What is the primary cause of sea-level rise?
Explanation: The correct answer is A) Melting of polar ice caps. The primary cause of sea-level rise is the melting of polar ice caps, particularly in Greenland and Antarctica. As global temperatures rise due to greenhouse gas emissions, these ice caps are losing mass, which contributes to an increase in sea levels. The melting of glaciers and ice sheets, along with the thermal expansion of seawater as it warms, are the main factors driving the rise in sea levels.
What are some impacts of sea-level rise?
Explanation: The correct answer is D) All of the above. Sea-level rise has several impacts, including increased coastal erosion, flooding of coastal areas, and salinization of freshwater sources. Rising sea levels intensify the power of waves and storm surges, leading to more significant erosion of coastlines. Low-lying coastal areas are at greater risk of experiencing frequent and severe floods, which can lead to the loss of infrastructure and displacement of communities. Additionally, saltwater intrusion into freshwater sources can contaminate drinking water supplies, affecting both humans and ecosystems.
What contributes to regional variations in sea-level rise?
Explanation: The correct answer is D) All of the above. Regional variations in sea-level rise are influenced by multiple factors. Differences in ocean currents can redistribute water mass, causing variations in sea-level rise across regions. Changes in land elevation, such as subsidence or uplift, can also affect local sea-level rise. Additionally, the melting of glaciers and ice sheets in specific regions contributes to the regional differences observed in sea-level rise.
How does sea-level rise impact coastal ecosystems?
Explanation: The correct answer is D) All of the above. Sea-level rise has significant impacts on coastal ecosystems. As sea levels rise, coastal wetlands, such as salt marshes and mangroves, are at risk of being submerged, leading to their loss. These ecosystems provide essential habitats for numerous species and contribute to biodiversity. Additionally, the rise in sea levels makes coastal areas more vulnerable to storm damage and coastal erosion, which further affects coastal ecosystems and their ability to provide services and support diverse life forms.
What are some strategies to mitigate the impacts of sea-level rise?
Explanation: The correct answer is D) All of the above. To mitigate the impacts of sea-level rise, multiple strategies can be employed. Implementing coastal defense measures, such as seawalls or dikes, can help protect vulnerable areas from coastal erosion and storm surges. Adaptation of coastal infrastructure involves designing and modifying buildings and infrastructure to withstand higher water levels and increased risks. In some cases, managed retreat may be necessary, where communities and infrastructure are relocated away from vulnerable coastal areas. These strategies, along with other measures like ecosystem-based approaches, are crucial for managing and adapting to the challenges posed by sea-level rise.