[ad_1]
A new study reveals that ozone depleting compounds are still used in China, even though the Montreal Protocol banned them worldwide.
Eastern China has released significant amounts of this substance, called carbon tetrachloride. (CCl4) – known to destroy ozone, protective layer of the earth 's atmosphere that protects the world from dangerous ultraviolet rays.
This new research is another piece of evidence showing that China is at the origin of ozone. -reducing emissions. Last summer, a New York Times investigation also revealed that factories in the country were releasing banned substances that were destroying the ozone layer. [Earth from Above: 101 Stunning Images from Orbit]
Ozone is located very high in the Earth's stratosphere, about 10 km from the ground, where it absorbs much of the sun's ultraviolet (UV) rays. This radiation increases the risk of cancer and eye damage in humans. An artificial hole already exists in the ozone layer over Antarctica. Thus, to protect ozone, all the countries of the world have collectively agreed to ban substances that destroy this layer, including the CC14, banned worldwide during the update of the Montreal Protocol in 2010. Despite this agreement, about 44 000 tonnes (40 000) Recent studies have shown that mysterious tonnes are emitted each year.
An international team of Australian, South Korean, Swiss, British and British scientists investigated the origin of these mysteries. shows. The team used data from atmospheric and ground – based atmospheric concentration sensors from the Korean peninsula, as well as two models simulating the flow of gases into the atmosphere.
These techniques have borne fruit; The researchers found that about half of these mystifying emissions came from East China between 2009 and 2016.
"Our results show that carbon tetrachloride emissions from the region of & # 39, East Asia account for a significant share of global emissions, "said study author Mark Lunt, research badociate in chemistry at Bristol University in England, said in a statement. "And [these emissions] are significantly larger than some previous studies suggested."
CCl4 emissions are so significant that "despite the phasing out of emissive carbon tetrachloride production in 2010, we found no evidence of a subsequent reduction in these emissions. emissions. "said Lunt. Some regions, including China's Shandong Province after 2012, have even pumped more emissions than before, he said.
However, scientists said that they did not know where the other CCl4 emissions came from. It is possible that large quantities of this gas are inadvertently created when other chemicals, such as chlorine, are produced, said the researchers.
"Our work shows the location of carbon tetrachloride emissions," said Matt Rigby, co-author of the study. atmospheric chemistry reader at the University of Bristol, said in the statement. "However, we do not yet know which processes or industries are responsible, which is important because we do not know if it is produced intentionally or inadvertently."
Further atmospheric research could reveal other culprits. "There are parts of the world – such as India, South America, and other parts of Asia" where ozone-depleting gases emit may be in progress, but detailed atmospheric measurements are lacking, "said Rigby.
helping scientists and regulators identify exactly where and why these emissions occur in China .After all, the earlier these emissions will be stopped, more quickly the ozone will recover, said the researchers.
"It is tempting to consider the depletion of the ozone layer as a problem solved," said Lunt. "But the monitoring of gases of human origin that deplete the ozone layer in the atmosphere is essential to ensure the continued success of phasing out these compounds. "
L & # 39; study was published online September 28 in the journal Geophysical Research Let ters. [19659002] Originally published on Live Science.
[ad_2]
Source link
