{"id":694,"date":"2021-03-01T21:56:36","date_gmt":"2021-03-02T02:56:36","guid":{"rendered":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/?p=694"},"modified":"2021-03-01T21:57:18","modified_gmt":"2021-03-02T02:57:18","slug":"ozone-success-story","status":"publish","type":"post","link":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/es-eos\/ozone-success-story\/","title":{"rendered":"An Ozone Success Story"},"content":{"rendered":"

As a child, news of the hole in the ozone layer terrified me. I pictured green aliens covered in slime sliding through the dark hole into the skies above us, casting murky shadows over entire continents. Standing below the ozone hole I wanted to know could you see their tentacles reach through the clouds?\u00a0 I was convinced the ozone hole was a portal to a frightening and unknown world.\u00a0<\/span><\/p>\n

The stratospheric ozone layer, <\/span>15-35<\/span><\/a> km above us, acts like sunscreen. Ozone refers to O<\/span>3<\/span> gas \u2013 three oxygen atoms bonded together. The layer protects our (and every other living thing\u2019s) DNA from harmful levels of ultraviolet (UV) light from the sun that pelt our planet. Here\u2019s the catch: ultraviolet light also kickstarts chemical reactions in our atmosphere that cause oxygen atoms to break off from ozone. This leaves ozone continually crumbling and combining in a balanced cycle that maintains the layer\u2019s UV repellency. In the 1980s, however, a geophysicist and two <\/span>meteorologists<\/span><\/a> began noticing that the ozone layer was thinning each spring, particularly over Antarctica.\u00a0<\/span><\/p>\n

Thus, the ozone \u201chole\u201d was discovered. Here\u2019s what the scientists concluded. The thinning ozone layer represented a history of accumulating aerosols and\u00a0<\/span>chlorofluorocarbons\u00a0<\/span><\/i>\u2013 a kind of gas known as CFCs. At the time, CFCs were used as refrigerants in air-conditioners and cars, as cleaning products, and as foaming agents for insulation. Even hairspray aerosol cans contained CFCs. One ingredient in CFCs is <\/span>chlorine<\/span><\/a> which, as a gas, erodes away the ozone layer faster than it can be created. As gaseous CFCs accumulated in the upper atmosphere, the ozone layer was gradually eaten away and higher levels of ultraviolet light began to be recorded in the Southern Hemisphere. These findings mobilized scientists to act.\u00a0<\/span><\/p>\n

The Montreal Protocol from 1987 is one of a few examples of multinational cooperation on environmental regulations. The treaty banned production and international trade in a number of ozone-depleting substances, CFCs included. As the only UN Treaty in history to receive universal <\/span>ratification<\/span><\/a>, the signatories collaborated around a common objective to protect the ozone layer and the animals and plants who live beneath it. The ozone hole contributed to an awareness of the capacity of human behavior to mangle natural processes.\u00a0<\/span><\/p>\n

This story does not end in 1987. In 2013, the decline of CFCs unexpectedly slowed from 0.85% between 2002-2012 to 0.4% after <\/span>2013<\/span><\/a>. This was a sign that newly produced CFCs — <\/span>13,000 tons<\/span><\/a>, to be precise — were entering the atmosphere, and scientists didn\u2019t know where it was coming from. That might not sound like that much \u2013 given that in 2019 the US alone emitted 5.1 billion tons of <\/span>CO<\/span>2<\/span><\/a> \u2013 but any new CFC production contributes to a <\/span>reservoir<\/span><\/a> of CFCs that still exists in discarded items, like refrigerators and air conditioners. That pool hasn\u2019t been released yet, but its effect on the atmosphere has been accounted for. These newly produced CFCs contribute to a 6-45% increase in the global reservoir and future cumulative <\/span>emissions<\/span><\/a>. We might see aliens yet.\u00a0<\/span><\/p>\n

Eventually the CFCs were traced to eastern mainland China through <\/span>monitoring stations<\/span><\/a> in <\/span>Japan and Korea<\/span><\/a>. The Chinese government questioned the source of the emissions but agreed that improved atmospheric monitoring was <\/span>needed<\/span><\/a>. China, as a signatory of the Montreal Protocol, was <\/span>obligated<\/span><\/a> to take action in the face of these findings and they did just that. Their atmospheric testing stations now record CFC levels in the atmosphere, labs were built to test for CFCs in suspect consumer <\/span>products<\/span><\/a>, and hefty <\/span>fines<\/span><\/a> were placed on any factories producing CFCs.\u00a0<\/span><\/p>\n

Like so many emissions, the effects of CFCs aren\u2019t limited to the current moment but to many years in the future. That being said, the Montreal Protocol worked. The damage to the ozone layer will be <\/span>negligible<\/span><\/a> and China took firm action. We can apply our sunscreen peacefully knowing the thinned ozone layer is still on track to recover fully with no aliens in sight.\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

As a child, news of the hole in the ozone layer terrified me. I pictured green aliens covered in slime sliding through the dark hole into the skies above us, casting murky shadows over entire continents. Standing below the ozone hole I wanted to know could you see their tentacles reach through the clouds?\u00a0 I […]<\/p>\n","protected":false},"author":90,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[66],"tags":[72,71,70],"class_list":{"0":"post-694","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-es-eos","7":"tag-chlorofluorocarbons","8":"tag-montreal-protocol","9":"tag-ozone-hole","10":"entry"},"featured_image_src":null,"featured_image_src_square":null,"author_info":{"display_name":"Nora Jackson '21","author_link":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/author\/njackson\/"},"_links":{"self":[{"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/posts\/694","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/users\/90"}],"replies":[{"embeddable":true,"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/comments?post=694"}],"version-history":[{"count":0,"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/posts\/694\/revisions"}],"wp:attachment":[{"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/media?parent=694"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/categories?post=694"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/students.bowdoin.edu\/bowdoin-science-journal\/wp-json\/wp\/v2\/tags?post=694"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}