Volcanic eruptions have significant environmental impacts, especially when active volcanoes erupt. Some of the largest eruptions in history, such as the Krakatoa eruption in Indonesia in 1883 and the Merapi eruption in 2010, show how powerful the influence of volcanism is on the global ecosystem and climate. One of the main impacts of volcanic eruptions is the emission of volcanic gases, including sulfur dioxide (SO2), carbon dioxide (CO2), and water vapor gas. These gases can affect air quality and contribute to the formation of aerosol clouds that reduce solar radiation. In the case of the Krakatoa eruption, sulfur dioxide emissions caused global temperatures to drop for several years, which had an impact on weather patterns and agriculture. Fine particulates from the eruption also affect the quality of the soil and surrounding ecosystem. The volcanic ash emitted is often rich in minerals and can fertilize the soil, but in large quantities it can damage vegetation and cause erosion. For example, the eruption of Merapi destroyed agricultural fields and caused increased sedimentation in rivers, which impacted aquatic life. Natural disasters that occur after eruptions, such as lava and landslides, are also a major concern. Lava, a mixture of sand, rock and fast-moving water, can destroy habitats and infrastructure. This phenomenon often follows eruptions and spreads to areas far from the eruption point, as happened after the eruption of Merapi. The social and economic impact of volcanic eruptions cannot be ignored. Many communities depend on agriculture, and damage to farmland from eruptions can lead to famine and forced migration. The presence of volcanic ash in the air also disrupts transportation and daily activities. In addition, the psychological impact on communities experiencing this disaster is quite large, with the risk of increasing mental health problems. Having a positive impact, volcanic eruptions can produce fertile land for agriculture in the long term, as long as recovery is carried out effectively. For example, many areas near volcanoes have successfully used mineral-rich soil as a food source. This approach requires time and effort in managing the post-eruption ecosystem. Stretching the living space for flora and fauna also creates its own challenges. Some species may become extinct, while others may reproduce rapidly in newly formed areas. The success of species in adapting to new environments is often an important aspect in understanding the long-term impacts of volcanic eruptions. In the context of climate change, volcanic eruptions release significant amounts of CO2, although their contribution is small compared to emissions from human activities. However, global warming and its impact on climate patterns can be affected by volcanic activity. Research shows that large eruptions can prolong the cooling effect already present in the atmosphere due to greenhouse gas emissions. Disaster mitigation strategies are critical, especially for countries located on the “Pacific Ring of Fire” that are vulnerable to eruptions. Early warning systems and evacuation plans must be strengthened to protect the public. Apart from that, post-eruption environmental rehabilitation efforts need to be considered to restore disturbed ecosystems. The importance of multidisciplinary research on the impacts of volcanic eruptions encourages collaboration between scientists. Understanding every aspect of an eruption can help in predicting and mitigating the negative effects it causes. As global climate patterns change, the study of volcanoes becomes increasingly relevant for responding to upcoming environmental challenges.