What is often considered the most significant long-term impact of global warming?

The most significant long-term impact of global warming is the occurrence of prolonged droughts and floods. As the Earth's temperatures rise, climate patterns are altered, leading to extreme weather events. These changes can intensify the severity and frequency of both droughts and heavy rainfall.

Droughts can become prolonged due to altered precipitation patterns and increased evaporation rates, while heavier rainfall can lead to severe flooding. Such conditions can adversely affect ecosystems, agriculture, and water resources, resulting in serious consequences for food security and biodiversity.

In contrast, temporary weather changes do not capture the enduring nature of the impacts of global warming, and while increased agricultural output might occur in specific regions due to longer growing seasons, it is not a universal outcome and does not address the overall negative effects of climate change. The widening of the ozone layer is also unrelated, as it pertains more to stratospheric chemistry than to the impacts of global warming. Thus, prolonged droughts and floods represent a critical, ongoing challenge as global temperatures continue to rise.