The Sangeang Api volcano in Indonesia began erupting on May 30, vaulting ash, along with tiny particles known as volcanic sulfur aerosols, as high as 65,000 feet into the stratosphere. Dramatic images from the eruption show the mountain exploding like a mushroom cloud.

The ash grounded air traffic in northwest Australia and parts of Indonesia, since those aerosols are hazardous to modern high bypass turbofan engines and can cause them to shut down in mid-flight.

Giant volcanic eruptions — the most famous being the 1883 eruption of Krakatoa, also in Indonesia — are well-known for their ability to temporarily cool the Earth. But this eruption, even counted alongside a concurrent one in Alaska, are not large enough to make much of an impact on the planet's temperature trends on their own.

See also: Volcanic Ash Disrupts Flights in Australia and Bali

The Sangeang Api volcano is located in the tropics, along the so-called Ring of Fire where the Earth's tectonic plates meet one another, leading to all sorts of geological hazards, from volcanoes to earthquakes.

When volcanoes such as this one erupt, they can emit large amounts of sulfur dioxide, which acts to make the atmosphere more opaque, thereby shielding the planet from some of the sun's incoming radiation.

This effect can theoretically offset some of the influence of manmade greenhouse gases, which trap heat inside the atmosphere and warm the planet.

But Alan Robock, a professor at Rutgers University in New Jersey and a longtime researcher on volcanic influences on the climate, told Mashable that neither the Sangeang Api eruption nor a previous one at Mt. Semeru, also in Indonesia, put enough sulfur into the stratosphere "to have any climate effect, even like the ones of the past decade."

Robock estimates that Sangeang Api has lofted about 0.1 teragrams of sulfur dioxide into the air — much of which did not make it into the upper reaches of the stratosphere, where it would have had the greatest possible influence.

However, these volcanic events are the latest in a "swarm" of tropical eruptions since 2000 that have transported enough sulfur dioxide into the upper atmosphere to reduce recent global warming.

Line plot of global mean land-ocean temperature index (degrees Celsius), 1880 to present, compared to 1951-1980. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates. Image: NASA GISS

The Sangeang Api eruption is especially noteworthy because it is occurring in the tropics — and recent scientific research has shown that tropical eruptions, even small ones, can have an outsized impact on the climate. A study published in the journal Nature Geoscience in February found that small tropical eruptions since 2000 has contributed to a slowdown in the rate at which global average surface temperatures increased in recent years.

"Tropical eruptions are usually more effective at cooling the climate compared to a high latitude eruption that is the same size, because it has the potential to impact both hemispheres and the aerosol topically stays in the atmosphere longer," says Ryan Neely, a researcher at the University of Colorado at Boulder who has been examining the influence of sulfur dioxide emissions from volcanoes.

In addition to volcanoes, factors such as increased air pollution in Asia and the uptake of an unusual amount of heat into the deep oceans have also been implicated in the temporary, short-term slowdown.

A 2011 study published in the journal Science found that if stratospheric aerosols remain at elevated levels, the magnitude of future global warming may be somewhat masked — but not mitigated.

Yet another recent study, also published in Nature Geoscience in February, found that the 21st century increase in volcanic aerosol emissions could account for up to one-third of the temperature slowdown, also known as the "warming hiatus."

Whether this cooling influence will continue is an open question. But the eruption of tropical volcanoes such as Mt. Kelud in Indonesia in February, and now the eruption of Sangeang Api, suggest the swarm is not subsiding.

"We do not know, of course, how volcanic activity will evolve over the coming decade," says Benjamin Santer, a climate researcher at Lawrence Livermore National Laboratory and coauthor of the study published in February on post-2000 eruptions. "I find it quite fascinating that the swarm ... of early 21st century volcanic eruptions continues."

Neely told Mashable scientists still need to determine exactly how much volcanic sulfur aerosols and other particles the recent eruptions put into the stratosphere in order to determine their climate impact.