0:00:00.792,0:00:04.351 When you imagine the architectural[br]wonders of the world, 0:00:04.375,0:00:05.684 what do you see? 0:00:05.708,0:00:07.726 The greatness of the Pyramids of Giza 0:00:07.750,0:00:11.643 or maybe the amazing[br]aqueducts of Ancient Rome? 0:00:11.667,0:00:15.976 Both of these are amazing[br]feats of human innovation. 0:00:16.000,0:00:17.559 As an architect, 0:00:17.583,0:00:21.434 I've often wondered why do we[br]monumentalize the ancient wonders 0:00:21.458,0:00:25.601 of civilizations that collapsed[br]such a long time ago? 0:00:25.625,0:00:29.559 I've traveled the world[br]studying ancient innovation, 0:00:29.583,0:00:34.143 and what I've found are Indigenous[br]technologies from living cultures 0:00:34.167,0:00:36.143 that are still in use. 0:00:36.167,0:00:39.934 And some of these cultures[br]you may have never heard of. 0:00:39.958,0:00:43.059 They live in the most[br]remote places on earth, 0:00:43.083,0:00:48.351 facing environmental extremes[br]like desert drought and frequent flooding 0:00:48.375,0:00:50.518 for generations. 0:00:50.542,0:00:53.184 A couple of years ago,[br]I traveled to northern India 0:00:53.208,0:00:56.059 to a place overlooking[br]the plains of Bangladesh 0:00:56.083,0:00:58.226 where the Khasi people live 0:00:58.250,0:01:03.268 in a forest that receives more rainfall[br]than anywhere else on earth. 0:01:03.292,0:01:04.809 And during the monsoon season, 0:01:04.833,0:01:08.268 travel between villages[br]is cut off by these floods, 0:01:08.292,0:01:10.643 which transform this entire landscape 0:01:10.667,0:01:15.101 from a forested canopy[br]into isolated islands. 0:01:15.125,0:01:18.143 This hill tribe has evolved[br]living root bridges 0:01:18.167,0:01:20.809 that are created[br]by guiding and growing tree roots 0:01:20.833,0:01:24.268 that you can barely wrap your arms around 0:01:24.292,0:01:26.643 through a carefully woven scaffolding. 0:01:26.667,0:01:31.059 Multiple generations of the Khasi men[br]and the women and the children, 0:01:31.083,0:01:32.684 they'll take care of these roots 0:01:32.708,0:01:34.976 as they grow to the other[br]side of that bank, 0:01:35.000,0:01:37.309 where they're then planted[br]to make a structure 0:01:37.333,0:01:39.851 that will get stronger with age. 0:01:39.875,0:01:44.893 This 1,500-year-old tradition[br]of growing living root bridges 0:01:44.917,0:01:48.934 has produced 75[br]of these incredible structures. 0:01:48.958,0:01:52.226 And while they take 50 years to grow, 0:01:52.250,0:01:55.375 in this landscape[br]they actually last for centuries. 0:01:56.250,0:01:57.518 All across the globe, 0:01:57.542,0:02:02.559 I've seen cultures who have been[br]living with floods for thousands of years 0:02:02.583,0:02:07.434 by evolving these ancient technologies[br]that allow them to work with the water. 0:02:07.458,0:02:09.643 In the southern wetlands of Iraq, 0:02:09.667,0:02:14.101 which are formed by the confluence[br]of the Tigris and the Euphrates rivers, 0:02:14.125,0:02:17.559 a unique, water-based civilization lives. 0:02:17.583,0:02:20.976 For 6,000 years,[br]the Maʿdān have floated villages 0:02:21.000,0:02:26.018 on man-made islands that are constructed[br]from a single species of reed 0:02:26.042,0:02:27.643 that grows around them. 0:02:27.667,0:02:32.268 And the Qasab reed[br]is integral to every aspect of life. 0:02:32.292,0:02:35.018 It is food for water buffalo, 0:02:35.042,0:02:36.809 flour for humans 0:02:36.833,0:02:41.518 and building material[br]for these biodegradable, buoyant islands 0:02:41.542,0:02:43.476 and their cathedral-like houses 0:02:43.500,0:02:46.875 that they construct[br]in as little as three days. 0:02:47.917,0:02:49.518 And this dried Qasab reed, 0:02:49.542,0:02:51.643 it can be bundled into columns, 0:02:51.667,0:02:56.101 it can be woven into floors[br]or roofs or walls, 0:02:56.125,0:02:59.184 and it can also be twisted into a rope 0:02:59.208,0:03:03.976 that's used to bind these buildings[br]without the use of any nails. 0:03:04.000,0:03:07.601 The Maʿdān villages[br]are constructed in the marsh, 0:03:07.625,0:03:10.393 as they have been for generations, 0:03:10.417,0:03:16.351 on islands that stay afloat[br]for over 25 years. 0:03:16.375,0:03:20.309 Although global attention[br]is focused on the pandemic, 0:03:20.333,0:03:23.958 cities are still sinking[br]and sea levels are still rising. 0:03:24.875,0:03:26.184 And high-tech solutions 0:03:26.208,0:03:29.066 are definitely going to help us[br]solve some of these problems, 0:03:29.090,0:03:32.184 but in our rush towards the future, 0:03:32.208,0:03:34.434 we tend to forget about the past. 0:03:34.458,0:03:38.226 In other parts of the world,[br]where rivers are contaminated with sewage, 0:03:38.250,0:03:44.643 a city of 15 million people cleans[br]its waste water with its flood plains. 0:03:44.667,0:03:46.851 On the edges of Calcutta, 0:03:46.875,0:03:50.643 flanked by a smoking[br]escarpment of the city's trash 0:03:50.667,0:03:53.518 and ribboned by its highways, 0:03:53.542,0:03:57.018 an Indigenous technology of 300 fish ponds 0:03:57.042,0:04:00.726 cleans its water while producing its food. 0:04:00.750,0:04:04.643 And through a combination[br]of sunshine and sewage 0:04:04.667,0:04:08.518 and a symbiosis[br]between algae and bacteria, 0:04:08.542,0:04:10.893 the wastewater is broken down. 0:04:10.917,0:04:13.684 Fish ponds continue[br]this cleaning of the water 0:04:13.708,0:04:16.417 in a process that takes around 30 days. 0:04:17.375,0:04:18.643 And this innovation, 0:04:18.667,0:04:24.333 it's not just a model for chemical[br]and coal-power-free purification. 0:04:25.000,0:04:28.226 Since Calcutta's core[br]has no formal treatment, 0:04:28.250,0:04:31.434 it's the city's only way[br]of cleaning the water downstream 0:04:31.458,0:04:34.559 before it enters the Bay of Bengal. 0:04:34.583,0:04:38.768 What I find so unbelievable[br]about this infrastructure 0:04:38.792,0:04:42.934 is that as cities across the world[br]in Asia and in Europe 0:04:42.958,0:04:46.018 begin to replicate this exact system, 0:04:46.042,0:04:51.101 Calcutta is now struggling to save it[br]from being displaced by development. 0:04:51.125,0:04:54.726 And then to deal with flooding[br]in a completely other way, 0:04:54.750,0:04:58.833 the Tofinu tribe has developed[br]the largest lake city in Africa. 0:04:59.875,0:05:03.184 Ganvié, meaning "We survived," 0:05:03.208,0:05:06.893 is built of stilted houses that are[br]organized around a canal system 0:05:06.917,0:05:09.601 that you can navigate by dugout canoe. 0:05:09.625,0:05:14.268 And the royal square stands[br]amongst 3,000 stilted buildings 0:05:14.292,0:05:16.518 that include a post office, 0:05:16.542,0:05:18.559 a bank, a mosque 0:05:18.583,0:05:19.893 and even a couple of bars 0:05:19.917,0:05:24.893 that are all surrounded[br]by 12,000 individual fish paddocks, 0:05:24.917,0:05:27.018 or mangrove acadjas. 0:05:27.042,0:05:32.601 This chemical-free artificial reef[br]covers almost half of the lagoon 0:05:32.625,0:05:36.476 and feeds one million people[br]that are living around it. 0:05:36.500,0:05:37.851 What amazes me 0:05:37.875,0:05:42.934 is that while an individual acadja[br]is pretty insignificant, 0:05:42.958,0:05:45.976 when it's multiplied by 12,000, 0:05:46.000,0:05:51.101 it creates an Indigenous technology[br]the scale of industrial aquaculture, 0:05:51.125,0:05:55.309 which is the greatest threat[br]to our mangrove ecosystems ... 0:05:55.333,0:05:56.809 but this technology -- 0:05:56.833,0:06:00.059 it builds more biodiversity than before. 0:06:00.083,0:06:02.893 Just earlier this year,[br]when I was back home in Australia, 0:06:02.917,0:06:05.184 the craziest thing happened. 0:06:05.208,0:06:09.518 The burned ash from the bushfires[br]surrounding Sydney rained down on us 0:06:09.542,0:06:10.934 on Bondi Beach. 0:06:10.958,0:06:12.934 And worried about carbon emissions -- 0:06:12.958,0:06:14.393 not viral transmissions -- 0:06:14.417,0:06:17.393 we were already wearing masks. 0:06:17.417,0:06:19.893 The air was so choked by a plume of smoke 0:06:19.917,0:06:24.476 that was so big that it reached[br]as far away as New Zealand. 0:06:24.500,0:06:26.684 Then in the midst of these wildfires, 0:06:26.708,0:06:30.143 which were the worst[br]we'd ever seen on record, 0:06:30.167,0:06:32.018 something unexpected happened, 0:06:32.042,0:06:34.268 but incredibly amazing. 0:06:34.292,0:06:35.976 The ancestral lands in Australia, 0:06:36.000,0:06:38.726 where Indigenous fire-stick[br]farming was practiced, 0:06:38.750,0:06:42.059 were saved as these fires[br]raged around them. 0:06:42.083,0:06:43.434 And these ancient forests -- 0:06:43.458,0:06:47.059 they survived because of seasonal,[br]generational burning, 0:06:47.083,0:06:52.726 which is an Aboriginal practice[br]of lighting small, slow and cool fires. 0:06:52.750,0:06:56.143 So though wildfires[br]are a natural disaster, 0:06:56.167,0:06:58.601 as a consequence of climate change, 0:06:58.625,0:07:00.851 they're also man-made. 0:07:00.875,0:07:05.143 And what's so amazing about this[br]is we have the ancient technology 0:07:05.167,0:07:07.018 that we know can help prevent them, 0:07:07.042,0:07:10.268 and we've used it for thousands of years. 0:07:10.292,0:07:13.976 And what I find so fascinating[br]about these technologies 0:07:14.000,0:07:15.726 is how complex they are 0:07:15.750,0:07:17.643 and how attuned they are to nature. 0:07:17.667,0:07:20.643 And then, how resilient[br]we could all become 0:07:20.667,0:07:22.226 by learning from them. 0:07:22.250,0:07:27.684 Too often when we are faced with a crisis,[br]we build walls in defense. 0:07:27.708,0:07:29.018 I'm an architect, 0:07:29.042,0:07:32.434 and I've been trained[br]to seek solutions in permanence -- 0:07:32.458,0:07:35.351 concrete, steel, glass -- 0:07:35.375,0:07:39.351 these are all used to build[br]a fortress against nature. 0:07:39.375,0:07:43.184 But my search for ancient systems[br]and Indigenous technologies 0:07:43.208,0:07:44.601 has been different. 0:07:44.625,0:07:50.601 It's been inspired by an idea[br]that we can seed creativity in crisis. 0:07:50.625,0:07:54.101 We have thousands of years[br]of ancient knowledge 0:07:54.125,0:07:56.184 that we just need to listen to 0:07:56.208,0:08:01.393 and allow it to expand our thinking[br]about designing symbiotically with nature. 0:08:01.417,0:08:03.018 And by listening, 0:08:03.042,0:08:04.934 we'll only become wiser 0:08:04.958,0:08:08.184 and ready for those[br]21st-century challenges 0:08:08.208,0:08:13.018 that we know will endanger[br]our people and our planet. 0:08:13.042,0:08:14.601 And I've seen it. 0:08:14.625,0:08:15.958 I know that it's possible.