What role do coastal dunes play in environmental protection?

Coastal dunes serve a vital role in environmental protection primarily by acting as a buffer against storm surges. When tropical storms or hurricanes approach coastal areas, these dunes absorb some of the energy from the incoming waves and storm surge, thereby reducing coastal erosion and protecting inland habitats, infrastructure, and human communities. The height and composition of the dunes can significantly diminish the impact of high water levels, making them essential for mitigating the effects of intense weather events.

While the other options speak to important ecological functions, they do not directly address the primary protective role of coastal dunes in storm scenarios. For instance, trapping nutrients is more characteristic of wetlands, and while offering insulation to wildlife is beneficial, it is not a primary function attributed to coastal dunes. Similarly, the filtering of pollutants is more related to other environmental features such as marshes and estuaries. Therefore, option C highlights the most critical function of coastal dunes in safeguarding coastal environments and communities.