{"id":157819,"date":"2014-09-24T12:48:14","date_gmt":"2014-09-24T15:48:14","guid":{"rendered":"http:\/\/revistapesquisa.fapesp.br\/?p=157819"},"modified":"2014-10-24T12:54:58","modified_gmt":"2014-10-24T14:54:58","slug":"persistent-destruction","status":"publish","type":"post","link":"https:\/\/revistapesquisa.fapesp.br\/en\/persistent-destruction\/","title":{"rendered":"Persistent destruction"},"content":{"rendered":"<div id=\"attachment_157821\" style=\"max-width: 300px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-157821\" src=\"http:\/\/revistapesquisa.fapesp.br\/wp-content\/uploads\/2014\/10\/Tecno_ozone.jpg\" alt=\"Ozone layer (in blue): still under attack by carbon tetrachloride\" width=\"290\" height=\"290\" srcset=\"https:\/\/revistapesquisa.fapesp.br\/wp-content\/uploads\/2014\/10\/Tecno_ozone.jpg 290w, https:\/\/revistapesquisa.fapesp.br\/wp-content\/uploads\/2014\/10\/Tecno_ozone-120x120.jpg 120w, https:\/\/revistapesquisa.fapesp.br\/wp-content\/uploads\/2014\/10\/Tecno_ozone-250x250.jpg 250w\" sizes=\"auto, (max-width: 290px) 100vw, 290px\" \/><p class=\"wp-caption-text\"><span class=\"media-credits-inline\">NASA<\/span>Ozone layer (<em>in blue<\/em>): still under attack by carbon tetrachloride<span class=\"media-credits\">NASA<\/span><\/p><\/div>\n<p>It was thought that the substances that destroy the ozone layer \u2013 which filters the sun&#8217;s incoming ultraviolet rays and thus prevents their damaging effects, including skin cancer \u2013 had stopped being emitted for good, as determined by the international agreement signed in 1987 and known as the Montreal Protocol. Apparently, that is not the case. A team of NASA researchers has discovered that the Earth&#8217;s atmosphere contains an elevated amount of carbon tetrachloride (CCl<sub>4<\/sub>), one of the substances known to deplete the ozone layer. More specifically, the estimated CCl<sub>4<\/sub> emissions calculated by means of computational mathematical models is 43,000 metric tons per year, or 30% of the highest rates of CCl<sub>4<\/sub> emission before the global ban on the substance (<em><i>Geophysical Research Letters<\/i><\/em>, August 18, 2014). This CCl<sub>4<\/sub>, which was used extensively in refrigerators and air conditioning units before the Montreal Protocol, is probably now coming from industrial leaks, contaminated sites, or unknown sources \u2013 in other words, its origin remains unclear. The experts at NASA concluded that if CCl<sub>4<\/sub> emissions between 2007 and 2012 had indeed been zero as reported, the concentration of this compound in the atmosphere should have dropped by 4% per year. However, the actual observed reduction was a much more modest 1%. By running simulations of the globe&#8217;s atmospheric chemistry, the researchers \u2013 now aiming to identify the source of the unexplained emissions \u2013 also concluded that CCl<sub>4<\/sub> may linger in the atmosphere 40% longer than expected.<\/p>\n","protected":false},"excerpt":{"rendered":"Forbidden substance still destroys ozone layer","protected":false},"author":475,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[168],"tags":[259,200],"coauthors":[785],"class_list":["post-157819","post","type-post","status-publish","format-standard","hentry","category-technoscience","tag-chemistry","tag-environment"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/157819","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/475"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=157819"}],"version-history":[{"count":0,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/157819\/revisions"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=157819"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=157819"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=157819"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=157819"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}