<!DOCTYPE html><html lang="en-US" xmlns:fb="https://www.facebook.com/2008/fbml" xmlns:addthis="https://www.addthis.com/help/api-spec" prefix="og: http://ogp.me/ns#"><head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"> <meta name="mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-capable" content="yes"> <meta name="apple-mobile-web-app-title" content="FactCheck.org - A Project of The Annenberg Public Policy Center"> <link href="https://fonts.googleapis.com/css?family=Merriweather|Barlow+Semi+Condensed:500" rel="stylesheet"> <link rel="profile" href="https://gmpg.org/xfn/11"> <link rel="pingback" href="https://www.factcheck.org/xmlrpc.php"> <link rel="apple-touch-icon" sizes="57x57" href="/apple-icon-57x57.png"> <link rel="apple-touch-icon" sizes="60x60" href="/apple-icon-60x60.png"> <link rel="apple-touch-icon" sizes="72x72" href="/apple-icon-72x72.png"> <link rel="apple-touch-icon" sizes="76x76" href="/apple-icon-76x76.png"> <link rel="apple-touch-icon" sizes="114x114" href="/apple-icon-114x114.png"> <link rel="apple-touch-icon" sizes="120x120" href="/apple-icon-120x120.png"> <link rel="apple-touch-icon" sizes="144x144" href="/apple-icon-144x144.png"> <link rel="apple-touch-icon" sizes="152x152" href="/apple-icon-152x152.png"> <link rel="apple-touch-icon" sizes="180x180" href="/apple-icon-180x180.png"> <link rel="icon" type="image/png" sizes="192x192" href="/android-icon-192x192.png"> <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="96x96" href="/favicon-96x96.png"> <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png"> <link rel="manifest" href="/manifest.json"> <meta name="msapplication-TileColor" content="#ffffff"> <meta name="msapplication-TileImage" content="/ms-icon-144x144.png"> <meta name="theme-color" content="#ffffff"> <script async src="//dhpikd1t89arn.cloudfront.net/js/include/sharethefacts-v1.js"></script> <title>Hurricane Harvey and Climate Change - FactCheck.org</title><link rel="canonical" href="https://www.factcheck.org/2017/08/hurricane-harvey-climate-change/"/><meta property="og:locale" content="en_US"/><meta property="og:type" content="article"/><meta property="og:title" content="Hurricane Harvey and Climate Change - FactCheck.org"/><meta property="og:description" content="Hurricane Harvey has brought with it both a record amount of rain and questions about how much climate change can be blamed for the storm. Climate change did not cause Harvey, or any other storm, but it makes intense storms like Harvey more likely to occur, scientists say."/><meta property="og:url" content="https://www.factcheck.org/2017/08/hurricane-harvey-climate-change/"/><meta property="og:site_name" content="FactCheck.org"/><meta property="article:publisher" content="https://www.facebook.com/factcheck.org"/><meta property="article:section" content="SciCheck"/><meta property="article:published_time" content="2017-08-30T17:36:18+00:00"/><meta property="article:modified_time" content="2017-11-14T14:46:48+00:00"/><meta property="og:updated_time" content="2017-11-14T14:46:48+00:00"/><meta property="og:image" content="https://cdn.factcheck.org/UploadedFiles/cold-front-63037_1920.jpg"/><meta property="og:image:secure_url" content="https://cdn.factcheck.org/UploadedFiles/cold-front-63037_1920.jpg"/><meta property="og:image:width" content="720"/><meta property="og:image:height" content="307"/><meta name="twitter:card" content="summary_large_image"/><meta name="twitter:description" content="Hurricane Harvey has brought with it both a record amount of rain and questions about how much climate change can be blamed for the storm. Climate change did not cause Harvey, or any other storm, but it makes intense storms like Harvey more likely to occur, scientists say."/><meta name="twitter:title" content="Hurricane Harvey and Climate Change - FactCheck.org"/><meta name="twitter:site" content="@factcheckdotorg"/><meta name="twitter:image" content="https://cdn.factcheck.org/UploadedFiles/cold-front-63037_1920.jpg"/><meta name="twitter:creator" content="@factcheckdotorg"/><script type='application/ld+json'>{"@context":"http:\/\/schema.org","@type":"WebSite","@id":"#website","url":"https:\/\/www.factcheck.org\/","name":"FactCheck.org","potentialAction":{"@type":"SearchAction","target":"https:\/\/www.factcheck.org\/?s={search_term_string}","query-input":"required name=search_term_string"}}</script><script type='application/ld+json'>{"@context":"http:\/\/schema.org","@type":"Organization","url":"https:\/\/www.factcheck.org\/2017\/08\/hurricane-harvey-climate-change\/","sameAs":["https:\/\/www.facebook.com\/factcheck.org","https:\/\/twitter.com\/factcheckdotorg"],"@id":"#organization","name":"FactCheck.org","logo":"https:\/\/www.factcheck.org\/UploadedFiles\/2013\/04\/TransparentWebLogo.png"}</script><link rel='dns-prefetch' href='//s7.addthis.com'/><link rel='dns-prefetch' href='//code.jquery.com'/><link rel='dns-prefetch' href='//s.w.org'/><link rel='dns-prefetch' href='//cdn.factcheck.org'/><link rel='dns-prefetch' href='//platform.twitter.com'/><link rel='dns-prefetch' href='//factcheck.sharethefacts.co'/><link rel="alternate" type="application/rss+xml" title="FactCheck.org &raquo; Feed" href="https://www.factcheck.org/feed/"/><link rel='stylesheet' id='child-understrap-styles-css' href='https://www.factcheck.org/wp-content/themes/factcheckstrap/css/child-theme.min.css?ver=567df1931476fe3d8d7d3feecf09702d' type='text/css' media='all'/><link rel='stylesheet' id='addthis_all_pages-css' href='https://cdn.factcheck.org/wp-content/plugins/addthis/frontend/build/addthis_wordpress_public.min.css?ver=567df1931476fe3d8d7d3feecf09702d' type='text/css' media='all'/><script type='text/javascript' src='https://cdn.factcheck.org/wp-content/themes/understrap/js/popper.min.js?ver=567df1931476fe3d8d7d3feecf09702d'></script><link rel='https://api.w.org/' href='https://www.factcheck.org/wp-json/'/><link rel="EditURI" type="application/rsd+xml" title="RSD" href="https://www.factcheck.org/xmlrpc.php?rsd"/><link rel="wlwmanifest" type="application/wlwmanifest+xml" href="https://www.factcheck.org/wp-includes/wlwmanifest.xml"/> <link rel='shortlink' href='https://www.factcheck.org/?p=129078'/><link rel="alternate" type="application/json+oembed" href="https://www.factcheck.org/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.factcheck.org%2F2017%2F08%2Fhurricane-harvey-climate-change%2F"/><link rel="alternate" type="text/xml+oembed" href="https://www.factcheck.org/wp-json/oembed/1.0/embed?url=https%3A%2F%2Fwww.factcheck.org%2F2017%2F08%2Fhurricane-harvey-climate-change%2F&#038;format=xml"/><style type="text/css">.broken_link, a.broken_link { text-decoration: line-through;}</style><script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
	(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
	m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
  ga('create', 'UA-22460056-1', 'auto');
  ga('send', 'pageview');
</script></head><body class="post-template-default single single-post postid-129078 single-format-standard group-blog"> <svg xmlns="http://www.w3.org/2000/svg" style="display: none;" viewBox="0 0 136.9 108.9"> <symbol id="factcheck-logo" viewBox="0 0 136.9 108.9" > <path class="fc-blue" d="M137 29.2H0V109h137zm-7 72.8H7v-.3a107.2 107.2 0 0 1 30.3-17.3C60 76.2 70.6 77 70.6 77s.3-4.8-2.4-13c-1.6-4.4-4-10-9.5-19l-23 35.8L7 67.2V41.4L30 55l27.3-25.8H69l-4.6 7H130z"/><path class="fc-red" d="M62 40l2.4-4H130v5.4s-9.4 3-13.8 4S104 48 96.6 48l-29 .2a30.5 30.5 0 0 0-2.6-4.6 36.2 36.2 0 0 0-3-3.7zm12 21.6l16.8-.4a149 149 0 0 0 24-3.3l15.2-5v14s-4 1.7-7 2.6c-4 1.4-14.5 3.2-18 3.6l-26.5 3s-1-4.6-1.8-7.5-2.5-7-2.5-7zM96.5 102h-57s8.3-4 14.2-6.2a220.3 220.3 0 0 1 26-7.3c6-1 17-2.7 24.7-3.4s25.6-5 25.6-5v14l-11.3 3-22 5z"/><path class="fc-blue" d="M87.8 0L57.4 29.2H69L88 0"/> </symbol> </svg><div class="hfeed site" id="page">  <div class="container container-branding container-branding-xl"> <div class="row"> <div class="col-7 col-xl-9"> <a aria-label="FactCheck.org" rel="home" href="https://www.factcheck.org/" class="logo"> <svg class="d-none d-md-inline-flex d-lg-inline-flex d-xl-inline-flex"> <use xlink:href="#factcheck-logo"> </svg> <!--[if lt IE 9]> <img src="/img/logomark.png" alt="FactCheck.org"> <![endif]--> <span class="logotype"> FactCheck<span class="text-fc-red">.org</span><sup>&reg;</sup> </span> </a> <span class="appc-credit">A Project of The Annenberg Public Policy Center</span> </div> <div class="d-none d-md-inline col-5 col-xl-3"> <div class="fc-social-media-header"> <div class="fc-social-media-header-icon"> <a href="https://www.facebook.com/factcheck.org"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-facebook-mini.png" alt="Become a Facebook fan"> </a> </div> <div class="fc-social-media-header-icon"> <a href="https://www.twitter.com/factcheckdotorg"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-twitter.png" alt="Follow us on Twitter"> </a> </div> <div class="fc-social-media-header-icon"> <a href="https://www.factcheck.org/feed/"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-rss.png" alt="Get the RSS feed"> </a> </div> <div class="fc-social-media-header-icon"> <a href="http://factcheckdotorg.tumblr.com/"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-tumblr.png" alt="Follow us on Tumblr"> </a> </div> <div class="fc-social-media-header-icon"> <a href="https://www.factcheck.org/subscribe/"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-email.png" alt="Sign up for the email newsletter"> </a> </div> <div class="fc-social-media-header-icon"> <a href="https://giving.aws.cloud.upenn.edu/?fastStart=simpleForm&#038;program=ANS&#038;fund=602014"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-donate.png" alt="Help us hold politicians accountable. "> </a> </div> </div> </div> </div> </div> <div class="wrapper-fluid wrapper-navbar" id="wrapper-navbar"> <a class="skip-link screen-reader-text sr-only" href="#content">Skip to content</a> <nav class="navbar navbar-expand-md navbar-light bg-light"> <div class="container"> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <a aria-label="FactCheck.org" rel="home" href="https://www.factcheck.org/" class="logo logo-xs"> <span class="logotype"> FactCheck<span class="text-fc-red">.org</span><sup>&reg;</sup> </span> </a>  <div id="navbarNavDropdown" class="collapse navbar-collapse"><ul id="main-menu" class="navbar-nav"><li id="menu-item-75121" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-home nav-item menu-item-75121"><a title="Home" href="https://www.factcheck.org" class="nav-link">Home</a></li><li id="menu-item-75124" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children nav-item menu-item-75124 dropdown"><a title="Articles" href="#" data-toggle="dropdown" class="nav-link dropdown-toggle">Articles <span class="caret"></span></a><ul class=" dropdown-menu" role="menu"> <li id="menu-item-46782" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-46782"><a title="Featured" href="https://www.factcheck.org/articles/" class="nav-link">Featured</a></li> <li id="menu-item-46900" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-46900"><a title="The Wire" href="https://www.factcheck.org/the-factcheck-wire/" class="nav-link">The Wire</a></li> <li id="menu-item-121568" class="menu-item menu-item-type-taxonomy menu-item-object-category current-post-ancestor current-menu-parent current-post-parent nav-item menu-item-121568"><a title="SciCheck" href="https://www.factcheck.org/scicheck/" class="nav-link">SciCheck</a></li></ul></li><li id="menu-item-121564" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children nav-item menu-item-121564 dropdown"><a title="Ask a Question" href="#" data-toggle="dropdown" class="nav-link dropdown-toggle">Ask a Question <span class="caret"></span></a><ul class=" dropdown-menu" role="menu"> <li id="menu-item-75166" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-75166"><a title="Ask FactCheck" href="https://www.factcheck.org/askfactcheck/" class="nav-link">Ask FactCheck</a></li> <li id="menu-item-121565" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-121565"><a title="Ask SciCheck" href="https://www.factcheck.org/askscicheck/" class="nav-link">Ask SciCheck</a></li></ul></li><li id="menu-item-46786" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-46786"><a title="Viral Spiral" href="https://www.factcheck.org/hot-topics/" class="nav-link">Viral Spiral</a></li><li id="menu-item-75144" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children nav-item menu-item-75144 dropdown"><a title="Archives" href="#" data-toggle="dropdown" class="nav-link dropdown-toggle">Archives <span class="caret"></span></a><ul class=" dropdown-menu" role="menu"> <li id="menu-item-118869" class="menu-item menu-item-type-taxonomy menu-item-object-person nav-item menu-item-118869"><a title="President Trump" href="https://www.factcheck.org/person/donald-trump/" class="nav-link">President Trump</a></li> <li id="menu-item-100503" class="menu-item menu-item-type-taxonomy menu-item-object-person nav-item menu-item-100503"><a title="Paul Ryan" href="https://www.factcheck.org/person/paul-ryan/" class="nav-link">Paul Ryan</a></li> <li id="menu-item-82664" class="menu-item menu-item-type-taxonomy menu-item-object-person nav-item menu-item-82664"><a title="Mitch McConnell" href="https://www.factcheck.org/person/mitch-mcconnell/" class="nav-link">Mitch McConnell</a></li> <li id="menu-item-118179" class="menu-item menu-item-type-taxonomy menu-item-object-person nav-item menu-item-118179"><a title="Chuck Schumer" href="https://www.factcheck.org/person/chuck-schumer/" class="nav-link">Chuck Schumer</a></li> <li id="menu-item-118180" class="menu-item menu-item-type-taxonomy menu-item-object-person nav-item menu-item-118180"><a title="Nancy Pelosi" href="https://www.factcheck.org/person/nancy-pelosi/" class="nav-link">Nancy Pelosi</a></li> <li id="menu-item-118865" class="menu-item menu-item-type-taxonomy menu-item-object-issue nav-item menu-item-118865"><a title="jobs" href="https://www.factcheck.org/issue/jobs/" class="nav-link">jobs</a></li> <li id="menu-item-82666" class="menu-item menu-item-type-taxonomy menu-item-object-issue nav-item menu-item-82666"><a title="health care" href="https://www.factcheck.org/issue/health-care/" class="nav-link">health care</a></li> <li id="menu-item-101750" class="menu-item menu-item-type-taxonomy menu-item-object-issue nav-item menu-item-101750"><a title="climate change" href="https://www.factcheck.org/issue/climate-change/" class="nav-link">climate change</a></li> <li id="menu-item-86805" class="menu-item menu-item-type-taxonomy menu-item-object-issue nav-item menu-item-86805"><a title="immigration" href="https://www.factcheck.org/issue/immigration/" class="nav-link">immigration</a></li> <li id="menu-item-46906" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-46906"><a title="View All" href="https://www.factcheck.org/archives/" class="nav-link">View All</a></li></ul></li><li id="menu-item-75727" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children nav-item menu-item-75727 dropdown"><a title="About Us" href="#" data-toggle="dropdown" class="nav-link dropdown-toggle">About Us <span class="caret"></span></a><ul class=" dropdown-menu" role="menu"> <li id="menu-item-75731" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-75731"><a title="Our Mission" href="https://www.factcheck.org/about/our-mission/" class="nav-link">Our Mission</a></li> <li id="menu-item-117787" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-117787"><a title="Our Process" href="https://www.factcheck.org/our-process/" class="nav-link">Our Process</a></li> <li id="menu-item-75730" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-75730"><a title="Our Funding" href="https://www.factcheck.org/our-funding/" class="nav-link">Our Funding</a></li> <li id="menu-item-75728" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-75728"><a title="Our Staff" href="https://www.factcheck.org/our-staff/" class="nav-link">Our Staff</a></li> <li id="menu-item-103776" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-103776"><a title="Undergraduate Fellows" href="https://www.factcheck.org/undergraduate-fellows/" class="nav-link">Undergraduate Fellows</a></li> <li id="menu-item-76678" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-76678"><a title="Awards" href="https://www.factcheck.org/awards/" class="nav-link">Awards</a></li> <li id="menu-item-75729" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-75729"><a title="Contact Us" href="https://www.factcheck.org/about/contact-us/" class="nav-link">Contact Us</a></li></ul></li><li id="menu-item-75130" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-75130"><a title="Search" href="https://www.factcheck.org/search/" class="nav-link">Search</a></li><li id="menu-item-75125" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-has-children nav-item menu-item-75125 dropdown"><a title="More" href="#" data-toggle="dropdown" class="nav-link dropdown-toggle">More <span class="caret"></span></a><ul class=" dropdown-menu" role="menu"> <li id="menu-item-125157" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-125157"><a title="Debunking False Stories" href="https://www.factcheck.org/fake-news/" class="nav-link">Debunking False Stories</a></li> <li id="menu-item-75126" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-75126"><a title="FactCheck On the Air" href="https://www.factcheck.org/on-the-air/" class="nav-link">FactCheck On the Air</a></li> <li id="menu-item-75127" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-75127"><a title="Party Lines" href="https://www.factcheck.org/party-lines/" class="nav-link">Party Lines</a></li> <li id="menu-item-46908" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-46908"><a title="Mailbag" href="https://www.factcheck.org/factcheck-mailbag/" class="nav-link">Mailbag</a></li> <li id="menu-item-75129" class="menu-item menu-item-type-taxonomy menu-item-object-category nav-item menu-item-75129"><a title="Quiz Archive" href="https://www.factcheck.org/quiz-archive/" class="nav-link">Quiz Archive</a></li> <li id="menu-item-134164" class="menu-item menu-item-type-post_type menu-item-object-page nav-item menu-item-134164"><a title="2016 Elections" href="https://www.factcheck.org/2016-elections/" class="nav-link">2016 Elections</a></li></ul></li></ul></div> </div> </nav> </div><div class="wrapper" id="single-wrapper"> <div class="container" id="content" tabindex="-1"> <header class="entry-header"> <div class="breadcrumb-category"><a href="https://www.factcheck.org/scicheck/" title="FactCheck.org&#039;s SciCheck feature focuses exclusively on false and misleading scientific claims that are made by partisans to influence public policy. It was launched in January 2015 with a grant from the Stanton Foundation. The foundation was founded by the late Frank Stanton, president of CBS for 25 years, from 1946 to 1971.">SciCheck</a> &#8250; <a href="https://www.factcheck.org/the-factcheck-wire/" >The Wire</a></div> <h1 class="entry-title">Hurricane Harvey and Climate Change</h1> <div class="entry-meta"> <p class="byline"> By <a href="https://www.factcheck.org/author/vanessa-schipani/" title="Posts by Vanessa Schipani" class="author url fn" rel="author">Vanessa Schipani</a></p><p class="posted-on">Posted on <time class="entry-date published updated" datetime="2017-08-30T17:36:18+00:00">August 30, 2017</time></p> </div> </header> <hr> <div class="row">  <div class="col-lg-8 content-area" id="primary"> <main class="site-main" id="main"> <article class="post-129078 post type-post status-publish format-standard has-post-thumbnail hentry category-scicheck category-the-factcheck-wire location-international location-national issue-climate-change issue-extreme-weather-2 issue-global-warming issue-hurricane-harvey" id="post-129078"> <div class="entry-content"> <div class="at-above-post addthis_tool" data-url="https://www.factcheck.org/2017/08/hurricane-harvey-climate-change/"></div><p>Hurricane Harvey has brought with it both a record amount of rain and questions about how much climate change can be blamed for the storm. Climate change did not cause Harvey, or any other storm, but it makes intense storms like Harvey more likely to occur, scientists say.</p><p><img class="alignleft size-full wp-image-107984" src="https://www.factcheck.org/UploadedFiles/2016/05/SciCHECKsquare_4-e1430162915812.png" alt="" width="243" height="219" srcset="https://cdn.factcheck.org/wp-content/uploads/2016/05/SciCHECKsquare_4-e1430162915812.png 243w, https://cdn.factcheck.org/wp-content/uploads/2016/05/SciCHECKsquare_4-e1430162915812-161x145.png 161w" sizes="(max-width: 243px) 100vw, 243px"/>The most recent analysis of what&#8217;s known about the effect of climate change on hurricane activity comes from the June 28 <a href="https://assets.documentcloud.org/documents/3920195/Final-Draft-of-the-Climate-Science-Special-Report.pdf">draft</a> of the U.S. Global Change Research Program&#8217;s Climate Science Special Report.</p><p>One of that report&#8217;s key findings said that human activities have &#8220;contributed to the observed increase in hurricane activity&#8221; in the North Atlantic Ocean since the 1970s. The <a href="https://www.cia.gov/library/publications/the-world-factbook/geos/print_zh.html">Gulf of Mexico</a>, where Harvey <a href="https://www.nytimes.com/2017/08/30/us/hurricane-center-timeline.html">formed</a>, is part of the North Atlantic Ocean.</p><p>The draft report echoes the findings of the U.N.’s Intergovernmental Panel on Climate Change’s <a href="http://www.climatechange2013.org/images/report/WG1AR5_Chapter02_FINAL.pdf">2013 assessment report</a>, which found that scientists are “virtually certain” (99 percent to 100 percent confident) that there has been an “increase in the frequency and intensity of the strongest tropical cyclones since the 1970s” in the North Atlantic Ocean.</p><p>Still, the U.S. Global Change research program&#8217;s report says there&#8217;s uncertainty in how much humans have contributed to hurricane activity relative to natural causes. The studies that have looked at this question have come up with a &#8220;fairly broad&#8221; range of contributions for humans, but &#8220;virtually all studies identify a measurable, and generally substantial, [human] influence,&#8221; it adds.</p><p>Another key finding of the report concluded that climate models generally show that a &#8220;warmer world&#8221; leads to an increase in the intensity of hurricanes, as well as an increase in the frequency of &#8220;very intense&#8221; hurricanes. The report also says the Atlantic Ocean specifically is projected to see increases in hurricane precipitation.</p><p>These projections also fit with scientists&#8217; theories about how a warmer world leads to greater moisture in the atmosphere, which leads to greater precipitation, which leads to more intense storms.</p><p>But there is some uncertainty: The projections don&#8217;t yet align with the observed data on hurricanes because the data are &#8220;not of a high enough quality&#8221; to detect human contribution to the trend, the report says.</p><p>What about Hurricane Harvey in particular?</p><p>As we&#8217;ve said, it&#8217;s inaccurate to say that climate change is the cause of Harvey, which dumped a record <a href="https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/08/29/harvey-marks-the-most-extreme-rain-event-in-u-s-history/?utm_term=.7120657edbf9">50 inches</a> of rain on southern Texas over four days.</p><p>But <a href="https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly">scientists</a> <a href="https://www.washingtonpost.com/news/energy-environment/wp/2017/08/25/what-you-can-and-cant-say-about-climate-change-and-hurricane-harvey/?utm_term=.d065ea0470cc">have</a> <a href="https://www.theatlantic.com/science/archive/2017/08/did-climate-change-intensify-hurricane-harvey/538158/">said</a> that Harvey was likely worsened by climate change for a few reasons.</p><p><a href="http://www.meteo.psu.edu/holocene/public_html/Mann/about/">Michael Mann</a>, a professor of atmospheric science at Penn State, pointed to at least three factors that likely affected Harvey &#8212; higher sea levels, warmer ocean waters and weak prevailing winds &#8212; in an <a href="https://www.theguardian.com/commentisfree/2017/aug/28/climate-change-hurricane-harvey-more-deadly">article</a> published in the <em>Guardian</em> on Aug. 28.</p><p>Sea level rise contributes to higher storm surges, explains Mann. Higher storm surges then lead to more coastal flooding, he says.</p><p>Warmer waters, on the other hand, lead to increased moisture in the atmosphere, which &#8220;creates the potential for much greater rainfalls and greater flooding,&#8221; Mann explains. &#8220;The combination of coastal flooding and heavy rainfall is responsible for the devastating flooding that Houston is experiencing.&#8221;</p><p>Though &#8220;more tenuous&#8221; than the other two factors, says Mann, Harvey also may have stalled near the coast because of weak prevailing winds that failed &#8220;to steer the storm off to sea.&#8221; This stalling then led to continued heavy rainfall on Texas that eventually topped 50 inches.</p><p>The weak prevailing winds are caused by a &#8220;greatly expanded subtropical high pressure system&#8221; currently over much of the U.S., which is &#8220;predicted in model simulations of human-caused climate change,&#8221; says Mann.</p><p>Scientists say other storms were likely made worse by climate change as well.</p><p>In a perspective <a href="http://www.nature.com/nclimate/journal/v5/n8/full/nclimate2657.html#affil-auth">paper</a> published in <em>Nature Climate Change</em> in 2015, <span class="fn"><a href="http://www.cgd.ucar.edu/staff/trenbert/">Kevin E. Trenberth</a>, a senior scientist at the National Center for Atmospheric Research in Colorado, and others discussed how climate change likely affected Hurricane Sandy,</span> which hit New York and New Jersey particularly hard in October 2012.</p><blockquote><p><strong>Trenberth et al., June 2015:</strong> Although perhaps only one-half to one-third of the [sea surface temperature] increase can be blamed on global warming from human activities, it is readily apparent that the storm surge and associated damage was considerably influenced by climate change. It is quite possible that the subways and tunnels [in and around New York City] might not have flooded without the warming-induced increases in sea level and in storm intensity and size, putting a potential price tag of human climate change on this storm in the tens of billions of dollars.</p></blockquote><p>So is climate change all to blame for Harvey? No. But it did play a role in making the storm worse, as it has with other storms, scientists say.</p><p><em>Editor’s Note: SciCheck is made possible by a grant from the Stanton Foundation. For more information about extreme weather and climate change, please see our item &#8220;<a href="https://www.factcheck.org/2017/03/precision-in-climate-science/">Precision in Climate Science</a>.&#8221;</em></p><div class="at-below-post addthis_tool" data-url="https://www.factcheck.org/2017/08/hurricane-harvey-climate-change/"></div> </div> <footer class="entry-footer"> <div class="term-listing-footer"><ul><li class="categories">Categories<ul> <li class="cat-item cat-item-2707"><a href="https://www.factcheck.org/scicheck/" >SciCheck</a></li> <li class="cat-item cat-item-4"><a href="https://www.factcheck.org/the-factcheck-wire/" >The Wire</a></li></ul></li><li class="location">Location<ul> <li class="cat-item cat-item-2465"><a href="https://www.factcheck.org/location/international/" >International</a></li> <li class="cat-item cat-item-2464"><a href="https://www.factcheck.org/location/national/" >National</a></li></ul></li><li class="issue">Issue<ul> <li class="cat-item cat-item-27"><a href="https://www.factcheck.org/issue/climate-change/" >climate change</a></li> <li class="cat-item cat-item-3011"><a href="https://www.factcheck.org/issue/extreme-weather-2/" >extreme weather</a></li> <li class="cat-item cat-item-445"><a href="https://www.factcheck.org/issue/global-warming/" >global warming</a></li> <li class="cat-item cat-item-4754"><a href="https://www.factcheck.org/issue/hurricane-harvey/" >hurricane harvey</a></li></ul></li></ul></div> </footer></article> <hr> <nav class="container navigation post-navigation"> <div class="row nav-links justify-content-between"> <a class="col-6 post-pagination-wrapper" href="https://www.factcheck.org/2017/08/trump-didnt-fire-14-muslim-judges/"><div class="post-pagination-block"><span class="post-pagination-header">Previous Story</span><span class="nav-previous">Trump Didn&#8217;t Fire 14 Muslim Judges</span></div></a><a class="col-6 post-pagination-wrapper" href="https://www.factcheck.org/2017/08/will-trumps-wall-stop-drug-smuggling/"><div class="post-pagination-block"><span class="post-pagination-header">Next Story</span><span class="nav-nextious">Will Trump&#8217;s Wall Stop Drug Smuggling?</span></div></a> </div> </nav> </main> <hr class="d-block d-sm-none"> </div>  <div class="col-md-4 widget-area" id="right-sidebar" role="complementary"> <aside id="factcheck_additional_resources_widget-2" class="widget widget_factcheck_additional_resources_widget"><aside id="factcheck_ask_widget-2" class="widget widget_factcheck_ask_widget"><div class="fc-ask-widget"><h5>Ask FactCheck</h5><div class="at-above-post addthis_tool" data-url="https://www.factcheck.org/2018/02/adam-schiff-george-soros-not-laws/"></div><p><strong><span style="color: #993300;"><span style="font-size: x-large; color: #800000;">Q:</span> </span>Is Rep. Adam Schiff&#8217;s sister married to the son of George Soros?</strong><strong><br/></strong></p><p><strong><span style="color: #993300;"><span style="font-size: x-large; color: #800000;">A:</span> </span>No. The congressman doesn&#8217;t even have a sister.</strong></p><div class="at-below-post addthis_tool" data-url="https://www.factcheck.org/2018/02/adam-schiff-george-soros-not-laws/"></div><div style="text-align:right"><a href="https://www.factcheck.org/2018/02/adam-schiff-george-soros-not-laws/">Read the full question and answer</a></div><div style="text-align:right"></div><div style="text-align:right"> <a href="https://www.factcheck.org/askfactcheck/">View the Ask FactCheck archives</a></div><div style="text-align:right">Have a question? <a href="https://www.factcheck.org/ask-factcheck/ask-us-a-question/">Ask us.</a></div> </div><aside id="factcheck_donate_widget-2" class="widget widget_factcheck_donate_widget"> <a href="https://giving.aws.cloud.upenn.edu/?fastStart=simpleForm&amp;program=ANS&amp;fund=602014" rel="noopener" title="Because facts matter." target="_blank" class="fc-donate-widget-wrapper"> <div class="fc-donate-widget"> <div class="fc-donate-widget-head">Donate Now</div> <div class="fc-donate-widget-subhead">Because facts matter.</div> </div> </a> <aside id="factcheck_widget_links-2" class="widget widget_factcheck_widget_links"> <div class="fc-links-widget"> <a href="https://www.factcheck.org/scicheck/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-scicheck.png" class="img-fluid" alt="SciCheck"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>SciCheck</h5> <h6 class="d-none d-sm-block">Fact-checking science-based claims.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/issue/health-watch/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-healthwatch.png" class="img-fluid" alt="Health Watch"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Health Watch</h5> <h6 class="d-none d-sm-block">Fact-checking the health care debate.</h6> </div> </div> </div> </a> <a href="http://transcripts.factcheck.org/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-trump.png" class="img-fluid" alt="Trump Transcripts"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Trump Transcripts</h5> <h6 class="d-none d-sm-block">Annotated transcripts of Trump’s remarks.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/fake-news/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-facebook.png" class="img-fluid" alt="Facebook Initiative"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Facebook Initiative</h5> <h6 class="d-none d-sm-block">Debunking false stories.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/state-of-the-union-with-jake-tapper/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-sotu.png" class="img-fluid" alt="State of the Union"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>State of the Union</h5> <h6 class="d-none d-sm-block">Our fact-checking video collaboration.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/subscribe"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-signup.png" class="img-fluid" alt="Sign Up"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Sign Up</h5> <h6 class="d-none d-sm-block">Get free email alerts.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/askscicheck/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-askscicheck.png" class="img-fluid" alt="Ask SciCheck"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Ask SciCheck</h5> <h6 class="d-none d-sm-block">Answers to your science questions.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/hot-topics/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-viralspiral.png" class="img-fluid" alt="Viral Spiral"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Viral Spiral</h5> <h6 class="d-none d-sm-block">Don’t get spun by internet rumors.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/survey-page/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-quiz.png" class="img-fluid" alt="The Quiz"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>The Quiz</h5> <h6 class="d-none d-sm-block">Test your political knowledge.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/on-the-air"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-ota.png" class="img-fluid" alt="On the Air"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>On the Air</h5> <h6 class="d-none d-sm-block">Our staff on TV and radio.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/party-lines/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-partylines.png" class="img-fluid" alt="Party Lines"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Party Lines</h5> <h6 class="d-none d-sm-block">Misleading political talking points.</h6> </div> </div> </div> </a> <a href="http://www.flackcheck.org/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-flackcheck.png" class="img-fluid" alt="FlackCheck.org"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>FlackCheck.org</h5> <h6 class="d-none d-sm-block">Our sister site for political literacy.</h6> </div> </div> </div> </a> <a href="https://www.factcheck.org/factcheck-mailbag/"> <div class="row fc-links-widget-row"> <div class="col-2 col-sm-4"> <img src="https://cdn.factcheck.org/UploadedFiles/fc-icon-mailbag.png" class="img-fluid" alt="Mailbag"> </div> <div class="col-10 col-sm-8"> <div class="fc-links-text"> <h5>Mailbag</h5> <h6 class="d-none d-sm-block">Letters from our readers.</h6> </div> </div> </div> </a> </div> </div> </div></div></div><div class="wrapper" id="wrapper-footer"> <div class="container"> <div class="row"> <div class="col-md-12"> <footer class="site-footer" id="colophon"> <div class="site-info"> <div class="menu-footer-menu-container"><ul id="menu-footer-menu" class="menu"><li id="menu-item-122847" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-122847"><a href="https://www.factcheck.org/archives/">Archives</a></li><li id="menu-item-46791" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-46791"><a href="https://www.factcheck.org/privacy/">Privacy</a></li><li id="menu-item-46792" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-46792"><a href="https://www.factcheck.org/about/copyright-policy/">Copyright Policy</a></li><li id="menu-item-122853" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-122853"><a href="https://www.factcheck.org/about/contact-us/">Contact Us</a></li></ul></div> </div> <span class="copyright-text">&copy; Copyright 2018 FactCheck.org <sup>&reg;</sup><br>A Project of The Annenberg Public Policy Center of the University of Pennsylvania</span> </footer> </div> </div> </div></div></div><script data-cfasync="false" type="text/javascript">if (window.addthis_product === undefined) { window.addthis_product = "wpp"; } if (window.wp_product_version === undefined) { window.wp_product_version = "wpp-6.1.2"; } if (window.wp_blog_version === undefined) { window.wp_blog_version = "4.9.4"; } if (window.addthis_share === undefined) { window.addthis_share = {}; } if (window.addthis_config === undefined) { window.addthis_config = {"data_track_clickback":true,"ui_atversion":"300"}; } if (window.addthis_plugin_info === undefined) { window.addthis_plugin_info = {"info_status":"enabled","cms_name":"WordPress","plugin_name":"Share Buttons by AddThis","plugin_version":"6.1.2","plugin_mode":"AddThis","anonymous_profile_id":"wp-66cc4a54b9c57556656a9985c0457bb7","page_info":{"template":"posts","post_type":""},"sharing_enabled_on_post_via_metabox":false}; } 
                    (function() {
                      var first_load_interval_id = setInterval(function () {
                        if (typeof window.addthis !== 'undefined') {
                          window.clearInterval(first_load_interval_id);
                          if (typeof window.addthis_layers !== 'undefined' && Object.getOwnPropertyNames(window.addthis_layers).length > 0) {
                            window.addthis.layers(window.addthis_layers);
                          }
                          if (Array.isArray(window.addthis_layers_tools)) {
                            for (i = 0; i < window.addthis_layers_tools.length; i++) {
                              window.addthis.layers(window.addthis_layers_tools[i]);
                            }
                          }
                        }
                     },1000)
                    }());
                </script><script type='text/javascript' src='https://s7.addthis.com/js/300/addthis_widget.js?ver=567df1931476fe3d8d7d3feecf09702d#pubid=ra-4e778f700afff993'></script><script type='text/javascript' src='https://code.jquery.com/jquery-latest.min.js?ver=567df1931476fe3d8d7d3feecf09702d'></script><script type='text/javascript' src='https://cdn.factcheck.org/wp-content/themes/factcheckstrap/js/child-theme.min.js?ver=567df1931476fe3d8d7d3feecf09702d'></script><script>(function(w, d){
	var b = d.getElementsByTagName("body")[0];
	var s = d.createElement("script"); s.async = true;
	var v = !("IntersectionObserver" in w) ? "8.5.2" : "10.3.5";
	s.src = "https://cdn.factcheck.org/wp-content/plugins/wp-rocket/inc/front/js/lazyload-" + v + ".min.js";
	w.lazyLoadOptions = {
		elements_selector: "img, iframe",
		data_src: "lazy-src",
		data_srcset: "lazy-srcset",
		skip_invisible: false,
		class_loading: "lazyloading",
		class_loaded: "lazyloaded",
		threshold: 300,
		callback_load: function(element) {
			if ( element.tagName === "IFRAME" && element.dataset.rocketLazyload == "fitvidscompatible" ) {
				if (element.classList.contains("lazyloaded") ) {
					if (typeof window.jQuery != "undefined") {
						if (jQuery.fn.fitVids) {
							jQuery(element).parent().fitVids();
						}
					}
				}
			}
		}
	}; // Your options here. See "recipes" for more information about async.
	b.appendChild(s);
}(window, document));

// Listen to the Initialized event
window.addEventListener('LazyLoad::Initialized', function (e) {
    // Get the instance and puts it in the lazyLoadInstance variable
	var lazyLoadInstance = e.detail.instance;

	var observer = new MutationObserver(function(mutations) {
		mutations.forEach(function(mutation) {
			lazyLoadInstance.update();
		} );
	} );
	
	var b      = document.getElementsByTagName("body")[0];
	var config = { childList: true, subtree: true };
	
	observer.observe(b, config);
}, false);
</script></body></html>
<!-- This website is like a Rocket, isn't it? Performance optimized by WP Rocket. Learn more: https://wp-rocket.me - Debug: cached@1518499822 -->