What is a significant challenge facing global ecosystems?

Habitat destruction and pollution represent significant challenges facing global ecosystems because they lead to the loss of biodiversity and the degradation of natural environments. As human activities expand—such as urban development, agriculture, and industrial processes—habitats are often destroyed or altered, making it difficult for many species to survive. Pollution, whether from chemicals, plastics, or other waste, can also have devastating effects on both wildlife and plant life, disrupting food chains and ecosystem services.

In contrast, the other options do not present the same level of threat to ecosystems. Excessive rainfall, while it can lead to localized flooding and impact agricultural practices, does not encompass the broad range of detrimental effects caused by habitat destruction and pollution. Increased biodiversity typically indicates a healthy ecosystem, reversing the damage done by habitat destruction. Similarly, the expansion of green spaces is largely seen as a positive development, contributing to environmental health by providing habitats and enhancing urban biodiversity. Therefore, habitat destruction and pollution are at the forefront of global ecological challenges, emphasizing the need for sustained conservation efforts and pollution control measures.