The most convincing evidence to support the already clear dramatic increase in greenhouse gases and global temperature in the last two centuries involves the Suess Effect. Fossil fuels are formed by the ancient decomposition of organic matter, which is predominantly from vegetation. Elemental carbon, 12C has two persisting radioactive isomers, 13C and 14C, which decay at known constant rates. In modern day plant metabolism, 14C in 14CO2 persists in the environment because its half is approximately 5,700 years. If the atmospheric carbon is produced by modern day respiration, then we would expect the concentration of 14C to 13C to remain stable over time. This has not been the case, as the ratio of 13C to 14C has significantly increased during the time of industrialization. This increase is a result of the use of ancient carbon in fossil fuels releasing more 13C into the atmosphere, conclusively proving that anthropogenic causes are responsible for increased rates of global climate change.
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The causes of global climate change and rapid climate warming have been a topic of significant political debate. This debate is largely one sided in the scientific community, as it is widely accepted that the recent rapid increase in atmospheric CO2 emissions and other greenhouse gases is a result of anthropogenic causes. Greenhouse gases, i.e. CO2, CH4 and N2O, are capable of absorbing infrared radiation radiated into space from the Earth’s surface. These gases do not absorb visible light, allowing visible light to reach Earth’s surface and be absorbed by the surface. This energy is then reflected as infrared radiation, which is captured by the absorbing atmospheric gases, resulting in a warming effect. Overall warming is in an unfortunate, positive feedback loop with melting polar icecaps as frozen areas have higher albedo resulting in less absorption of light. As the climate warms, icecaps will continue to decrease in area, resulting in a lower albedo and increased absorption of energy by land masses and increasing global temperatures.
These rises in greenhouse gases are a combination of anthropogenic factors and naturally occurring processes, but have been significantly exacerbated by recent (within 200 years) anthropogenic emissions. Increased concentrations of CO2 and CH4 in the air are a product of agricultural and industrial production of CH4 (dairy farming) and from burning fossil fuels. The burning of fossil fuels in the form of coal or natural gas (CH4) results in an increase in CO2 and CH4 greenhouse gas concentration through the oxidation of organic carbon. As industrial practices increased over the past two centuries, burning of coal consistently increased global CO2 concentrations more drastically than background natural increases.
The causes of global climate change through significant overall warming has been a topic of significant debate politically. Among the scientific community, it is widely accepted that the recent rapid increase in atmospheric CO2 emissions and other greenhouse gases is directly a result of anthropogenic causes. As greenhouse gases, CO2, CH4 and N2O are capable of absorbing infrared radiation which is radiated into space from the Earth’s surface. These gases do not absorb visible light, allowing visible light to reach Earth’s surface and be absorbed as heat energy. This energy is then reflected as infrared radiation which is captured by the absorbing atmospheric gases, resulting in a warming effect. Overall warming is in an unfortunate, positive feedback loop with melting polar icecaps as frozen areas have higher albedo and can reflect more light. As the climate warms, icecaps will continue to decrease, resulting in more absorption of heat energy by land masses and increasing global temperatures.
Turtle shell morphology is an important determinant of how successful a species will be in its environment. Fully aquatic turtles, such as loggerhead sea turtles, have tear-drop shaped shells to increase their hydrodynamics during swimming. The first third of the shell should be the thickest point followed by significant tapering towards the posterior end of the animal to reduce the effects of drag. Though these species are well adapted to life in marine ecosystems, their heavy shells, flipper front limbs, and front-heavy carapace leave them significantly exposed on land. This is especially evident when females travel on land to deposit their eggs. Their movement is quite laborious, demonstrating how infrequently they make the journey.
Conversely, terrestrial turtles experience a selective pressure towards more domed carapaces. Domed shells provide more protection against predators by distributing bite forces around the shell, reducing the likelihood of breakage. This is especially evident in fully terrestrial tortoises. Semi-aquatic species such as mud turtles experience intermediate shell thicknesses to allow for protection again land predators while still facilitating efficient swimming.
Though this patch is protected as conservation area, there is a significant amount of human traffic through the many walking trails. Organisms that inhabit this area must avoid frequent walkers, and their hiding places are rather limited considering the stretch of unbroken area. This particular patch is barely large enough to successfully harbor a population of large carnivores and a population of coyotes is well defined. It is frequented by populations of white tailed deer and other small mammals. The wetland areas and large streams running through the patch are also home to aquatic and semiaquatic organisms such as amphibians and fish. A population of brook trout are established in one stream that is an extension of the Asabet River. Since the patch is relatively irregularly shaped, animals that stray too close to the edge of the patch run the risk of collisions with cars and run-ins with humans. Wide expanses of farmland areas and busy roads block the safe passage to the next nearest undisturbed patch characterized by the Wachusett Reservoir to the North. Though inhabitants run the risk of death, they often stray beyond the patch in more suburban areas where forest cover is far more limited. White tailed deer and red foxes are two of the most frequently spotted travelers out of the conservation area.
When examining natural landscapes that I am familiar with, the patch of conservation land designated as the Mount Pisgah Conservation Area in my hometown of Northborough, Massachusetts comes to mind. This particular patch spans 83 acres across the towns of Northborough, Berlin, and Boylston. As designated conservation area, the patch is free of roads for car traffic while roads outline the edges of the conservation area on most sides. The patch is irregularly shaped with rather pointed edges in an overall rectangular shape. Though it is bordered by relatively forested areas, surrounding patches of woods are speckled with housing developments and farmland properties resulting in a loss of overall connectivity between patches. The Eastern edge has a relatively steep slope compared to the surrounding patches, but is not nearly steep enough to restrict passage of most terrestrial organisms. The vegetation is predominantly deciduous forest with smaller patches within monopolized by low hanging conifers. These patches are directly East of the steepest sloping areas where the major wetland areas can also be found.
The moss specimen examined, regardless of location, were capable of surviving desiccation and successfully rebounded in greenness.
Specimens from South, East, and West microclimates generally rebounded at similar rates, indicating that such subtle changes in microclimates may either not affect rebound success or was not detectable using our methodology.
Though the North facing specimen experienced the least successful rebound, we cannot conclude that this is solely a result of its original microclimate and that North facing mosses are generally not as successful.
- A more extensive comparison between North, South, West, and East facing moss samples from multiple trees should be conducted to determine if a different tree location produces a significant effect in more variable locations (with more extreme sun exposures depending on orientation).
If our species can remove itself from the elitist belief that humans are superior to other species, formulating laws to protect the natural world would aim to benefit biodiversity. Regulating climate changing pollution would be done for the well being of all life and not just for the lives of human beings and their monetary gains. Protecting our natural resources and the organisms that benefit from those resources by tightening regulations would be to the ultimate benefit of our species. What regulators in this country are currently too pompous or blind to see is that their money will have no value if our planet in incapable of sustaining human life. Maintaining our planet requires treating other living things with the same amount of respect and value, and we will continue to decrease biodiversity if we fail to modify our behaviors.
The initial rate of rebound in the first 10 minute period was significantly higher than at any other period of time.
Greenness decreased for North and East facing specimen from time 10 minutes to 20 minutes.
Greenness decreased from the initial point of rehydration (10 minutes) for all specimen after 40 minutes.
The rate of rehydration for South, West, and East facing specimen increased after 40 minutes resulting in higher proportions of greenness than at time 10 minutes.
North facing specimen experienced a decrease in greenness after the initial first 10 minutes of rehydration.
The overall rates of rehydration of South, West, and East facing specimen were very similar and did not differ significantly based on orientation around the tree.
- The North facing specimen had an overall slower rate of rehydration than the other specimens.
Overall, each specimen experienced a significant reduction in greenness after desiccation with the East facing specimen having a slightly less dramatic reduction.
The South, West, and East specimen all had a higher proportion of greenness after rehydration than prior to desiccation while the overall greenness decreased for the North facing specimen.
- All specimen rebounded from desiccation, but the North facing specimen had the least dramatic increase in overall greenness after 24 hours from its desiccated state.