Taal_Hightest SO2 emissions level ever recorded yesterday.What is mean?

Sulfur dioxide indicates magma is near the surface

Sulfur dioxide (SO2) is released from a volcano when magma is relatively near the surface. If SO2 is detected at a non-erupting volcano, it could be a sign that it will erupt soon. By monitoring the amount of SO2 being emitted from an active volcano, it is possible to calculate the amount of magma that is supplying the eruption. However, SO2 easily dissolves in water, so if the volcano has abundant surface or subsurface water (e.g. glaciers, crater lakes, a hydrothermal system) it becomes difficult and sometimes impossible to determine how much sulfur dioxide is actually being released. A variety of spectrometers (e.g., COSPEC and DOAS) are used to measure the volcanic emissionrate of sulfur dioxide gas.

When SO2 is injected into the atmosphere, it quickly forms potentially hazardous sulfate areosols. They can cause respiratory problems to people downwind of a volcanic plume (e.g VOG—volcanic smog). If injected into the upper atmosphere (stratosphere), they can cool the climate for years by reflecting incident sunlight back to space.