Logo of Phnom Penh Post newspaper Phnom Penh Post - Atmospheric hole discovered

Atmospheric hole discovered

A rice farmer plants crops in a dried-up paddy in Kampong Speu’s Kong Pisei district in 2012
A rice farmer plants crops in a dried-up paddy in Kampong Speu’s Kong Pisei district in 2012. Scientists have discovered a large hole in the atmosphere’s lowest layer above Southeast Asia. Heng Chivoan

Atmospheric hole discovered

Scientists have discovered a new phenomenon in the skies above Southeast Asia: a huge, invisible hole in the atmosphere’s lowest layer that may exacerbate the effects of Cambodia’s climate change.

The hole – roughly twice the length of New Zealand and concentrated just east of the Philippines – is really an absence of what scientists call the “OH shield”, the atmosphere’s filtering, detergent layer that breaks down pollutants before they wreak havoc farther up.

Under normal circumstances, pollutants are reduced in the OH shield, absorbed by water vapour and washed out by rain. But with no OH shield, the polluting substances in the Western Pacific travel to higher altitudes where their ozone-depleting effect is amplified.

“You can imagine this region as a giant elevator to the stratosphere,” said Markus Rex, an atmospheric physicist who led the team of researchers from the Alfred Wegener Institute that discovered the hole.

Climatologists have known about the degradation of the ozone – the stratospheric layer that deflects dangerous ultraviolet radiation from the sun – since the 1980s, but the rate of depletion they’re seeing is faster than models predicted.

Rex and his research team set out to measure ozone levels in 2009, and years later, after hundreds of tests, confirmed the giant, natural OH hole.

“There are no indications that this is a recent development or has been caused by human activities. We believe this is a natural phenomenon that has been there for a long time,” Rex said.

While the hole in the atmosphere’s filtering system may not be human-caused, it is expected to exacerbate the anthropogenic forces of climate change, including rising air pollution levels in the region.

“It’s obvious that these chemicals have an effect on climate change and there will be impacts to Southeast Asia, we just don’t know exactly what those changes will be yet,” Rex said.

Experts say it’s too early to take mitigation measures.

“It normally takes a few years from scientific discovery, to understanding the causes, to identifying solutions,” said Napoleon Navarro, deputy country director at the UNDP Cambodia.

To start piecing together how the OH hole will fit into the climate-change puzzle, the EU is funding a $12.5 million “Strato-Clim” monitoring centre. Meanwhile, scientists are predicting worldwide repercussions.

“If the emissions are transported up to the stratosphere . . . they have the potential to not only have impacts in Southeast Asia and Cambodia, but globally as well,” said Erika von Schneidemesser, an atmospheric research scientist at the German-based Institute for Advanced Sustainability Studies.

MOST VIEWED

  • Angkor Wat named as the top landmark for the second year

    Travel website TripAdvisor has named Cambodia’s ancient wonder Angkor Wat as the top landmark in the world for the second year running in their Travelers’ Choice Award 2018, an achievement Cambodian tourism operators expect will attract more tourists to the Kingdom. The website uses traveller

  • New US bill ‘is a violation of Cambodian independence’

    After a US congressmen introduced bipartisan legislation that will enact sanctions on Cambodian officials responsible for “undermining democracy” in the Kingdom, government officials and the ruling Cambodian People’s Party on Sunday said they regarded the potential action as the “violation of independence and sovereignty

  • Hun Sen detractors ‘will die’

    Prime Minister Hun Sen on Wednesday said those who curse or insult him would eventually die without a plot of land to bury their bodies after being killed by lightning, suffering the same fate as those who recently died in Thmar Baing district in Koh

  • Ministry’s plan for net sparks fears

    The government has ordered all domestic and international internet traffic in the Kingdom to pass through a Data Management Centre (DMC) that has been newly created by the state-owned Telecom Cambodia, in a move some have claimed is an attempt to censor government critics. Spokesman