Global Warming and Environmental Science

Solar and Volcanic Activity

Physical Climate models are unable to reproduce the rapid warming observed in recent decades when considering only variations in solar output and volcanic activity. As the Sun is that the Earth's primary energy source, changes in incoming sunlight directly affect the climate system. If solar variations were liable for the observed warming, warming of both the troposphere and therefore the stratosphere would be expected, but that has not been the case.

Explosive volcanic eruptions represent the most important natural forcing over the economic era. When the eruption is sufficiently strong (with Sulphur dioxide reaching the stratosphere) sunlight are often partially blocked for a few of years, with a temperature signal lasting about twice as long. In the industrial era, volcanic activity has had negligible impacts on global temperature trends.