Environmental Chemistry: Atmosphere and Water - SS2 Chemistry Past Questions and Answers - page 4

The greenhouse effect is a natural process that regulates the Earth's temperature by trapping heat in the atmosphere. It plays a vital role in maintaining a habitable climate for life on Earth. The greenhouse effect works as follows:

●     Solar radiation from the Sun reaches the Earth's surface.

●     The Earth's surface absorbs some of this radiation and radiates it back as heat.

●     Greenhouse gases in the atmosphere, such as carbon dioxide (CO2), methane (CH4), and water vapour, absorb and re-radiate this heat, trapping it in the lower atmosphere.

●     This trapped heat warms the Earth's surface and lower atmosphere, creating the stable climate conditions we experience.

Greenhouse gases are responsible for the greenhouse effect. Carbon dioxide is primarily released from burning fossil fuels, deforestation, and industrial processes. Methane is emitted from agricultural activities, livestock, landfills, and the extraction of fossil fuels. Water vapour is naturally present in the atmosphere and its concentration varies with temperature and humidity.

An enhanced greenhouse effect refers to the increased concentration of greenhouse gases in the atmosphere, primarily due to human activities. This increase leads to an imbalance in the natural greenhouse effect, resulting in additional heat being trapped and an overall rise in global temperatures. The implications of an enhanced greenhouse effect include:

●     Global Warming: The increased trapping of heat leads to global warming, causing a rise in average global temperatures. This warming has far-reaching impacts on ecosystems, weather patterns, sea levels, and biodiversity.

●     Climate Change: Global warming, driven by the enhanced greenhouse effect, leads to shifts in climate patterns, including altered precipitation, changes in seasons, and more frequent and intense extreme weather events such as heatwaves, droughts, floods, and storms.

●     Melting of Ice Caps and Glaciers: Rising temperatures result in the melting of ice caps and glaciers, contributing to sea-level rise. This poses risks to coastal communities, ecosystems, and infrastructure.

●     Ocean Acidification: Increased carbon dioxide levels from the enhanced greenhouse effect lead to ocean acidification. This harms marine life, especially organisms that rely on calcium carbonate for their shells and skeletons.

Addressing the enhanced greenhouse effect and its consequences is crucial to mitigate the impacts of climate change and ensure a sustainable future.

Global warming refers to the long-term increase in Earth's average surface temperature. It is primarily caused by the increase in greenhouse gases, particularly carbon dioxide, in the Earth's atmosphere. The role of greenhouse gases and human activities in driving global warming can be summarised as follows:

●     Greenhouse Gas Emissions: Human activities, such as the burning of fossil fuels (coal, oil, and natural gas), deforestation, industrial processes, and agriculture, release significant amounts of greenhouse gases into the atmosphere. These emissions enhance the greenhouse effect, leading to global warming.

●     Positive Feedback Loops: Global warming triggers positive feedback loops that amplify the warming process. For example, as temperatures rise, ice and snow melt, reducing the Earth's albedo (reflectivity) and causing more solar radiation to be absorbed, leading to further warming.

The consequences of global warming are far-reaching and include:

●     Rising Temperatures: Global warming leads to higher average temperatures worldwide, affecting ecosystems, agriculture, water resources, and human health.

●     Melting Ice and Rising Sea Levels: As temperatures rise, ice caps and glaciers melt, contributing to sea-level rise. This poses risks to coastal communities, low-lying areas, and ecosystems.

●     Extreme Weather Events: Global warming increases the frequency and intensity of extreme weather events such as heatwaves, droughts, floods, and storms. These events have significant socio-economic and environmental impacts.

●     Ecosystem Disruption: Global warming disrupts ecosystems, affecting biodiversity, species distribution, and ecological interactions. It can lead to habitat loss, species extinction, and disruptions in ecosystem services.

Mitigating global warming requires collective efforts to reduce greenhouse gas emissions and transition to a low-carbon economy. Measures to mitigate global warming include:

●     Transition to Renewable Energy: Promoting and investing in renewable energy sources such as solar, wind, and hydropower can reduce reliance on fossil fuels and decrease greenhouse gas emissions.

●     Energy Efficiency: Improving energy efficiency in buildings, transportation, and industries can significantly reduce energy consumption and associated emissions.

●     Forest Conservation and Reforestation: Protecting existing forests and reforesting degraded areas can enhance carbon sequestration, mitigating greenhouse gas concentrations.

●     Sustainable Agriculture: Implementing sustainable agricultural practices, such as precision farming and organic farming, can reduce emissions from agricultural activities and enhance carbon sequestration in soils.

●     International Cooperation: Encouraging international agreements and collaborations to reduce greenhouse gas emissions and address global warming, such as the Paris Agreement.

These measures, along with individual actions, policy changes, and technological advancements, are crucial for mitigating global warming and reducing its impacts.