voice-over: this is bbc news. we'll have the headlines and all the main news stories for you at the top of the hour, straight after this programme. in tecthlore, we go in search of some of the most exciting innovations in tech the world has to offer, and i can combine my two passions, tech and travel. this time, i'm injapan, a country facing big challenges from climate change.

you can turn these into batteries?— but i am here to see how its tech innovators are trying to help. is that lunch? very tasty. i will be seeing earth friendly energy project on land and at sea. the noise is really something else! putting the future fuels like hydrogen to the test... and understanding how nature can inspire totally new materials. absolutely massive! this is terrifying! thank you. welcome to japan! everything you could want, all in one place! japan is a place i know well, but as my green tech journey begins, i can already tell i going to see a different side to this great country.

i'm starting two hours east of tokyo in this sleepy port city which stares out at the mighty pacific ocean, whose weather often crashes into japan's shores. it is at sites like this you really get a sense of japan as an island nation, one that's very conscious of the threat posed by climate change. the typhoons and storms coming from out there are growing ever more powerful and the heatwaves and wildfires are becoming more common. going green is the only option. i'm here to meet somebody who advises on big renewable projects. i'm paul, lovely to meet you. hi paul! so good to meet you! this is beautiful. welcome to japan. it is very windy.

it's perfect for the wind turbine. it has historically relied heavily on imported fossil fuels but now aims to be carbon neutral by 2050. one answer lies at sea. wow. oh, god. wow indeed. three kilometres from land, this is japan's third spot on fixed onshore wind turbine, many others have popped up across the country recently. ash first item fixed offshore wind turbine. worldwide, wind is one of the fastest—growing green energies. japan is very energy poor. for energy security issues and full sustainability we need to do something. what are the challenges of installing and maintaining things like this in these kinds of conditions? any weather problems you can imagine, we have them. we have earthquakes,

we have tsunamis. lets hope none of them today. more than a fifth of japan's energy comes from green sources like solar and hydro power already, but with limited land to play with and one of the longest coastlines in the world it makes sense to put these out here. the noise is really something else. we are very close. it is quite intimidating being this close. the turbine you can see above the water is only half the story. deep under these weights these enormous structures had to be maintained, even in conditions like this —— deep under the waves. but this is not a job for the faint—hearted. having experienced the conditions myself, i can see why there might be a lack of divers wanting to do this work.

but while it is a challenge for humans, for robots it is less of a problem. i'm in tokyo to meet a team developing a drone to help with wind farm maintenance. welcome, welcome. this is your drone? what are the uses and applications? mainly to inspect and maintain the infrastructure underwater. things like wind turbines and dams? because they are hard for human divers to maintain? to support the divers or to replace theirjob, this has been developed. unlike a human this does not

get tired, i suppose. what is some of this equipment? it very complicated. it has led lights. very bright. wow! they are bri . ht. designed for inspections at 300 metres deep, navigation tools are vital. he explains that it has its own to avoid objects where visibility is not so good. the thrusters and sensors help the device withstand the waves, and of course a camera to record its findings. this is the camera, and it moves? oh, that's me! it is usually controlled from a boat but today it is time to take it for a test dive in a pool. shall we get it into the water and see it in action? there it goes.

the field specialist is ready to show me the moves, using a game controller for steering and manoeuvres. it is faster than i thought it would be. really responsive. i see we've got some things in the water too, a shrimp and lobster. is that our lunch? very tasty. this could go beyond basic reconnaissance. in the future we could grab or manipulate. it will be able to make repairs and do things as it goes? with its little lead, i saw this as an amiable pet. and of course i wanted to take it for a walk myself — well, a swim.

0h, wrong way! it is quite intuitive. like a video game. exactly. anyone i meet on the sea floor is on dangerous ground. 0h, oh, i 0h, ithink oh, i think i hit it stop sorry, mr lobster. this is undeniably fun, is the hot take from the tank! these drones may breathe new life to japan's historic maritime communities. we have brought it to many fisheries aboutjapan and had the local fishermen operate then, this fascinated them. it's kind of works as an additional revenue stream. if these fishermen could do lots of surveys and checking of the equipment it is a win—win for both us and the local community. but japan's push for green energy goes way beyond wind.

japan was one of the first to bet big on hydrogen, setting its sights several decades ago. now hydrogen is seen as a fuel to help meet climate change goals, the world is playing catch up and looking to japan. japanese car—makers toyota and honda were among the first to launch hydrogen cars. this is a toyota which takes just minutes to fill up at the hydrogen pump like this in tokyo. on a full charge it can travel about 550 kilometres, enough to get you about halfway across japan's main island. there are more than 100 filling stations injapan, more than anywhere

else in the world. apart from a few clues on the dashboard you would not know this is a hydrogen car, and in terms of ride quality it feels like any other ev. hydrogen is about much more than personal vehicles for japan. it wants to change its biggest polluters, something to think about as we whisk west on the famous bullet train to the hydrogen capital ofjapan, kobe. this is kobe. yeah! beautiful, isn't it? i often come here for leisure but it is also a place to see the technology of hydrogen. on port island, homes, hospitals and universities all receive heating

and electricity from hydrogen. kobe's docks are totally switching over to this fuel and the potential for this to transform the country, city and world at large which is huge. that energy comes from australia? that's right. yes, this pioneering project requires hydrogen to be shipped across the world so there are carbon emissions to be considered and hydrogen needs to be stored safely at a very low temperature. we had to think about social acceptance, there is the image that hydrogen is a bit dangerous, even though kerosene or other fuel is dangerous, we have not accumulated enough experience yet to be sure that using hydrogen is safe. from the technology side to the social aspect we have many things to overcome.

with the development of hydrogen fuel to planes, trains and automobiles, some applications face more trials than others. hydrogen produces only water, that is cool, but if we think about aviation, but it's not always cool when the water makes clouds, that is another climate change sources. it is almost solving one issue but creating a different one? yeah, the world is not easy to solve. it is hard not to be taken with japan's single—minded commitment to hydrogen over the years. seeking energy from the elements and pushing new sustainable fuels to the fore. and as kobe embarks on huge scaled—up hydrogen experiments

which will be watched by the rest of the world, i'm very excited to return to see what happens. despite being a global centre for energy, much land remains forested. a mindset of using natural resources wisely is widespread. this watering hole, for instance, turn seafood waste into decorations and light fittings. but i am here to try its speciality, something called a sea pineapple, a strange looking sea creature, a filter feeder with a squidgy shell. better give it a go. it actually tastes like the sea. i think that is what you would

call an acquired taste. i am not sure i would want to eat a whole one. to me, it tasted like burnt rubber, but whatever i think of it, thousands of tonnes of sea pineapples are harvested each year to eat, with thousands of tonnes of the squidgy shells thrown away. until now, because i've been told about a group of scientists doing something remarkable with all this waste. i am here to meet a university professor and his team. these are sea pineapples and this is what they look like fresh. that's right. they look very, very different in this kind of state. they are very strange. they are quite squidgy but leathery at the same time. this sea creature's shell is surprisingly rich in cellulose, an ingredient that can support electrical conduction.

why are they here in your lab, what are you doing with them? you can turn these into batteries? that is incredible. tiny cellulose fibres are extracted and mixed with another waste product from livestock, blood. all that is combined and popped into a vacuum. at 900 degrees celsius. how long will it take to become carbon? two or three hours. about the time it takes to make a roast dinner. but this is rather special, it is particularly strong and stable so battery cells like these can safely receive three times more power than traditional lithium—ion ones. can we see them in action? yeah, so, when we put the air inside here... oh, wow! i notice you have a phone plugged in here as well,

so you can charge the phone too? yeah. there we go, phenomenal. what incredible work. tabletop gizmos aside, sea pineapple waste could even power drones injust a few years and beyond that, electric vehicles. i feel like i should appreciate these things are little more. these could be the future. yeah. i still don't like touching them, though. almost every industry has an environmental impact but fashion is famously one of the world's biggest polluters. hey! hello. hello! nice to meet you! this is manon. a generation z pop icon and fashion influencer. she is giving me a tour of tokyo's street fashion. cheers! you don't need

the filter, i do! lots of pink around and bright colours. and cute ears. manon, like many young people here, deeply cares about her clothes' environmental footprint. do you think that particularly forjapanese younger people, for japanese younger people, that forjapanese younger people, that they are becoming more aware of sustainability and where their clothes might come from. i think so. vintage shops are getting more popular injapan because they are so cool. and also, i wear the vintage denim that my friends re—make. amazing. yes! this is the only one for me, i feel so special when i wear vintage clothes.

reusing and upcycling clothes is important for reducing waste, but really it is a drop in the ocean. if the fashion industry is going to become carbon neutral, it has to go a lot further and reinvent how it makes its clothes. so, i'm back on the road — this time to a rural yamagata, area 250 miles north of the capital where it started its weaving inspiration from nature, particularly spiders. scientists at this company have created a way to make a special protein polymer. so, here are the fermentation tanks. the microbes are in there. their oxygen and nutrient levels are closely monitored. and they are making the protein for us right now,

they are working very hard in there. ~ ., ~' , they are working very hard in there. ~ ., ~ , ., ., ~ there. working very hard. thank ou. it looks a little bit like beer but i imagine you probably do not want to drink it. these can be transformed into fibres and used to spin yarns, resulting in different materials. they felt similar to cotton or polyester. that is nice. this is still a relatively new tech so it will take a while until these garments can be made with brewed polymer only. the fashion industry uses around 27 million tonnes of cotton a year, so this is huge undertaking.

just before i go, there is a reason why this company is called spiber. i have to meet the creature that inspired all of this. i can't believe i'm about to do this, to be honest. even if it means facing one of my biggest fears. oh, my god! this is terrifying. uh, no! japan's golden orb weaver spider. absolutely massive! i swear, but one is looking at me. you'rejust going to put your hands right in there, yeah? 0h oh my goodness me. don't come too... oh, my god! now, i may not be their biggest fan but even i have to admit, they are rather remarkable. i'ill have nightmares tonight. but what will also stick with me is what spiber has done here in replicating

the spinning skills of these creatures in their labs. we have so much to learn from the natural world. looking out at this rugged, beautiful landscape, it's easy to see how innovators across japan are turning to nature for their inspiration. and maybe the answers to saving our cities, coasts and countryside — and ourfuture — could be out here. that's it for this tecthlore japan — a country that's leading the world in sustainable innovation, creating inspired, surprising and impactful technology. i will forever be amazed by the passion of its pioneers, those who are saving waste, forging future fashion and helping us go green on land and at sea.

hello there. it's been a pretty good week to have been on holiday in the uk and now, we've got the bank holiday weekend and prospects are looking good again — not too many changes, a lot of dry weather, sunshine. it may turn a bit cooler as the weekend goes on. essentially, high pressure is still in charge, keeping it dry for the most part. the only fly in the ointment — and it's a small fly — is that weak weather

front that's coming down from the north—west, and some stronger winds will bring more cloud down into scotland and northern ireland, but not much rain, as you can see. some sunshine in the north—west later on. south east scotland — dry, bright and quite warm. some patchy cloud for northern england. sunnier skies further south for england and wales and not as windy in the south on saturday. it's going to be a warmer day for england and wales — temperatures widely reaching 22, 23 degrees. cooler weather, though, arrives in the north—west of scotland, and that cooler air follows that weak weather front that's heading out into the north sea. high pressure then builds in behind that and that cooler air topples down from the north. so, as we head into sunday, maybe some changes to come. starting off quite sunny in most places but increasing amounts of cloud with the best of the sunshine hanging on across the western side of the uk. and the highest temperatures are getting squeezed down towards the south—west. it's cooler in northern and eastern areas. a significant drop in temperature, i think, for the north—east of england on sunday. but we've still got the high

pressure around, so it's keeping it fine and dry. differences in the amounts of cloud from day to day. we've got a few more isobars on the chart by monday in the south, so it's going to be quite windy here, i think, on monday, and quite a chilly wind coming in off the north sea as well. now, there may well be some cloud for a while pushing its way into england and wales. that will move through and away from northern scotland, there should be a lot of sunshine. so, sunny skies for england and wales but a cooler wind in the south, and temperatures on the whole will be lower in england and wales. we're starting to warm up again in northern ireland and particularly into western parts of scotland. a similar sort of scene, really, on tuesday. perhaps more cloud coming in on those brisk winds from off the north sea into central and eastern areas of england. the best of the sunshine in the west and the north and again, the highest temperatures are likely to be into the low 20s across western areas of scotland. again, west is best, i think, as we head into wednesday. there's our area of high pressure, not changing very much. more isobars in the south.

still that brisk wind blowing across southern parts of the country. this time, we may be looking at bluer skies. not much cloud around on wednesday but again, it's going to be cooler around some of those north sea coasts. highest temperatures in the west, reaching the low 20s once again — 22,23, maybe even a little bit higher than that where the winds are a bit lighter. now, looking further ahead, high pressure�*s still close by. it's not retreating quite as quickly but there is falling pressure in the south. that's coming from spain and portugal, across france, and it brings the potential next weekend maybe for a few showers across southern parts of the uk. but because the high pressure is not declining so rapidly and there's some warm air in that and coming up from the south, that colder air is not coming into the north—east of the uk quite so quickly. so, it looks like it's going to be continuing dry and warm with plenty of sunshine. temperatures could get beyond the mid 20s for

a while but we do have this caveat — there could be a few showers in the south next weekend.

three times more power than traditional lithium—ion ones.

live from washington, this is bbc news. the growing field of hopefuls vying for the republican nomination, with two launches in one week. who will be the biggest challenge to the leader in the polls — former president donald trump? and where do the candidates stand on foreign policy issues, like the war in ukraine? hello, i'm sumi somaskanda. welcome to our show. it's been a headline grabbing week in the increasingly crowded race for the republican presidential nomination,