oil demand and air pollution.

           These assumptions about Macon as a whole can vary slightly, considering on a college campus, many people drive to school or in between classes alone. Statistics for vehicle size or passenger number could change if we watched traffic out on Eisenhower rather than in Mercer Village. To find an accurate calculation of these numbers in Macon, you would have to tally up the amount of small vs large vehicles per household. The number of licensed drivers per household is also an important number to have. If a large family of six has only one vehicle, then you know that they must be carpooling. If that same family had a separate car for the mother, father, and two oldest children, it is much less friendly for the environment.