Japan's Deadly Earthquake May Have Weakened Our Ozone

We all remember the terrible earthquake and tsunami that left the Pacific coast of Tōhoku in ruins. Nearly 16,000 people tragically died that day, with an additional 2,500 people never found. Now new research has revealed that people and infrastructure weren't the only things to be harmed that day. Because such a stunning number of buildings were destroyed during the disaster, experts now believe that tons of harmful gases were released into the atmosphere, tearing a worrying hole in the ozone layer above Japan.

That's at least according to a study recently published in the journal Geophysical Research Letters, which details how the destruction and damage in Tōhoku released a surprising 6,600 metric tons (7,275 US tons) of gases stored in insulation, appliances and other equipment - called halocarbons - into the atmosphere. That's the equivalent of 19.2 million metric tons (21.2 million US tons) of carbon dioxide.

Takuya Saito, a senior researcher at the National Institute for Environmental Studies in Tsukuba, Japan,  explained in a recent release that this work describes a new source of potential harmful emissions never before considered.

According to the study, a worrying number of those halocarbons were chemicals that notably thin Earth's protective ozone shield - a layer of our atmosphere that absorbs most of the Sun's harmful ultraviolet (UV) radiation. Some of the gases were even identified as outdated means of insulation - materials banned in Japan and other developed parts of the world for that very effect.

CFC-11, for instance, is a powerful ozone-depleting chemical that was used in foam insulation until it was phased out in 1996. And yet the researchers found that this was one chemical in the gaseous cocktail that ate into the ozone shield just over Japan in 2011. Depending on the region, typical halocarbon levels spiked anywhere between 21 to 91 percent. What's more, emissions totaled up to the equivalent of 1,300 metric tons (1,433 US tons) of CFC-11 alone. That's equal to the amount of CFC-11 found in 2.9 million refrigerators manufactured before the chemical was banned. (Scroll to read on...)

Saito and his colleagues also determined that emissions of CFC-11 alone were 72 percent higher than emissions before the quake, confirming that the spike in halocarbons was a direct result of building and appliance damage.

The consequence was that Japan saw a surge in ozone thinning by about 38 percent between March 2011 to February 2012, as compared to the same time period the year before.

But what's important about this anyways? It's not like magnitude 9.0 earthquakes and extensive building damage hit Japan or any other country regularly. A 91 percent hike in carbon emissions for less than a year in one Japanese region is but a drop in the bucket compared to what climatologists are worried about.

However, Saito and his team are quick to point out that this data could severely change emission estimates, and thus climate change modeling.

As things stand, national emissions estimates conducted by the Japanese government take what is called a "bottom-up approach," where data is based on generic estimates and inventories of annual chemical use. This, he argues, is an outdated and backwards approach.

"It is apparent that there are unreported emissions," he said.

"Atmospheric scientists often say that relying solely on bottom-up inventories to tell you how greenhouse gas emissions change is like going on a diet without weighing yourself," added Steve Montzka, a research chemist with the NOAA, who was not involved in the research.

He praised Saito's work, calling it a strong example of why nations should pay more attention to halocarbons and other unconsidered emissions even as they work to help cull global influences on climate change.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

- follow Brian on Twitter @BS_ButNoBS