WEBVTT - BrainStuff Classics: Can Beaches Be Saved by Adding Sand? 0:00:01.920 --> 0:00:06.360 Welcome to brain Stuff production of I Heart Radio. Hey 0:00:06.440 --> 0:00:09.400 brain Stuff, Lauren Vogel Bomb here with a classic episode 0:00:09.400 --> 0:00:13.399 from the podcast archives. Some of the effects of human 0:00:13.480 --> 0:00:18.560 induced climate change are pretty familiar and obvious, changing temperatures 0:00:18.560 --> 0:00:23.599 and weather patterns, But of course those effects have other effects, 0:00:23.880 --> 0:00:27.400 and this episode is about one of them. More storms 0:00:27.560 --> 0:00:31.960 means more sand is getting pulled from some beaches. Here's 0:00:32.080 --> 0:00:34.360 one of the things that researchers are trying to do 0:00:34.440 --> 0:00:39.720 about it. Hey brain Stuff, Lauren Vogel bomb Here. In summer, 0:00:39.760 --> 0:00:42.000 there's nothing like feeling the sun on your face and 0:00:42.040 --> 0:00:45.320 the sand between your toes. But the rising sea levels 0:00:45.360 --> 0:00:48.960 and stronger coastal storms associated with climate change pose a 0:00:49.040 --> 0:00:51.600 threat to the sands that make up our beaches. A 0:00:51.600 --> 0:00:55.400 common approach to combating erosion at US coastlines is beach nourishment, 0:00:55.640 --> 0:00:58.400 which is literally taking sand from one place off and 0:00:58.440 --> 0:01:01.600 off shore and pumping it on to a sand depleted beach. 0:01:02.480 --> 0:01:05.440 The question is can beach nourishment keep up with the 0:01:05.520 --> 0:01:09.280 ever increasing forces of climate change, or, like Sisyphus forever 0:01:09.360 --> 0:01:11.880 pushing his boulder up the hill, is adding sand to 0:01:11.959 --> 0:01:16.480 beaches an expensive temporary fix to a long term problem. 0:01:16.560 --> 0:01:19.240 We spoke with Bonnie Lutka, a post doc at Script's 0:01:19.240 --> 0:01:22.920 Institution of Oceanography at the University of California in San Diego. 0:01:23.520 --> 0:01:26.399 She said, I think there's reason to be concerned, but 0:01:26.480 --> 0:01:28.560 I also think there's still a lot we don't know 0:01:28.640 --> 0:01:31.720 about how long the sand stays where it goes, and 0:01:31.760 --> 0:01:33.679 how much sand you need to place on a beach 0:01:33.720 --> 0:01:37.559 to be effective or learning as we go. A study 0:01:37.560 --> 0:01:40.679 published by Luca in the June issue of the journal 0:01:40.720 --> 0:01:44.720 Coastal Engineering examines exactly what happened to sand deposited on 0:01:44.800 --> 0:01:48.280 four beaches in San Diego County in California. She and 0:01:48.320 --> 0:01:50.680 her colleagues used jet skis, a t v S, and 0:01:50.760 --> 0:01:54.280 other tools to continuously monitor sand levels and sand movement 0:01:54.320 --> 0:01:56.880 at the beaches over a period of about ten years. 0:01:57.480 --> 0:01:59.800 The research received funding from the U. S. Army Corps 0:01:59.760 --> 0:02:02.720 of an Engineers, the California Department of Parks and Recreation, 0:02:03.000 --> 0:02:07.200 the National Science Foundation, and the California Sea Grant. Among 0:02:07.240 --> 0:02:09.920 their findings, the team learned that the entire amount of 0:02:09.919 --> 0:02:12.600 sand added to San Diego's Tory Pines in two thousand 0:02:12.639 --> 0:02:16.640 one was washed away during a single storm. At another beach, 0:02:16.680 --> 0:02:19.240 the addition of a hundred and thirty eight Olympic swimming 0:02:19.280 --> 0:02:22.400 pools worth of sand contributed to the clogging and eventual 0:02:22.440 --> 0:02:26.120 closure of a nearby estuary. Among the team's more positive 0:02:26.120 --> 0:02:29.320 findings was that larger grained sand appeared to have better 0:02:29.320 --> 0:02:32.880 staying power than finer grained sand, and in some cases, 0:02:33.080 --> 0:02:35.520 the amount of sand deposited to a beach by natural 0:02:35.560 --> 0:02:40.320 forces was comparable to any mechanically added sand. Luca said, 0:02:40.680 --> 0:02:43.359 there is quite a bit of natural variability, so it's 0:02:43.400 --> 0:02:46.280 hard to pick out trends, but at our longest recorded site, 0:02:46.280 --> 0:02:50.400 we did see an overall pattern of erosion. The pattern 0:02:50.440 --> 0:02:53.040 of erosion that Luca's team observed at ground level is 0:02:53.080 --> 0:02:56.240 what's alarming to researchers assessing the long term future of 0:02:56.360 --> 0:03:00.360 US beaches. With climate change, sea level has risen about 0:03:00.440 --> 0:03:04.720 eight inches that's twenty since nine, according to the Intergovernmental 0:03:04.720 --> 0:03:07.720 Panel on Climate Change, and could rise three to five 0:03:07.720 --> 0:03:10.680 feet higher that's point nine to one point five meters 0:03:10.720 --> 0:03:14.160 by the end of this century. More frequent coastal storms, 0:03:14.200 --> 0:03:17.120 also associated with climate change, take a further toll on 0:03:17.200 --> 0:03:20.240 beaches by unleashing rough waves that eat away at the shore. 0:03:21.200 --> 0:03:23.920 We also spoke with Michael or Back, Professor emeritus of 0:03:23.960 --> 0:03:27.800 Marine Affairs and Policy at Duke University. He said, any 0:03:27.840 --> 0:03:31.239 beach nourishment is forever. It's like painting a house. Once 0:03:31.280 --> 0:03:33.480 you start it, you have to keep doing it forever 0:03:33.560 --> 0:03:36.800 to maintain. The problem is, with climate change and rising 0:03:36.840 --> 0:03:39.640 sea levels, there's going to be even more demand by 0:03:39.760 --> 0:03:42.680 orders of magnitude because the beaches are going to erode 0:03:42.760 --> 0:03:47.080 more and faster. Western Carolina University's Program for the Study 0:03:47.080 --> 0:03:50.400 of Developed Shorelines hosts an interactive database of beach nourishment 0:03:50.440 --> 0:03:54.560 projects across the US and their costs. As the data show, 0:03:54.760 --> 0:03:58.360 beach nourishment today is not cheap. Or Bach estimates the 0:03:58.400 --> 0:04:01.440 average cost of supplementing, saye that beaches comes out between 0:04:01.600 --> 0:04:05.400 one and two million dollars per mile of sand. As 0:04:05.440 --> 0:04:08.400 the demand for sand four beach nourishment increases, the cost 0:04:08.440 --> 0:04:12.000 will rise even higher. Orbach predicts, he said, in the end, 0:04:12.120 --> 0:04:15.280 there may not be enough sand that's economically recoverable to 0:04:15.320 --> 0:04:18.800 nourish every beach that people want to nourish. There's also 0:04:18.880 --> 0:04:22.320 an ecological cost. Studies have shown that dredging and depositing 0:04:22.360 --> 0:04:24.960 sand is disruptive to creatures living in the sand and 0:04:25.120 --> 0:04:28.320 the animals that eat them. While the research suggests those 0:04:28.360 --> 0:04:31.159 animals tend to recover after eighteen months to two years, 0:04:31.480 --> 0:04:34.919 beaches that undergo repeated nourishment to see significant declines in 0:04:34.960 --> 0:04:40.120 animal life. Despite the economic and ecological costs of beach nourishment, 0:04:40.360 --> 0:04:43.120 it may be among the few available options for preserving 0:04:43.160 --> 0:04:47.200 beaches in the future. Sean Vita, sec, and engineer specializing 0:04:47.240 --> 0:04:50.120 in ocean modeling at the University of Illinois and Chicago, 0:04:50.440 --> 0:04:53.640 points out that natural sources of beach sand, including rivers 0:04:53.640 --> 0:04:56.680 and eroding cliffs, have been suppressed by human built dams 0:04:56.680 --> 0:05:00.240 and protective coverings. Vita Sex served as lead off of 0:05:00.279 --> 0:05:03.800 a March seventeen modeling analysis from the U S Geological 0:05:03.839 --> 0:05:06.960 Survey that concluded that if no measures are taken, up 0:05:06.960 --> 0:05:10.360 to sixty seven percent of California's beaches could be completely 0:05:10.400 --> 0:05:13.520 eroded back to sea cliffs or coastal infrastructure by the 0:05:13.560 --> 0:05:17.839 year twenty one. The U S Geological Survey models showed 0:05:17.839 --> 0:05:20.440 that beach nourishment could protect some larger beaches that have 0:05:20.520 --> 0:05:24.320 undergone nourishment for decades, but that overall beach nourishment will 0:05:24.320 --> 0:05:26.440 have to be stepped up to a much faster pace 0:05:26.520 --> 0:05:29.719 to continue to be at all effective. Vita Sex said, 0:05:30.080 --> 0:05:32.159 if you just dump sand on a beach, that sand 0:05:32.240 --> 0:05:35.040 is not going to stay there forever. The current methodical 0:05:35.120 --> 0:05:38.279 rate of beach nourishment is insufficient against the coming sea 0:05:38.360 --> 0:05:42.520 level rise. Ludca said there is quite some debate about 0:05:42.560 --> 0:05:46.120 how climate change will influence the frequency and intensity of storms, 0:05:46.360 --> 0:05:48.960 and these storms will be more responsible for beach evolution 0:05:49.200 --> 0:05:52.320 than sea level rise. In the next few decades. It 0:05:52.360 --> 0:05:55.360 may become, she says, a matter of choosing between investing 0:05:55.400 --> 0:05:58.800 in ever pricier efforts to preserve beaches or standing back 0:05:58.839 --> 0:06:01.720 and allowing nature's forces to redraw the lines of where 0:06:01.720 --> 0:06:09.840 the ocean meets the land. Today's episode is based on 0:06:09.880 --> 0:06:12.760 the article can adding sand to beaches save them? On 0:06:12.800 --> 0:06:15.720 how stuff Works dot com written by Amanda Onion. Bran 0:06:15.800 --> 0:06:18.040 Stuff is production of iHeart Radio in partnership with how 0:06:18.040 --> 0:06:20.280 stuff Works dot Com, and it is produced by Tyler Klang. 0:06:20.800 --> 0:06:23.279 Four more podcasts from my heart Radio visit the iHeart 0:06:23.320 --> 0:06:25.920 Radio app, Apple Podcasts, or wherever you listen to your 0:06:25.920 --> 0:06:26.679 favorite shows.