thank you for joining us. the news continues on america informant what is the beef with climate change? at home on the free range the surprising risks to our environment posed by politically correct beef. are you telling me i'm contributing to more greenhouse gas than if i had gone and bought industrial meat raised in a factory somewhere?

commitment. just about everything we do as human beings krnts in-- contributes in some way to those emissions, even when we think we're doing the right thing for sustainablity. america tonight's correspondent in hudson river valley with the look aat the unintended consequences of healthier living. >> reporter: for generations eating in america meant eating beef, celebrated in ads by the beef industry. brief, it's what's for dinner. >> reporter: cattle are an american icon. this is the country of big beef herds and vast ranches. >> reporter: bought to the table by cow boys on the range. the cost of beef has come at a big cost. livestock production is one of the biggest contributors to greenhouse gas emissions. worse even than all the world's transportation combined.

the worst offenders are cattle. to find out why we met up with a professor of environmental physics who studies the impact of cattle on climate change. without question eating beef is one of the worst things you can do for greenhouse gas emission. >> reporter: in terms of eating for sure. >> reporter: how much worse is it to eat beef than pork or chicken? reporter: americans consume about 25 billion pounds of beef annually. to meet that demand 31 million cattle are slaughtered every year. the vast majority of which spend their lives on industrial feed lots fattening up on a diet of

corn and soy. in recent years some american consumers have turned away from feed lot raised cattle and instead have started opting for grass fed beef raised in smaller numbers on farms. >> reporter: how many are there?

constantly moving the cattle to allow the grass to regrow. we're not using any herb side or pesticides, or chemical fort liesers. the sun makes the grass grow, the cattle harvest the grass and fetter lies the-- fertilise the graph. >> reporter: make the choice between industrial raised beef and grass fed beef on a place like this, consumers would be going with grass fed. it pastes better. these animals are living, i would say, a better life for beef, for cattle. >> reporter: this woman appreciates jacky's connection with cattle. he grew up on a farm in israel. he gave up eating it when as a scientist he crunched the data and recognised the cost to the environment. grass fed cattle are far from

the solution to global warming and they may add to the problem what is called grass fed in the mid west was the single worst option in interprets of global warming. it was worse by a very comfortable margin than the economical industrial meat. >> reporter: how can that be? i'm somebody who eats meat and i consider myself an educated consumers and i ask for grass fed beef. are you telling me that i am actually contributing to more greenhouse gas than if i had gone and bought industrial meat raised in a factory somewhere?

increase your beef out put >> reporter: the problem comes from meth an. a greenhouse gas more potent than carbon dioxide. they produce more on grass because it makes them burden of proof. we don't have the-- burp. the bacteria, you have form entation and the end product is methane. >> reporter: it actually makes them ferment more an there's more burping. they emit about two-ish time more methane if they eat grass than this noxious diet. >> reporter: twice as much. yes. >> reporter: do they eat all day? reporter: doesn't grass fed as opposed to grain fed produce

more methane within the cow? reporter: his research is based on farms other than in the south-east or north-east, but he sees a significant croft to tilths grazing >> reporter: do you think if they moved towards a grass fed model, that that would help anything or just make things worse?

mostly in the arid and semi--arid west and it's kind of worthless. it produces very little. if you bring it to the warm and moist south-east, you may be able to do it. we know that you are able to do it. it will be at the collection of many other things that the states currently produce. try that one. >> reporter: cattle are big part of life here in the hudson valley. jennifer broken offers a-- brown offers a different solution. she runs the woodstock farm sanctuary which cares for about 300 animal, including cows that escaped from areas. look at this tail. >> reporter: the vast majority are slaughtered at half the weight. >> reporter: how many pounds is he?

pounds. >> reporter: she founded the sanctuary 12 years ago because she is opposed to the eating of animals any step shifting away from consuming an ma'ams and animal products is a step in the right direction. even if you're doing it for yourself, yourself and for the planet, those are good reasons to. i'm doing it for the animals. >> reporter: we're scratching the surface in terms of the animals that we're able to help, but they are amazing ambassadors for our mission to raise awareness about the polite of farmed-- plight of farmed animals and the benefits of a vegan lifestyle and help change the way society views and treats these amazing beings. >> reporter: this is elvis the be that as it may was door? --am bassador. yes. he is such a love >> reporter: is responsible to be a shall-- possible to be a responsible consumer and eat

beef? reporter: if you're telling me i have this one vice and i have beef, i'm not flying, i'm not driving, you know, and i take cold showers. okay. more power to you, you know next, a deep dive into the climate change agenda. what the fate of the marshall islands means to the world leaders gathered in paris. later, how one of the tiniest creatures of the sea may issue the loudest warning about a danger in our waters. on the website now, the college president in the hot seat. students vote no confidence in the leader of ithika college. find out what he has to say at aljazeera.com/america tonight.

on the second day of the u.n. climate change conference in paris, president obama met with leaders from the small island nations, the one most threatened by rising tides.

at the marshall island, those in a locked struggle to becoming the first climate change refugees. >> reporter: far in the south pacific the marshall islands ride low above the waves spread out over hundreds of miles of ocean. there is very little here that is not beach front. this is an island one road wide. on this side is the pacific and on that side there's the lagoon and there's not much in between >> reporter: for thousands of years these narrow ribbons have been safe and welcome homes to fisherman, farmers, explorers and canou builders. the biggest resource is the ocean and what connects us to the ocean is our vessels. the vessel, of course, is just like the vessel in your body. it brings life to your body.

so does our vessel bring life all over the marshalls. >> reporter: the irony is that their greatest resource now poses the greatest threat to their future. this lady lives on the island. it sits only a foot or two above the high tide mark. that used to be enough. not any more this is the place where we have king tides, this is one of the areas that it comes in. >> reporter: how how does the water get? reporter: king tides occur every spring when the moana lines with the sun to increase the gravitational pull on the earth' tides. in the last few years these tides have brought devastating flooding. >> reporter: when the last king tides came, they came roaring

over here? reporter: king tides an unprecedented three times last year leaving behind salt that has contaminated the earth, killing plant life and crops and poisoning the drinking water. >> reporter: tell me what happened here this is where our house stood. this is the bathroom area, the water tank was there. >> reporter: where was the front door? reporter: just took everything out? reporter: meryl is one of

the thousand people from the main island rendered homeless in flooding last march. she and her family are betting all that they have invested in the hope that global leaders will make the tough decisions necessary to keep global warming to less than 2 degrees celsius. that's 3.6 degrees fahrenheit. with those tough decisions, the seas might recede. the chief meterologist worries about the sea. we have seen a steady increase in the sea level around the marshall islands. >> reporter: is there any prospect that that sea level will decrease?

should recede. our prjection shows that by 2050 there will be a foot rise in marshall island. by 2090 at least a range of 16 inches to two feet. >> reporter: the residents of one remote island, life has already become unsustainable. one mile by one and a half miles long is this island. >> reporter: a tiny lump in the show an. -- ocean. yeah. >> reporter: this woman lives on magera but worries about her 90-year-old grandmother who remains on a small island. it was cut off from the outside world making evacuation impossible. in 30 minutes it came up to their knees and within the hour it was up to the waist.

next year when those waves come in, what's going to happen? she grandmother can't walk. she only crawls. who will carry her up and out when the waves come. >> reporter: what's it like for people like your grandmother an cousins living on keely knows that the waves will come and they will come to your waist and who knows how much higher? where do you go?

biggest warning about the danger in our waters. coming up at the top of the hour, more u.s. special forces are aheaded to iraq to step up the fight against i.s.i.l. iraqi forces backed by u.s. air strikes close in on the city of romaki. a second default for vw. marking world aids day, an update on the fight against miv is coming up in the next hour.

when we hear about climate change we think about polar bears stranded on iceburgs. one less seen is more in the oceans. in america tonight lisa has found it is threaten in the pacific e this is where we grow under controlled condition our lavae >> reporter: this man over sees what may be the world's most prolific nursery. on any given day hundreds of

millions of sea creatures begin life under his watchful eye. 20 million larvae per tank? reporter: he raises i sisters for the tailor shell fish company. it is the largest producer of shell fish in the united states. processing some 16 million oysteres evidence year. they begin life in tanks filled with sea water. the larvae so small they can only be seen by a microscope. they have little shells on them already when they leave here yeah. >> reporter: now his newly born oyster are under threat from ocean acidification.

it is a process that is one of the most serious effects of greenhouse gas emissions. nearly one third of the world's carbon emissions are absorbed by the ocean. some 22 million tonnes of co2 every day. >> reporter: what do those emissions to do the chemistry of the water? reporter: for juvenile oysters that could be lethal per centing them from forming shells. this website shows the problem. it projects by the year 210 owe

acidity will increase by a factor of 5. the shell would be dissolved in just 45 days. >> reporter: who know how far it goes, if it's affecting our oysters and what other species. >> reporter: do you think that is what you would be doing? >> reporter: her great grandfather first harvested oysteres in the 1890s. she and her cousin are now the fifth generation of tailors to work here. much like farmers planting a crop, they use juvenile oysters to feed these beaches. here they will grow into adults ready to harvest. according to the tailors ocean acidificaton has cost them dearly that meant that we didn't

have any oysters to plant on the beach. there was a period of time when they were dying off and you didn't know why? reporter: we're standing in an oyster bed that was farmed by your great, great grandfather. you must feel responsibility to this land. absolutely. it gives you a huge sense of pride but also a huge sense of responsibility to the places that we form and to make sure that we can farm them for another five generations. >> reporter: the tailors say if there's anything that five generations in the sea food business have taught them, it's to persevere through good times and bad. so they aren't taking this latest misfortune laying down they have decided to fight the issue of climate change head

on. she went to washington to lobe eau the government, looking for a practical solution to per cent oyster die offs. what we have here is today's forecast. >> reporter: this man is at the university of washington. we met him at the offices of the tailors. it's a model of ocean circulation. >> reporter: he has been working on i what way to predict daily changes to the acid level of the local water. this issue is not uniform everywhere. there are big differences near the surface or deep in the ocean >> reporter: are you optimistic that this will be a tool in a couple of years from now that they can depend on? reporter: harmed with legal time data there have been adjustments made as to how he raises the oysters.

treating his withdrawer we have a continuous ph instrument. >> reporter: can i look? reporter: you make this every day. kind of like you're adding tones to the water. yeah, very similar. that's what we are doing. >> reporter: while he believes this pioneering method is helping the survival of oysters, it hasn't completely eliminated die offs. larvae are again dying in large numbers. more research is being done showing that this part is more insidious consequences of co2 to the water we've been around for 120 and we want to be around for 120 years more but this is a global issue, something that all world oceans will have to deal with at some point. important to us, but it's

important to a lot of other people too and we just don't know all of the effects and what could happen >> reporter: so as one year old this one carrys the family torch into its sixth generation, the tailors hope leaders are paying attention so kids like nya has a legacy to preserve we hope she will. that's america tonight. tell us what you think at aljazeera.com/america tonight. talk to us on twitter and facebook and come back. we will have more of america tonight tomorrow.

and we show you like no-one else can. this is our american story. this is america tonight. expanding the mission. we're at war. we're using the light of the finest fighting force of the world between secretary ash carter says more u.s. to forces are heading to iraq to fight i.s.i.l. american sympathizers, a report on who is supporting i.s.i.l. and how the group lures its