The correct option is 2 only
Explanation
Environmental impact refers to the alteration of the natural environment by human activity. This includes the degradation of ecosystems (biomes), pollution of water bodies, and depletion of natural resources, all of which affect biodiversity and food security.
Statement 1 is Incorrect: Overgrazing occurs when plants are exposed to intensive grazing for extended periods without sufficient recovery time, leading to soil erosion and the degradation of grasslands into wastelands. Similarly, overharvesting (overfishing) has led to the collapse of many major fisheries worldwide, disrupting aquatic food webs and reducing biodiversity.
Statement 2 is Correct: Coastal waters do not remain largely clean. While the ocean has a dilution capacity, coastal zones are heavily impacted by land-based activities. They receive high loads of pollutants, including sewage, agricultural runoff (fertilizers and pesticides), industrial waste, and plastics. This has led to the formation of hypoxic "dead zones" and severe degradation of coastal ecosystems like mangroves and coral reefs.
Statement 3 is Incorrect: Water depletion has had a significant negative impact on global food production. Agriculture consumes a vast majority of the world's freshwater resources. The depletion of aquifers and the drying up of rivers limit irrigation capabilities, thereby reducing crop yields and threatening global food security.
Key Takeaway: Anthropogenic pressures, including overexploitation of resources and pollution, have severely degraded key ecosystems such as grasslands and coastal waters, directly compromising global food production systems.