Final answer:
The environmental effects of an eruption similar to the one that formed Crater Lake encompass a vast range of impacts, including air pollution, ecosystem disruption, acid rain, and geological hazards like landslides and mudflows, all of which reflect the broad-reaching influence of volcanic activity on the environment.
Step-by-step explanation:
The present-day environmental effects of an eruption such as that which created Crater Lake would include all of the above options: increased air pollution due to volcanic ash and gases, disruption of ecosystems and loss of biodiversity, acid rain and water contamination from volcanic emissions, and the potential for landslides and mudflows in surrounding areas.
Historical examples like the 1980 eruption of Mt. St. Helens and the eruption of Mount Pinatubo showcase how significant the impacts can be. In the case of Mt. St. Helens, the eruption transformed lush forests into a dusty wasteland, and the ash spread across vast areas, impacting both the environment and human activities. Additionally, volcanic emissions can include a range of gases like carbon dioxide and sulfur dioxide, which contribute to haze-effect cooling and can lead to acid rain.
Further impacts such as the blocking of sunlight can result in lower global temperatures and have effects on wildlife and vegetation, thus altering ecosystems substantially. The eruption might bring about primary succession, starting with a completely barren landscape where new organisms progressively colonize the land.