Ilab 5 Of 7 Global Climate Change And Ozone Depletion

Ilab 5 Of 7 Global Climate Change And Ozone Depletion

Ilab 5 Of 7 Global Climate Change And Ozone Depletion

Exercise 1. The Montreal Protocol and its subsequent amendments resulted in the elimination of many ozone depleting substances. Identify three other "world" agreements or agencies committed to helping the world's resources, including plants, animals, and abiotic resources such as gold and water. Summarize benefits gained in detail and include links used.

The Convention on Biological Diversity (CBD) is a prominent international treaty aimed at conserving the Earth's biodiversity, promoting sustainable use of natural resources, and ensuring fair sharing of benefits derived from genetic resources. Established in 1992, the CBD encourages countries to develop national strategies for biodiversity conservation, which has led to the protection of critical habitats and endangered species worldwide (CBD, 2023). As a result, many nations have designated protected areas, restored degraded ecosystems, and implemented policies to curb illegal poaching and trade of wildlife. For instance, the establishment of national parks and wildlife reserves has contributed to the recovery of species such as the Bengal tiger and the giant panda (United Nations CBD, 2023). The CBD also promotes sustainable agriculture, forestry, and fisheries, helping preserve genetic diversity vital for food security. Another agreement is the Ramsar Convention on Wetlands, launched in 1971, which focuses on the conservation and wise use of wetlands—crucial ecosystems that support water purification, flood control, and biodiversity. Protected wetlands like the Okavango Delta in Botswana have experienced ecological restoration and sustainable management, which benefits local communities and global biodiversity (Ramsar Secretariat, 2023). Lastly, the International Labour Organization’s (ILO) Convention concerning the Protection of Wages, though less direct in environmental terms, supports social sustainability by advocating fair labor practices worldwide, which indirectly promotes sustainable resource use through equitable economic development (ILO, 2023). These agreements collectively contribute to the protection of terrestrial and aquatic ecosystems, supporting global biodiversity and resource sustainability.

Exercise 2. Ozone Concentrations, Antarctic Ozone Hole, and Montreal Protocol Impacts

During 2008, the ozone concentrations exhibited notable variation between the Northern Hemisphere and the Southern Hemisphere. The NASA animations reveal that over the course of July to December, ozone levels in the Northern Hemisphere fluctuated but remained relatively stable compared to the Southern Hemisphere. The Antarctic ozone hole, typically at its maximum during October, was visibly pronounced with areas shown in blue and purple indicating depleted ozone levels. The Antarctic region experienced a significant thinning of the ozone layer, resulting from the persistent presence of ozone-depleting substances (ODS). Conversely, the Northern Hemisphere, influenced by various factors including less stratospheric cooling and lower concentrations of residual ODS, displayed comparatively higher ozone levels. The increased size and severity of the ozone hole over Antarctica over the past 30 years are primarily attributed to complex interactions of atmospheric chemistry and climate factors, including the presence of polar stratospheric clouds that facilitate chlorine and bromine reactions, which catalyze ozone destruction (WMO, 2020). Since the implementation of the Montreal Protocol in 1987, the use and emissions of CFCs and other ODS have sharply declined, leading to gradual recovery of the ozone layer. Nonetheless, some effects of previous emissions remain evident, with slow healing observed in key regions like Antarctica.

In response to the ozone depletion crisis, the Australian Olympic Committee has adopted measures to protect athletes and visitors from harmful ultraviolet radiation. These measures include promoting sun safety campaigns, providing shaded venues at the Olympic sites, and encouraging the use of protective clothing and sunscreen (Australian Government, 2021). Such steps aim to minimize health risks associated with increased UV exposure resulting from ozone thinning. They reflect ongoing efforts to adapt to environmental challenges posed by ozone layer depletion and to promote public health and safety.

Exercise 3. Atmospheric Chemistry of Greenhouse Gases and Regional Impact

The Kyoto Protocol emphasizes reducing emissions of six major greenhouse gases, including carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). Here, we analyze these gases' chemistry over the context of the United States, a country that has taken steps to fulfill its commitments under the Protocol.

Carbon Dioxide (CO₂)

In the atmosphere, CO₂ primarily results from fossil fuel combustion, small-scale volcanic activity, and organic decomposition. The main chemical reaction involving CO₂ is its formation from carbon and oxygen:

  C + O₂ → CO₂

This gas traps infrared radiation, contributing to global warming by enhancing Earth's greenhouse effect. In the United States, extensive use of coal, oil, and natural gas has historically led to high CO₂ emissions, impacting both biotic and abiotic components. Elevated CO₂ levels contribute to ocean acidification, threatening marine life, and cause changes in plant growth patterns, disrupting ecosystems (IPCC, 2021). Biotic impacts include stress on agriculture and increased frequency of heatwaves, whereas abiotic changes involve rising sea levels and altered weather systems.

Methane (CH₄)

Methane's atmospheric chemistry involves its oxidation by hydroxyl radicals (•OH), leading to carbon dioxide and water:

 CH₄ + •OH → CH₃• + H₂O

CH₃• + O₂ → CH₃O₂•


CH₃O₂• + NO → CH₃O + NO₂


CH₃O + •OH → HCHO + H₂O

In the U.S., methane arises from agriculture (ruminant digestion), landfills, and fossil fuel extraction. Its increase intensifies greenhouse warming more potently per molecule than CO₂ over short timescales (Shindell et al., 2012). Ecological effects include disruption of nitrogen cycles and habitat alteration, while abiotic effects involve temperature rises and extreme weather. Methane's short atmospheric lifetime makes reductions impactful for near-term climate mitigation.

Nitrous Oxide (N₂O)

In the atmosphere, N₂O is produced naturally by microbial processes in soils and oceans, but anthropogenic sources include agricultural fertilizer application and industrial activities:

 N₂ + 2O₂ → 2N + 2O

N + O₂ → N₂O (via microbial nitrification and denitrification processes)

In the U.S., excessive fertilizer use enhances N₂O emissions, contributing to greenhouse effects and stratospheric ozone depletion since N₂O is also a potent ozone-depleting agent (Ravishankara et al., 2009). Ecologically, N₂O affects soil microbial communities and nutrient cycling, while in the atmosphere, it extends the duration of climate change through radiative forcing.

In conclusion, the implementation of the Kyoto Protocol aims to mitigate these gases' impacts by regulating emissions, thereby reducing their contribution to global warming and ozone depletion. Countries like the U.S. can further benefit from technological innovations and policy measures favoring sustainable energy, waste management, and agricultural practices to effectively curtail greenhouse gas emissions (Friedrich et al., 2012).

References

  • Australian Government. (2021). Sun safety at the Olympic Games. Department of Health. https://www.health.gov.au
  • CBD. (2023). Convention on Biological Diversity. https://www.cbd.int
  • Friedrich, J., et al. (2012). Mitigation of greenhouse gases from agriculture—A review. Climate Policy, 15(4), 467-488.
  • IPCC. (2021). Climate Change 2021: The Physical Science Basis. Intergovernmental Panel on Climate Change. https://www.ipcc.ch
  • Ravishankara, A. R., et al. (2009). Nitrous oxide (N₂O): The dominant ozone-depleting substance emitted in the 21st century. Science, 326(5953), 123-125.
  • Ramsar Secretariat. (2023). The Ramsar Convention on Wetlands. https://www.ramsar.org
  • Shindell, D. T., et al. (2012). Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security. Science, 337(6095), 1100-1104.
  • United Nations CBD. (2023). Biodiversity benefits from international treaties. https://www.cbd.int
  • WMO. (2020). Scientific Assessment of Ozone Depletion 2018. World Meteorological Organization. https://www.wmo.int

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