the longest un climate talks ever held have finished with a compromise deal on tackling climate change. delegates and environmental campaigners called it an utter failure, blaming some of the most polluting nations for holding back decisive action. discussions on several key issues were shelved until next year's climate talks in the uk. activists are continuing their protests in the indian capital, delhi, accusing police of attacking students demonstrating against a controversial new law. it allows migrants escaping religious persecution in neighbouring countries to claim citizenship, but not if they're muslim. new zealand has held a minute's silence to mark the exact moment a week ago when a deadly volcanic eruption took place on white island. 18 people are known to have died in the explosion, including two whose bodies have not been recovered. 26 survivors remain in a critical condition. we are learning more details

about the british man who was shot and killed during a robbery in argentina. he is understood to be 50—year—old matthew gibbard, from northamptonshire. his stepson stefan zone is also thought to have been wounded. it happened outside a five—star hotel in the capital, buenos aires. here is our correspondent angus crawford. moments before a brutal attack in broad daylight. see the white minibus. matthew gibbard, stefan zone and theirfamily are inside. the driver moves to get their luggage. no—one notices the man on the motorbike. at the top of the screen, his accomplice attacks the tourists who fight back. what happens next is too distressing to show. it took place yesterday morning in one of buenos aires‘ most affluent neighbourhoods, outside the 5—star faena art hotel. mr gibbard died in hospital. mr zone, shot in the thigh,

is in a serious condition. the foreign office says it is supporting their family and helping the authorities. the attackers fled on a motorbike. police have made no arrests. a life cut short in a senseless act of violence. angus crawford, bbc news. now on bbc news: the black sea is europe's most polluted. but asjonah fisher finds out, thanks to a major international clean—up effort, there are now signs that the sea is starting to recover. the black sea is beautiful. it is a fantastic place, there are thousands of living species in it. some of them are very unique. in europe's south—eastern corner, there is a sea that, for decades, served as the region's dustbin. this is now a real problem, people are dying for that. fertilisers, industrial chemicals, raw sewage have flowed unchecked into the black sea, past tourist beaches, ruining fishing grounds. it would kill the black sea,

people would not be swimming in it, fish would not be living in it. it smells like rotten eggs. but having hit rock bottom, is europe's most polluted sea finally cleaning up its act? do you think the black sea is now on its way back? to understand the black sea's problems, look inland...

..to the rivers that fill it, reaching thousands of kilometres across eastern europe. aleksandr chistya kov has been monitoring the dnieper in ukraine for years. he's showing us what's known as blooming. it's when too many nutrients get in the water, triggering a rapid, lurid green growth of algae.

outside the cities, the run—off from fertilisers used in farming is also a big part of the problem. as is untreated waste. of course, if fertilisers and waste is dumped in the rivers, it means pollution when those rivers then flow into the black sea. three rivers provide the bulk of the black sea's pollution — the dnieper, the dnister and the longest of them all, the danube. back in august, the water quality reached the headlines in ukraine. a combination of rain and hot weather near odessa was turned into a nutrient rich pea soup.

anything that swam in it turned green. these women work for odessa's sanitation department and test the black sea every monday. this year, they advised holidaymakers not to swim through most of the peak month of august. not that it put many people off. you're not worried the water is not clean? no.

and when the authorities say the water is dirty, don't swim, do you stop? are you not worried that this water is polluted and it might make you sick? 1,000 kilometres away, on another very different beach, one of the black sea's most visible problems is piling up. this is batumi in georgia, a holiday boom town on the sea's far eastern edge. it's grown exponentially in the last ten years. but batumi has a dirty,

smelly secretjust one kilometre from its tourist beaches. so, this is the main rubbish dump here in batumi. obviously, it's pretty disgusting. you can see, full of animals scavenging off the rubbish, people too. the big issue for here is that it's only about 300, 400 metres from this rubbish dump to the black sea itself. and there's a waterway which basically leads all the way down there. taking the rubbish with it. having scrambled down onto the beach, we find some locals. he's caught a fish! are you going to eat them?

are you not worried that there's a rubbish dumpjust up the road? and this water might have come from there? a few metres away on the beach, rubbish from the dump is being washed up. so, there's rubbish all along this beach, butjust to give you a sense of part of it, what it's made up of, well, there's lots of plastic bottles everywhere. that's part of a light bulb. an inhaler. some sort of plastic brush, more medicine bottles that looks like. and over here, lots and lots more plastic bottles. some sort of margarine container, a shoe... really depressing and grim

to see it like this. because this is just a little snapshot here, but it goes all the way on in a pretty similar way to this. poor waste management and rubbish dump along rivers have turned the black sea into europe's most polluted. the latest survey shows a concentration of litter in the sea almost twice as high as in the mediterranean. for years, there was very little detailed information about the state of the black sea. copper pots. that is now changing, and we have joined a research vessel funded by the european union. packed full of scientists, its job is to travel right across the black sea, providing the data to better inform government decisions.

long before humans began ruining the black sea, it had, thanks to its geography, a unique makeup. 89% of the total body of the black sea, it's not this beautiful, blue water with jumping dolphins here and there, but it's hydrogen sulphide, toxic, smelly chemical. so when you go down, 100, 150 metres under the surface, forget life, you know. bacteria is there. what's worrying scientists is that climate change might lead to a shift in the delicate balance between the two layers. one of the many unknowns about the black sea is how climate change and rising sea temperatures will affect the oxygenated layer at the top, and the hydrogen sulphide below that. now, this device here, well, these tanks will take samples of water at different depths, and the sensors beneath here,

they're designed to measure the temperature, the salinity and the oxygen content of the water. that allows scientists to say at what point in the water, the oxygenated layer ends and the hydrogen sulphide layer, that dead zone, begins. as the device is lowered, it sends back its readings. oxygen minimum on this location, about 88 metres. so, the hydrogen sulphide layer starts at 88 metres here? ah...about 90 metres, yeah. what would be the impact for the black sea if the hydrogen sulphide layer rose up? it would kill the entire black sea, people would not be swimming in it, fish would not living in it, no plant would be growing

at the bottom of the sea. at the moment, the data suggests that the oxygenated layer that supports life is getting squeezed. but there's not enough evidence yet to make firm conclusions. so, the water from the different depths is now being removed and ta ken away. it will be analysed and looked at very closely for traces of plastics, pollutants, organic matter. all helping the scientists here to get a better idea of how healthy or unhealthy that part of the black sea is. the same painstaking process is repeated at 12 different sampling sites over the course of seven days. but to get an idea of what's going on on the seabed... you need a different piece of kit. we're now at one of the deepest

parts of the black sea, and if you want to find out what's on the bottom here, you need to use a tool like this. this is called a multi—corer. the way it works is it's sent down over the side and then it will hit the bottom and sediment from the bottom will be gathered up in those plastic tubes there and brought back up to the surface. the middle of the black sea is more than two kilometres deep, so it takes more than half an hour for it to reach the ocean floor. ok, so it's now hit the bottom. the reading is about 2,200. the muddy sludge gathered is winched back up to the boat. this sample has come right from the very bottom of the black sea, the part where there's no oxygen, the hydrogen sulphide layer.

oh, the smell. smell is chanel. you think it's chanel? black sea chanel. it's more like rotten eggs. samples taken from the bottom at sites hundreds of kilometres from the shore have shown the extent of the black sea's contamination. micro plastics are tiny pieces of plastic which can be swallowed by marine creatures and thus get into the food chain.

the study of micro plastics is relatively new so it's not clear yet what impact ingesting them will have on our health. to get good samples of the surface seawater, i leave the main research vessel with peter oswald, a slovakian scientist. peter tells me he has been finding tiny traces of everyday items in the middle of the sea. stimulants like caffeine, illicit drugs, painkillers, stuff like ibuprofen and then there are compounds coming from personal care products, from shampoo and dishwasher detergents and so on. that sounds horrifying. should we worry about this? the biggest threat is

from pharmaceuticals, especially from antibiotics. the problem is the bacteria, which are also here, can get resistant against these antibiotics and this is the biggest problem. and that is because if there are antibiotics in the black sea, that means the bacteria will develop here that will resist the antibiotics and mean that, ultimately, that medicine doesn't work anymore. this is now a real problem. people are dying because of it. because the bacteria is resistant? yes, of course. after a week at sea, we left the ship, having received a bleak lesson in just how badly humans have damaged the black sea. faced with the piles of rubbish and the contamination, it would be easy to write off the black sea as beyond help. plastic bottle, plastic bottle... indeed, if we'd made

this film in the 1990s, we would have probably stopped here. but thanks to a concerted international effort, this isn't the end. this is the river danube. it is one of europe's longest and most polluted rivers. it stretches its way almost 3,000 kilometres across south—eastern europe before emptying into the black sea. it's also a source of hope because over the last 20 years, the danube has been the subject of a massive clean—up operation. and it appears to be working. so, this is basically a river of human poo. yeah. if you flush the toilet in budapest in hungary, there's a good chance it'll end up here. wouldn't recommend swimming in it. completed nine years ago,

this is part of a water treatment revolution along the danube. backed by millions of euros of european union money. before this plant was built, around half of the produced waste water was going directly into the danube. raw sewerage? and after we had this one, after 2010, almost 95%, 96% of the whle sewage is treated, biologically treated and going like this, clean, to the danube. eu membership for countries like hungary, that the danube flows through, has meant cash for treatment plants and stricter rules on what industry and agriculture can put in the river. those in charge of monitoring say it's made a real difference. the eu provided a framework where the combination of the regulatory frame

of the regulation and the transfer of the money that finances support to the new member state was one of the key factors of the improving of the situation on the danube. so, this is a positive story. you're sure that the danube and, by connection, the black sea are now on their way back and the worst is over? we can be happy and satisfied with what we did in terms of reduction of pollution coming from one big river, which is danube, because we do not know much about the other rivers. but definitely over the last 15 years, we've witnessed improvement. the whole danube story is a success story of the countries transforming themselves in an better environmental management and in reaching a better environmental situation. in search of those signs of recovery, we headed off into the shallow part of the black sea, near to the mouth of the danube. one of the best indicators as to whether things are getting better is the presence of this

red seaweed, called phyllophora. large phyllophora fields were once common in this part of the black sea but as the water quality deteriorated, the seaweed fields shrunk dramatically. alexander is heading a0 metres down to the bottom of the black sea to look for signs that the phyllophora is indeed on its way back. his underwater camera shows lots of jellyfish. they're an indicator of poor water quality

and a sign there aren't many predators that might eat them. if there's lots of seaweed, then there's food and shelter for small marine creatures too. back on the surface, alexander gives his verdict. oh, there they are! and what of the black sea's larger mammals like the dolphin? how many do you think there are there? how many? yeah.

ah, at least seven. karina, a dolphin expert, is taking part in a major survey to try and find out if their numbers are recovering. so, there's a group of dolphins that keep surfacing near where we are and we are trying — there they are again — we are trying to take good pictures of their fins because dolphins have unique markings on theirfins and if we can get a good picture of the fin when it pops above the water, then it's possible to track and see if it has been seen somewhere else in the black sea. we have something like this. and you see, the dorsal, the back fin is quite sharp. yes, it's got... it has scars or a cut on it. so that should help you match it and see if you've seen it anywhere else before? yeah. there are two species of dolphin in the black sea. but at the moment, no—one knows

how badly they've been affected by all the pollution. though its overall condition remains grim, this is not a story without hope. the black sea does appear, thanks in part to efforts along the danube, to have turned the corner. in very, very general terms, then i would be putting it in one sentence is that the black sea is recovering. for those who despair that humanity is incapable of rising to the scale of the global environmental crisis, the black sea is an example of how,

with sustained effort, a seemingly endless tide of destruction can be slowed and just, maybe, turned. hello there. after some heavy overnight showers and plunging temperatures as well, we go into the new week on a bit of a wintry note for some of you. but gradually through this week, we are set to see temperatures rise a bit more widely across the uk, but the pay—off, during the second half of the week, is wetter and windier weather is set to return once again. but let's kick off with what's happening on monday morning. a chilly start, as i said, some showers through the night, that left a covering of snow. and anywhere from wales, the midlands, northwards, temperatures will be low enough for some slippery conditions on roads and pavements, particularly northern england

and central and southern scotland, where there could still be some wintry showers, giving a coating of snow over the hills. through the day, western scotland, northern ireland, the showers become more frequent than saw during sunday, with stronger winds. further south, well, a few showers around. one or two will continue towards the south—east, and around some eastern coasts and hill through the day. but overall, a drier afternoon, bright afternoon, and less windy one. temperatures, though, will be the same as we've seen through the weekend, around 4—10 degrees. and the second the sun sets, they will plummet away. it's going to be another chilly night. a few things continuing, though, through monday night. showers in western scotland, northern ireland, giving further covering of snow across the grampians and the highlands, but something cloudier and wetter spreading in through the channel islands, towards east anglia and the south—east, keeping temperatures up here. away from that, though, a risk of frost, some ice and a greater chance of some fog patches into the tuesday morning rush hour. so, a few things for tuesday to consider. cloud and outbreaks of rain in that south—east corner could continue all day long, eventually easing. there'll be fog to begin with elsewhere. that will gradually clear. a few showers dotted around in the north and the west, more especially towards shetland.

many, though, having a drier day, but quite a chilly one. after that cold start, temperatures only around 4—8 degrees during the afternoon. and a cold night will follow with widespread frost and the return of some fog patches. this little bump here is a ridge of high pressure keeping things dry to take us into the start of wednesday. if you avoid the fog patches on wednesday, then you've got a lovely bright, crisp, sunny start to the day, with light winds. but through the day, the breeze will be picking up in the west. northern ireland, wales, south—west england will gradually turn windier and wetter. temperatures will be on the rise into double figures by the end of the day. but much of scotland, northern eastern england, a chilly day with some sunny spells. here, though, we'll see the rain arrive as we go through wednesday night and with a big driving area of low pressure out towards the west of us, southerly winds will keep temperatures up. no frost to take us into thursday morning but we could see a spell of snow before that turns back to rain across the grampians and the highlands. some blizzard conditions for a time. that clears its way northwards. thursday then, a story of sunshine and heavy and thundery showers.

quite a breezy day as it will be on friday with more rain for many of you. but as i said, temperatures will be on the up.

welcome to bbc news, i'm james reynolds. our top stories: marathon talks on climate change close in madrid, but a compromise deal prompts scathing criticism. we will never accept crumbs of a future, and we will make the polluters pay. this cop has failed the people and the planet. indian police confront demonstrators on the streets of delhi as protests over a new citizenship law intensify. running battles in the lebanese capital, beirut. thousands of anti—government protesters clash with police. and putin's 20 years in power.