Coast Guard searching for missing cruise ship passenger near Key Largo

<p>Coastal areas in the U.S. have a problem: They&#39;re right next to the ocean.</p><p>Those oceans have been&nbsp;<a href="http://climate.nasa.gov/vital-signs/sea-level/" target="_blank">rising</a>&nbsp;since we started keeping track. Thanks to the changing climate, they&#39;re&nbsp;<a href="http://cpo.noaa.gov/AboutCPO/AllNews/TabId/315/ArtMID/668/ArticleID/80/Global-Sea-Level-Rise-Scenarios-for-the-United-States-National-Climate-Assessment.aspx" target="_blank">expected to keep rising</a>, anywhere from 8 inches to more than 6 feet in the next century. Now oceanfront communities have to figure out how to keep the waters at bay.</p><p><b>SEE MORE: <a href="http://www.newsy.com/videos/heavy-floods-from-hurricanes-could-become-more-common/">Climate Change Could Put New York City Underwater More Often</a></b></p><p>It can be as easy as rebuilding beaches.&nbsp;<a href="http://www.nj.com/news/index.ssf/2015/10/jersey_shore_beach_replenishment_cost_pegged_at_1b_over_past_30_years.html" target="_blank">New Jersey</a>&nbsp;and&nbsp;<a href="http://www.dep.state.fl.us/BEACHES/programs/becp/index.htm" target="_blank">Florida</a>&nbsp;have refilled sand on their coastlines for decades. New sand every few years can keep erosion in check and protect seaside structures.</p><p>Other projects are more permanent and more expensive. It cost&nbsp;<a href="http://www.nbcnews.com/storyline/hurricane-katrina-anniversary/new-orleans-14-5-billion-walls-n415816" target="_blank">$14.5 billion</a>&nbsp;to rebuild New Orleans&#39; levees after Katrina. New York City is&nbsp;<a href="http://www.nytimes.com/2016/01/19/nyregion/new-york-city-to-get-176-million-from-us-for-storm-protections.html" target="_blank">spending big</a>&nbsp;on a planned 10-foot barrier that will wrap around most of Lower Manhattan.</p><p>And in some cases, federal and state governments step in and buy a buffer against storm surges. After Hurricane Sandy,&nbsp;<a href="http://www.npr.org/2014/09/19/349559031/some-on-staten-island-opt-for-buyout-of-houses-that-dont-belong" target="_blank">New York</a>&nbsp;and&nbsp;<a href="http://www.nj.gov/dep/greenacres/pdf/faqs-blueacres.pdf" target="_blank">New Jersey</a>&nbsp;bought out damaged homes along the coast and turned them into open space.</p><p><a href="https://www.americanprogress.org/issues/green/reports/2013/12/12/81046/moving-out-of-harms-way/?elqIsAgent=True" target="_blank">Some experts think</a>&nbsp;the U.S. might need to do&nbsp;<a href="https://newrepublic.com/article/123182/managing-retreat-along-new-york-citys-coasts" target="_blank">even more drastic things</a>&nbsp;in the future, like moving further inland, away from swamped coasts. But it won&#39;t happen soon.&nbsp;<a href="http://oceanservice.noaa.gov/facts/population.html" target="_blank">Nearly 40 percent</a>&nbsp;of the U.S. lives in coastal counties, and the share is climbing right along with the sea level.</p><hr><b>Trending stories at <a href="http://www.newsy.com">Newsy.com</a></b><ul class="inline-related-links"><li><a href="http://www.newsy.com/videos/cases-of-potentially-deadly-fungal-infection-found-in-us/">Cases Of An Often Drug-Resistant Fungal Infection Were Found In The US</a></li><li><a href="http://www.newsy.com/videos/westerners-shoulder-blame-for-melting-artic-sea-ice/">Arctic Sea Ice Is Melting, And It&#039;s Partly Your Fault</a></li><li><a href="http://www.newsy.com/videos/daylight-saving-time-shown-to-cause-increase-in-depression/">Daylight Saving Time Is Good For Sleep But May Be Bad For Your Brain</a></li></ul>