Abstract This research presents credible evidence that supports the existence of global warming. A graph by the National Aeronautics and Space Administration demonstrates that the earth’s temperature has rising faster than in 650,000 years. The effects of these changes are significant on the ecosystem and human populations. A second graphic demonstrates the loss of coastal read if all of the ice sheets on earth were to melt. The most significant changes demonstrated by this graph are to the eastern coast of the United States and the loss of Florida. The acidification of the oceans is another effect of global warming and greenhouse gases. A graph demonstrating the effects of CO2 caused by human activity accounts for a major increase in greenhouse gases and the effects that are being seen as a result of global warming.
Global Warming: Credible Evidence
Global warming is one of the most controversial topics in the world today. Global warming describes a condition where the average temperature of the earth’s atmosphere and oceans increase. Global warming is predicted to have significant harmful effects on life on earth. The controversy arises from conflicting evidence in the scientific community as to whether humans are contributing to global warming, whether it is a result of natural forces that are beyond the control of humans, or in some cases, whether it is even occurring at all. This research will examine credible evidence of global warming and will explore its causes and effects.
Some of the most compelling evidence that climate change is real comes from NASA’s Jet Propulsion Laboratories. They examined the years the average temperature data over the last 650,000 years. Although the earth’s temperature has risen and fallen several times over this period, the earth’s temperature today is higher than it has ever been (1). The following chart represents the earth’s average temperature over the last 650,000 years, according to NASA.
Greenhouse gases have an effect on the transfer of energy in the infrared spectrum throughout the atmosphere. Increased greenhouse gases cause the earth’s temperature to rise. Ice cores drawn from Antarctica, Greenland, and several tropical mountains demonstrate that the earth’s climate changes in response to greenhouse gases (2). Furthermore, evidence from the NRC demonstrates that these changes can happen quickly in tens of years, rather than longer periods of hundreds or thousands of years. Earth’s climate changes happen rapidly, as compared the geologic changes that take thousands or even millions of years (2).
This evidence combined with evidence presented by NASA, makes it difficult to argue that climate change is not occurring, or that it is happening rapidly. Now it is time to examine some of the effects of climate change and how they could impact Life on earth.
According to The report by the American Meteorological Society, the 20 warmest years have occurred since 1981 (3). The 10 warmest years have occurred in the past 12 years, even though solar energy output has declined over the same period (3). The earth’s temperature continues to rise even though the energy from the sun reaching the earth has decreased. This increase in temperature has the potential to affect plants and animals that can only survive in certain temperature ranges. It also means that in some cases new plant species and animals will be able to survive where they could not in the past. This will place strain and produce many changes in local ecosystems, some of which may be beneficial and others which may be harmful. It will affect the types and production of crops in certain areas as well.
Another effect of warming global temperatures is a drop in the size of the arctic sea ice sheet. An examination of the ice sheets in the earth’s geologic past found that the Arctic ice sheets became a feature of the earth after a decline in atmospheric carbon dioxide that occurred after the Paleocene-Eocene thermal optimum (4). Since that time, the Arctic ice sheet has covered at least part of the arctic ocean consistently for the past 13 to 14 million years. It has been the largest ever in the earth’s history over the past 2 to 3 million years (4). The reduction of the current arctic ice covering began in the late 19th century, with most pronounced loss occurring over the last three decades (4). Experts at the U.S. Geological Survey agree that this loss appears to be unmatched over the course of the earth’s history and that natural variability fails to explain its rapid progress (4). All of this melting ice will have an impact on human life and the ecosystem, particularly in coastal areas. It will mean the loss of real estate and habitable areas, pushing people further inland. In addition, the inundation of salt water into previously fresh water areas will have an environmental impact on plants and animals in these areas. The following visualization shows the loss of coastal areas if all of ice on earth were to melt.
Another effect of an increase in carbon dioxide in the atmosphere is acidification of the oceans. When CO2 Is absorbed by seawater a chemical reaction occurs that reduces the pH of the seawater (5). It also reduces a saturation points of calcium carbonate minerals. A reduction of calcium carbonate means that animals that rely on this mineral for the structure of their skeletons and shells are not be able to maintain them (5). This has an effect on pteropods, shellfish, and corals. Currently, ocean acidification is blamed for a reproduction failure in oysters, and a reduction in commercially important shellfish (5). At the current rate, carbon dioxide absorbed by the top layer of the ocean to is increasing at a rate of about two billion tons per year (5).
One of the biggest questions concerning the climate change issue is whether humans are having an impact, or whether this is simply a result of natural processes. A recent assessment report of the Intergovernmental Panel on Climate Change (IPCC) states that it is now almost 90% certain that emissions of greenhouse gases are a result of human activities and that humans have caused the recent spike in global temperatures (6). One of the ways that they can determine this is that carbon molecules are not all the same. Carbon molecules in the atmosphere that are from the burning of fossil fuels and deforestation are lighter than the combined signal from natural sources. They can now measure the weight of the carbon in the atmosphere and see an increase in the lighter molecules that are a signature of fossil fuel and deforestation (6). This ability to detect carbon from human sources as opposed a natural sources allows them to compare atmospheric increases in these types of carbon molecules with trends in emissions. The evidence indicates that these two elements correlate (6). The following graphic demonstrates the effect that the fossil fuel fingerprint in comparison to total atmospheric CO2.
In conclusion, evidence from credible governmental and intergovernmental agencies demonstrates that the temperature of the earth has experienced an unprecedented cent increase in global temperature. In addition, the ability to distinguish various types of carbon in the atmosphere makes the role of humans in this increase difficult to deny. These changes have a significant impact on local ecosystems and will continue to have increasing effects on human food sources, severe weather events, and the loss of currently habitable coastal space. Plants and animals must continue to adapt to a changing environment. This will inevitably cause the loss of some species, and the proliferation of others. The results of these changes are difficult to predict, but their existence can now no longer be denied.
- Nation Aeronautics and Space Administration (NASA). Climate change: How do We know? 2015. http://climate.nasa.gov/evidence/. Accessed October 28, 2015.
- National Research Council (NRC). Surface Temperature Reconstructions for the Last 2,000 Years. 2006. http://oceanservice.noaa.gov/education/pd/climate/teachingclimate/surftemps2000yrs.pdf. Accessed October 28, 2015.
- Peterson, T. & Baringer, m (Eds.). State of the Climate in 2008. Special
Supplement to the Bulletin of the American Meteorological Society, 90 (8): S17-
S18. Accessed October 28, 2015. http://clima.meteoam.it/Documenti/turchia-report.pdf. Accessed October 28, 2015.
- Polyak, L., Alley, R., Andrews, J. & Brigham-Grette, J. et al. History of Sea Ice in the Arctic, U.S. Geological Survey. 2009. Quarternary Science Reviews. 29 (15/16): 1757-1778. 2009. http://research.bpcrc.osu.edu/geo/publications/polyak_etal_seaice_QSR_10.pdf. Accessed October 28, 2015.
- National Oceanic and Atmospheric Administration (NOAA). What is Ocean Acidification. PMEL Carbon Program. 2015. http://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F. Accessed October 28, 2015.
- Union of Concerned Scientists. How Do We Know that Humans are the Major Cause of Global Warming? 2015. http://www.ucsusa.org/global_warming/science_and_impacts/science/human-contribution-to-gw-faq.html. Accessed October 28, 2015.