After a major rise of temperatures since the beginning of the 20th century, global warming seems to have taken a break for the last 15 years. Scientists have been looking into the possible causes of the warming hiatus over the past few years. Solar cycles, oceans storing up heat from global warming, are some of the possible explanations, but recently, volcanoes have emerged as a potential factor for this “cooldown”.
Volcanic eruptions spew small particles and aerosols into the stratosphere which scatter sunlight back into space and block Earth’s thermal radiation preventing the global average temperature from rising. For example, the Philippines’s Mount Pinatubo, cooled off Earth by a few tenths of a degree Celsius for months after it erupted on June 5, 1991.
Climate projections don’t include the effects of volcanic eruptions as they are almost impossible to anticipate. Only major eruptions such as Mount Pinatubo in 1991, were thought to impact global climate. However new observations have found that volcanic eruptions contributed to lower global surfaces temperatures by 0,08C during what is called the “global warming hiatus”.
Hopefully this new data will help scientists to build more robust climate models including also the impact of aerosols on climate change.