1 00:00:01,920 --> 00:00:06,360 Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey 2 00:00:06,440 --> 00:00:09,400 Speaker 1: brain Stuff, Lauren Vogel Bomb here with a classic episode 3 00:00:09,400 --> 00:00:13,399 Speaker 1: from the podcast archives. Some of the effects of human 4 00:00:13,480 --> 00:00:18,560 Speaker 1: induced climate change are pretty familiar and obvious, changing temperatures 5 00:00:18,560 --> 00:00:23,599 Speaker 1: and weather patterns, But of course those effects have other effects, 6 00:00:23,880 --> 00:00:27,400 Speaker 1: and this episode is about one of them. More storms 7 00:00:27,560 --> 00:00:31,960 Speaker 1: means more sand is getting pulled from some beaches. Here's 8 00:00:32,080 --> 00:00:34,360 Speaker 1: one of the things that researchers are trying to do 9 00:00:34,440 --> 00:00:39,720 Speaker 1: about it. Hey brain Stuff, Lauren Vogel bomb Here. In summer, 10 00:00:39,760 --> 00:00:42,000 Speaker 1: there's nothing like feeling the sun on your face and 11 00:00:42,040 --> 00:00:45,320 Speaker 1: the sand between your toes. But the rising sea levels 12 00:00:45,360 --> 00:00:48,960 Speaker 1: and stronger coastal storms associated with climate change pose a 13 00:00:49,040 --> 00:00:51,600 Speaker 1: threat to the sands that make up our beaches. A 14 00:00:51,600 --> 00:00:55,400 Speaker 1: common approach to combating erosion at US coastlines is beach nourishment, 15 00:00:55,640 --> 00:00:58,400 Speaker 1: which is literally taking sand from one place off and 16 00:00:58,440 --> 00:01:01,600 Speaker 1: off shore and pumping it on to a sand depleted beach. 17 00:01:02,480 --> 00:01:05,440 Speaker 1: The question is can beach nourishment keep up with the 18 00:01:05,520 --> 00:01:09,280 Speaker 1: ever increasing forces of climate change, or, like Sisyphus forever 19 00:01:09,360 --> 00:01:11,880 Speaker 1: pushing his boulder up the hill, is adding sand to 20 00:01:11,959 --> 00:01:16,480 Speaker 1: beaches an expensive temporary fix to a long term problem. 21 00:01:16,560 --> 00:01:19,240 Speaker 1: We spoke with Bonnie Lutka, a post doc at Script's 22 00:01:19,240 --> 00:01:22,920 Speaker 1: Institution of Oceanography at the University of California in San Diego. 23 00:01:23,520 --> 00:01:26,399 Speaker 1: She said, I think there's reason to be concerned, but 24 00:01:26,480 --> 00:01:28,560 Speaker 1: I also think there's still a lot we don't know 25 00:01:28,640 --> 00:01:31,720 Speaker 1: about how long the sand stays where it goes, and 26 00:01:31,760 --> 00:01:33,679 Speaker 1: how much sand you need to place on a beach 27 00:01:33,720 --> 00:01:37,559 Speaker 1: to be effective or learning as we go. A study 28 00:01:37,560 --> 00:01:40,679 Speaker 1: published by Luca in the June issue of the journal 29 00:01:40,720 --> 00:01:44,720 Speaker 1: Coastal Engineering examines exactly what happened to sand deposited on 30 00:01:44,800 --> 00:01:48,280 Speaker 1: four beaches in San Diego County in California. She and 31 00:01:48,320 --> 00:01:50,680 Speaker 1: her colleagues used jet skis, a t v S, and 32 00:01:50,760 --> 00:01:54,280 Speaker 1: other tools to continuously monitor sand levels and sand movement 33 00:01:54,320 --> 00:01:56,880 Speaker 1: at the beaches over a period of about ten years. 34 00:01:57,480 --> 00:01:59,800 Speaker 1: The research received funding from the U. S. Army Corps 35 00:01:59,760 --> 00:02:02,720 Speaker 1: of an Engineers, the California Department of Parks and Recreation, 36 00:02:03,000 --> 00:02:07,200 Speaker 1: the National Science Foundation, and the California Sea Grant. Among 37 00:02:07,240 --> 00:02:09,920 Speaker 1: their findings, the team learned that the entire amount of 38 00:02:09,919 --> 00:02:12,600 Speaker 1: sand added to San Diego's Tory Pines in two thousand 39 00:02:12,639 --> 00:02:16,640 Speaker 1: one was washed away during a single storm. At another beach, 40 00:02:16,680 --> 00:02:19,240 Speaker 1: the addition of a hundred and thirty eight Olympic swimming 41 00:02:19,280 --> 00:02:22,400 Speaker 1: pools worth of sand contributed to the clogging and eventual 42 00:02:22,440 --> 00:02:26,120 Speaker 1: closure of a nearby estuary. Among the team's more positive 43 00:02:26,120 --> 00:02:29,320 Speaker 1: findings was that larger grained sand appeared to have better 44 00:02:29,320 --> 00:02:32,880 Speaker 1: staying power than finer grained sand, and in some cases, 45 00:02:33,080 --> 00:02:35,520 Speaker 1: the amount of sand deposited to a beach by natural 46 00:02:35,560 --> 00:02:40,320 Speaker 1: forces was comparable to any mechanically added sand. Luca said, 47 00:02:40,680 --> 00:02:43,359 Speaker 1: there is quite a bit of natural variability, so it's 48 00:02:43,400 --> 00:02:46,280 Speaker 1: hard to pick out trends, but at our longest recorded site, 49 00:02:46,280 --> 00:02:50,400 Speaker 1: we did see an overall pattern of erosion. The pattern 50 00:02:50,440 --> 00:02:53,040 Speaker 1: of erosion that Luca's team observed at ground level is 51 00:02:53,080 --> 00:02:56,240 Speaker 1: what's alarming to researchers assessing the long term future of 52 00:02:56,360 --> 00:03:00,360 Speaker 1: US beaches. With climate change, sea level has risen about 53 00:03:00,440 --> 00:03:04,720 Speaker 1: eight inches that's twenty since nine, according to the Intergovernmental 54 00:03:04,720 --> 00:03:07,720 Speaker 1: Panel on Climate Change, and could rise three to five 55 00:03:07,720 --> 00:03:10,680 Speaker 1: feet higher that's point nine to one point five meters 56 00:03:10,720 --> 00:03:14,160 Speaker 1: by the end of this century. More frequent coastal storms, 57 00:03:14,200 --> 00:03:17,120 Speaker 1: also associated with climate change, take a further toll on 58 00:03:17,200 --> 00:03:20,240 Speaker 1: beaches by unleashing rough waves that eat away at the shore. 59 00:03:21,200 --> 00:03:23,920 Speaker 1: We also spoke with Michael or Back, Professor emeritus of 60 00:03:23,960 --> 00:03:27,800 Speaker 1: Marine Affairs and Policy at Duke University. He said, any 61 00:03:27,840 --> 00:03:31,239 Speaker 1: beach nourishment is forever. It's like painting a house. Once 62 00:03:31,280 --> 00:03:33,480 Speaker 1: you start it, you have to keep doing it forever 63 00:03:33,560 --> 00:03:36,800 Speaker 1: to maintain. The problem is, with climate change and rising 64 00:03:36,840 --> 00:03:39,640 Speaker 1: sea levels, there's going to be even more demand by 65 00:03:39,760 --> 00:03:42,680 Speaker 1: orders of magnitude because the beaches are going to erode 66 00:03:42,760 --> 00:03:47,080 Speaker 1: more and faster. Western Carolina University's Program for the Study 67 00:03:47,080 --> 00:03:50,400 Speaker 1: of Developed Shorelines hosts an interactive database of beach nourishment 68 00:03:50,440 --> 00:03:54,560 Speaker 1: projects across the US and their costs. As the data show, 69 00:03:54,760 --> 00:03:58,360 Speaker 1: beach nourishment today is not cheap. Or Bach estimates the 70 00:03:58,400 --> 00:04:01,440 Speaker 1: average cost of supplementing, saye that beaches comes out between 71 00:04:01,600 --> 00:04:05,400 Speaker 1: one and two million dollars per mile of sand. As 72 00:04:05,440 --> 00:04:08,400 Speaker 1: the demand for sand four beach nourishment increases, the cost 73 00:04:08,440 --> 00:04:12,000 Speaker 1: will rise even higher. Orbach predicts, he said, in the end, 74 00:04:12,120 --> 00:04:15,280 Speaker 1: there may not be enough sand that's economically recoverable to 75 00:04:15,320 --> 00:04:18,800 Speaker 1: nourish every beach that people want to nourish. There's also 76 00:04:18,880 --> 00:04:22,320 Speaker 1: an ecological cost. Studies have shown that dredging and depositing 77 00:04:22,360 --> 00:04:24,960 Speaker 1: sand is disruptive to creatures living in the sand and 78 00:04:25,120 --> 00:04:28,320 Speaker 1: the animals that eat them. While the research suggests those 79 00:04:28,360 --> 00:04:31,159 Speaker 1: animals tend to recover after eighteen months to two years, 80 00:04:31,480 --> 00:04:34,919 Speaker 1: beaches that undergo repeated nourishment to see significant declines in 81 00:04:34,960 --> 00:04:40,120 Speaker 1: animal life. Despite the economic and ecological costs of beach nourishment, 82 00:04:40,360 --> 00:04:43,120 Speaker 1: it may be among the few available options for preserving 83 00:04:43,160 --> 00:04:47,200 Speaker 1: beaches in the future. Sean Vita, sec, and engineer specializing 84 00:04:47,240 --> 00:04:50,120 Speaker 1: in ocean modeling at the University of Illinois and Chicago, 85 00:04:50,440 --> 00:04:53,640 Speaker 1: points out that natural sources of beach sand, including rivers 86 00:04:53,640 --> 00:04:56,680 Speaker 1: and eroding cliffs, have been suppressed by human built dams 87 00:04:56,680 --> 00:05:00,240 Speaker 1: and protective coverings. Vita Sex served as lead off of 88 00:05:00,279 --> 00:05:03,800 Speaker 1: a March seventeen modeling analysis from the U S Geological 89 00:05:03,839 --> 00:05:06,960 Speaker 1: Survey that concluded that if no measures are taken, up 90 00:05:06,960 --> 00:05:10,360 Speaker 1: to sixty seven percent of California's beaches could be completely 91 00:05:10,400 --> 00:05:13,520 Speaker 1: eroded back to sea cliffs or coastal infrastructure by the 92 00:05:13,560 --> 00:05:17,839 Speaker 1: year twenty one. The U S Geological Survey models showed 93 00:05:17,839 --> 00:05:20,440 Speaker 1: that beach nourishment could protect some larger beaches that have 94 00:05:20,520 --> 00:05:24,320 Speaker 1: undergone nourishment for decades, but that overall beach nourishment will 95 00:05:24,320 --> 00:05:26,440 Speaker 1: have to be stepped up to a much faster pace 96 00:05:26,520 --> 00:05:29,719 Speaker 1: to continue to be at all effective. Vita Sex said, 97 00:05:30,080 --> 00:05:32,159 Speaker 1: if you just dump sand on a beach, that sand 98 00:05:32,240 --> 00:05:35,040 Speaker 1: is not going to stay there forever. The current methodical 99 00:05:35,120 --> 00:05:38,279 Speaker 1: rate of beach nourishment is insufficient against the coming sea 100 00:05:38,360 --> 00:05:42,520 Speaker 1: level rise. Ludca said there is quite some debate about 101 00:05:42,560 --> 00:05:46,120 Speaker 1: how climate change will influence the frequency and intensity of storms, 102 00:05:46,360 --> 00:05:48,960 Speaker 1: and these storms will be more responsible for beach evolution 103 00:05:49,200 --> 00:05:52,320 Speaker 1: than sea level rise. In the next few decades. It 104 00:05:52,360 --> 00:05:55,360 Speaker 1: may become, she says, a matter of choosing between investing 105 00:05:55,400 --> 00:05:58,800 Speaker 1: in ever pricier efforts to preserve beaches or standing back 106 00:05:58,839 --> 00:06:01,720 Speaker 1: and allowing nature's forces to redraw the lines of where 107 00:06:01,720 --> 00:06:09,840 Speaker 1: the ocean meets the land. Today's episode is based on 108 00:06:09,880 --> 00:06:12,760 Speaker 1: the article can adding sand to beaches save them? On 109 00:06:12,800 --> 00:06:15,720 Speaker 1: how stuff Works dot com written by Amanda Onion. Bran 110 00:06:15,800 --> 00:06:18,040 Speaker 1: Stuff is production of iHeart Radio in partnership with how 111 00:06:18,040 --> 00:06:20,280 Speaker 1: stuff Works dot Com, and it is produced by Tyler Klang. 112 00:06:20,800 --> 00:06:23,279 Speaker 1: Four more podcasts from my heart Radio visit the iHeart 113 00:06:23,320 --> 00:06:25,920 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 114 00:06:25,920 --> 00:06:26,679 Speaker 1: favorite shows.