{"id":72093,"date":"2022-06-10T19:24:29","date_gmt":"2022-06-10T23:24:29","guid":{"rendered":"https:\/\/www.carilec.org\/?p=72093"},"modified":"2022-06-15T14:44:30","modified_gmt":"2022-06-15T18:44:30","slug":"what-is-committed-warming-a-climate-scientist-explains-why-global-warming-can-continue-long-after-emissions-end","status":"publish","type":"post","link":"https:\/\/carilec.org\/what-is-committed-warming-a-climate-scientist-explains-why-global-warming-can-continue-long-after-emissions-end\/","title":{"rendered":"What is \u2018committed warming\u2019? A climate scientist explains why global warming can continue long after emissions end"},"content":{"rendered":"<div id=\"attachment_72101\" style=\"width: 520px\" class=\"wp-caption alignleft\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-72101\" class=\"wp-image-72101\" src=\"https:\/\/cdn.carilec.org\/wp-content\/uploads\/2022\/06\/The-Conversation-Getty-Images-300x192.png\" alt=\"\" width=\"510\" height=\"327\" srcset=\"https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/The-Conversation-Getty-Images-300x192.png 300w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/The-Conversation-Getty-Images-768x491.png 768w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/The-Conversation-Getty-Images-600x384.png 600w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/The-Conversation-Getty-Images.png 866w\" sizes=\"auto, (max-width: 510px) 100vw, 510px\" \/><p id=\"caption-attachment-72101\" class=\"wp-caption-text\">Greenhouse gases emitted today will warm the planet for years. David McNew\/Getty Images<\/p><\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\">By now, few people question the reality that humans\u00a0are altering Earth\u2019s climate. The real question is: How quickly can we halt, even reverse, the damage?<\/p>\n<p style=\"text-align: justify;\">Part of the answer to this question lies in the concept of \u201ccommitted warming,\u201d also known as \u201cpipeline warming.\u201d<\/p>\n<p style=\"text-align: justify;\">It refers to future increases in global temperatures that will be caused by greenhouse gases that have already been emitted. In other words, if the clean energy transition happened overnight, how much warming would still ensue?<\/p>\n<h2 style=\"text-align: justify;\">Earth\u2019s energy budget is out of balance<\/h2>\n<p style=\"text-align: justify;\">Humans cause global warming when their activities emit greenhouse gases, which trap heat in the lower atmosphere, preventing it from escaping out to space.<\/p>\n<p style=\"text-align: justify;\">Before people began burning fossil fuels to power factories and vehicles and raising methane-emitting cattle in nearly every arable region, Earth\u2019s energy budget was roughly in balance. About the same amount of energy was coming in from the Sun as was leaving.<\/p>\n<p style=\"text-align: justify;\">Today, rising carbon dioxide concentrations in the atmosphere are\u00a0more than 50% higher\u00a0than they were at the dawn of the industrial age, and they\u2019re\u00a0trapping more of that energy.<\/p>\n<div style=\"text-align: justify;\"><\/div>\n<div style=\"text-align: justify;\">\n<p><iframe loading=\"lazy\" title=\"Earth&#039;s Delicate Energy Balance | California Academy of Sciences\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/U2CPwWgY_G4?start=231&#038;feature=oembed&amp;wmode=opaque\"  allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<\/div>\n<p style=\"text-align: justify;\">Those carbon dioxide emissions, together with other greenhouse gases such as methane, and offset by some aspects of aerosol air pollution, are trapping energy equivalent to the detonation of\u00a0five Hiroshima-style atomic bombs per second.<\/p>\n<p style=\"text-align: justify;\">With more energy coming in than leaving, Earth\u2019s thermal energy increases, raising the temperature of land, oceans and air and melting ice.<\/p>\n<h2 style=\"text-align: justify;\">Warming in the pipeline<\/h2>\n<p style=\"text-align: justify;\">The effects of tampering with Earth\u2019s energy balance take time to show up. Think of what happens when you turn the hot water faucet all the way up on a cold winter day: The pipes are full of cold water, so it takes time for the warm water to get to you \u2013 hence the term \u201cpipeline warming.\u201d The warming hasn\u2019t been felt yet, but it is in the pipeline.<\/p>\n<p style=\"text-align: justify;\">There are three major reasons Earth\u2019s climate is expected to continue warming after emissions stop.<\/p>\n<p style=\"text-align: justify;\">First, the\u00a0leading contributors\u00a0to global warming \u2013 carbon dioxide and methane \u2013 linger in the atmosphere for a long time: about 10 years on average for methane, and a whopping 400 years for carbon dioxide, with some molecules sticking around for up to millennia. So, turning off emissions doesn\u2019t translate into instant reductions in the amount of these heat-trapping gases in the atmosphere.<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-72097\" src=\"https:\/\/cdn.carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-300x198.png\" alt=\"\" width=\"650\" height=\"428\" srcset=\"https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-300x198.png 300w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-1024x675.png 1024w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-768x506.png 768w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-600x396.png 600w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table.png 1030w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/p>\n<p style=\"text-align: justify;\">Second, part of this warming has been offset by man-made emissions of another form of pollution: sulfate aerosols, tiny particles emitted by fossil fuel burning, that reflect sunlight out to space. Over the past century, this\u00a0global dimming\u00a0has been\u00a0masking the warming effect\u00a0of greenhouse emissions. But these and other man-made aerosols also harm\u00a0human health\u00a0and\u00a0the biosphere. Removing those and short-lived greenhouse gases translates to\u00a0a few tenths of a degree\u00a0of additional warming over about a decade, before reaching a new equilibrium.<\/p>\n<p style=\"text-align: justify;\">Finally, Earth\u2019s climate takes time to adjust to any change in energy balance. About two-thirds of Earth\u2019s surface is made of water, sometimes very deep water, which is slow to take up the excess carbon and heat. So far,\u00a0over 91% of the heat added by human activities, and\u00a0about a quarter of the excess carbon, have gone into the oceans. While land-dwellers may be grateful for this buffer, the extra heat contributes to sea level rise through\u00a0thermal expansion\u00a0and also\u00a0marine heat waves, while the extra carbon makes the ocean more corrosive to many shelled organisms, which can disrupt the ocean food chain.<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-72099\" src=\"https:\/\/cdn.carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-2-300x179.png\" alt=\"\" width=\"650\" height=\"388\" srcset=\"https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-2-300x179.png 300w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-2-1024x611.png 1024w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-2-768x458.png 768w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-2-600x358.png 600w, https:\/\/carilec.org\/wp-content\/uploads\/2022\/06\/Capture-Table-2.png 1055w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/p>\n<p style=\"text-align: justify;\">Earth\u2019s surface temperature, driven by the imbalance of radiant energy at the top of the atmosphere, and modulated by the enormous thermal inertia of its oceans, is still playing catch up with its\u00a0biggest control knob: carbon dioxide concentration.<\/p>\n<h2 style=\"text-align: justify;\">How much warming?<\/h2>\n<p style=\"text-align: justify;\">So, how much committed warming are we in for? There isn\u2019t a clear answer.<\/p>\n<p style=\"text-align: justify;\">The world has\u00a0already warmed more than 1.1 degrees Celsius (2 F) compared to pre-industrial levels. Nations worldwide agreed in 2015 to try to prevent the global average from rising more than 1.5\u00b0C (2.7 F) to limit the damage, but\u00a0the world has been slow to react.<\/p>\n<p style=\"text-align: justify;\">Determining the amount of warming ahead is complicated. Several\u00a0recent studies\u00a0use climate models to estimate future warming. A\u00a0study of 18 Earth system models\u00a0found that when emissions were cut off, some continued warming for decades to hundreds of years, while others began cooling quickly. Another study, published in June 2022, found a\u00a042% chance that the world is already committed to 1.5 degrees.<\/p>\n<p style=\"text-align: justify;\">The amount of warming matters because the dangerous consequences of global warming don\u2019t simply rise in proportion to global temperature; they typically increase exponentially, particularly for\u00a0food production\u00a0at risk from heat, drought and storms.<\/p>\n<p style=\"text-align: justify;\">Further, Earth has\u00a0tipping points\u00a0that could trigger irreversible changes to fragile parts of the Earth system, like glaciers or ecosystems. We won\u2019t necessarily know right away when the planet has passed a tipping point, because those changes are often slow to show up. This and other climate-sensitive systems are the basis for the precautionary principle of limiting warming under 2\u00b0C (3.6 F), and preferably, 1.5\u00b0C.<\/p>\n<p style=\"text-align: justify;\">The heart of the climate problem, embedded in this idea of committed warming, is that there are long delays between changes in human behavior and changes in the climate. While the precise amount of committed warming is still a matter of some contention, evidence shows the safest route forward is to urgently transition to a carbon-free,\u00a0more equitable\u00a0economy that generates far less greenhouse gas emissions.<\/p>\n<p style=\"text-align: justify;\"><strong><em>This article is republished from\u00a0<a class=\"link \" href=\"http:\/\/theconversation.com\/?utm_source=Yahoo&amp;utm_medium=related-link&amp;utm_campaign=related-link-0&amp;utm_content=article-184374\" target=\"_blank\" rel=\"nofollow noopener\" data-ylk=\"slk:The Conversation\" data-rapid_p=\"32\" data-v9y=\"1\">The Conversation<\/a>, a nonprofit news site dedicated to sharing ideas from academic experts. It was written by:\u00a0<a class=\"link \" href=\"https:\/\/theconversation.com\/profiles\/julien-emile-geay-1351305?utm_source=Yahoo&amp;utm_medium=related-link&amp;utm_campaign=byline-link&amp;utm_content=article-184374\" target=\"_blank\" rel=\"nofollow noopener\" data-ylk=\"slk:Julien Emile-Geay\" data-rapid_p=\"33\" data-v9y=\"1\">Julien Emile-Geay<\/a>,\u00a0<a class=\"link \" href=\"https:\/\/theconversation.com\/institutions\/usc-dornsife-college-of-letters-arts-and-sciences-2669?utm_source=Yahoo&amp;utm_medium=related-link&amp;utm_campaign=byline-link&amp;utm_content=article-184374\" target=\"_blank\" rel=\"nofollow noopener\" data-ylk=\"slk:USC Dornsife College of Letters, Arts and Sciences\" data-rapid_p=\"34\" data-v9y=\"1\">USC Dornsife College of Letters, Arts and Sciences<\/a>.<\/em><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; By now, few people question the reality that humans\u00a0are altering [&hellip;]<\/p>\n","protected":false},"author":165,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3192,16],"tags":[3676,4529,4100,1324,3419],"class_list":["post-72093","post","type-post","status-publish","format-standard","hentry","category-cdap-disaster-bulletin","category-news","tag-carbon","tag-committed-warming","tag-ecosystems","tag-energy","tag-global-warming"],"acf":[],"aioseo_notices":[],"featured_image":"https:\/\/carilec.org\/wp-includes\/images\/media\/default.svg","month_date":"Jun","day_date":"10","_links":{"self":[{"href":"https:\/\/carilec.org\/api\/wp\/v2\/posts\/72093","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carilec.org\/api\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/carilec.org\/api\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/carilec.org\/api\/wp\/v2\/users\/165"}],"replies":[{"embeddable":true,"href":"https:\/\/carilec.org\/api\/wp\/v2\/comments?post=72093"}],"version-history":[{"count":0,"href":"https:\/\/carilec.org\/api\/wp\/v2\/posts\/72093\/revisions"}],"wp:attachment":[{"href":"https:\/\/carilec.org\/api\/wp\/v2\/media?parent=72093"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/carilec.org\/api\/wp\/v2\/categories?post=72093"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/carilec.org\/api\/wp\/v2\/tags?post=72093"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}