Volcanic eruptions are natural events that occur when there is a sudden release of magma, gas, and other materials from a volcano. The process of volcanic eruptions can be divided into several stages:

1. Magma Formation: Volcanic eruptions start deep within the Earth's mantle, where rock melts due to high temperatures and pressure. This molten rock, called magma, is lighter than the surrounding solid rock, so it rises towards the surface.

2. Magma Chamber: The magma collects in a magma chamber, a reservoir-like structure located beneath the volcano. As more magma accumulates, the pressure within the chamber increases.

3. Gas Saturation: Magma contains dissolved gases, such as water vapor, carbon dioxide, and sulfur dioxide. As the magma rises and the pressure decreases, the gases start to separate from the magma and form bubbles. This process is similar to opening a soda bottle, where the decrease in pressure causes the carbon dioxide in the liquid to come out as bubbles.

4. Vent and Conduit Formation: As the pressure continues to build, the magma looks for a path to the surface. It can create channels called conduits that connect the magma chamber to the surface. The magma reaches the surface through an opening called a vent.

5. Volcanic Eruption: When the pressure in the magma chamber becomes too great, the magma is forcefully ejected from the vent during an eruption. The eruption can take different forms, including explosive eruptions and effusive eruptions:

   • Explosive Eruptions: These are characterized by a violent release of magma, gas, and other materials. The eruption is triggered when the pressure causes the magma to fragment into pieces called pyroclasts. Pyroclastic material, such as ash, rocks, and lava fragments, is forcefully expelled into the atmosphere, forming volcanic ash clouds and pyroclastic flows. Explosive eruptions can be highly destructive, with the potential to cause ashfall, landslides, and even volcanic mudflows known as lahars.

   • Effusive Eruptions: In these eruptions, the magma is less explosive and flows more freely. The magma rises to the surface and forms lava flows that slowly move down the volcano's slopes. Effusive eruptions are typically less dangerous but can still cause damage to the surrounding areas.

After the eruption, the volcano may enter a period of quiescence, where it remains dormant for an extended period, or it may continue to exhibit volcanic activity. Volcanic eruptions are closely monitored by scientists to provide early warning systems and mitigate potential hazards to human populations living near active volcanoes.

According to the National Aeronautics and Space Administration (NASA), the average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade. Keep in mind that this is a global average and the increase in temperature can vary significantly based on the region you're considering.