>>...have an organized right-wing movement trying to kill others. >> searching for a strategy. if we win it with a large arab force, the turks, and the egyptians and other sunni nation, and go in there and take those people out... >> congress demands answers and offers suggestions for the fight against i.s.i.l. the other i.s.i.l. threat. >> abu bakr al-baghdadi, the leader of i.s.i.s. is now focussing his energy on libya. >> why the fight against the group may have to shift beyond

syria and iraq. opportunities apiece. >> we are entering a transitional phase. f.a.r.c. rebels deep in the jungles of columbia. an atmospheric alternative. while the talks on reducing climate change. scientists are working on other solutions to fight climate change. good evening, i'm antonio mora, this is al jazeera america. we begin this international news hour with a debate on capitol hill. today the senate grilled top obama initiatives about the strategy to fight i.s.i.l. we have this talk on the contentious exchanges. >> at the senate committee, fbi

director james comey singled out i.s.i.l. as the biggest terrorist threat facing the united states. >> their ability to have a safe haven from which to gather resources increases the risk of their ability to moulent a sophisticated attacks against the homeland. . >> over at the armed services, senator want to know if i.s.i.l. is a big threat. why is there not a big effort to wipe it out. >> we want to know how to do it. ash carter - joint vice chairman george silva could offer a time line of when i.s.i.l. could d cleared out of the time line. >> i'm orchestrating an attack. the fbi says so far there is no indication that i.s.i.l. ordered the attack that killed four in

california. they are searching for fighters, pleading with countries in the region. we wish that particularly the sunni arab nations of the gulf would do more. and going way back, they are willing to do so. i've had lengthy conversations. >> and so have i. >> reporter: the latest retired commander to weigh in with a small numbers to lead an international force is former army chief and commander general ordinaro. >> what a better time to build a coalition with the european allies, partners in the middle east, to put a force in to defeat i.s.i.s., with u.s. leading or some u.s. troops involved. >> the armed services committee chairman says he's right. >> if we went in with a large

force, turks and egyptians and go in there and take people out, there's 20,000-30,000 of them. they are not giants. >> secretary carter did say the u.s. would be willing to send in attack helicopters to help iraq take i.s.i.l.-held ramadi. >> we have not recommended it, because of the political situation on the ground and the potential for loss of american life. it's one of the more embarrassing statements. that we are worried about syria and russia's reactions to saving the lives of thousands and thousands of syrians that are massacred so far, a remarkable performance. >> joining us to discuss ash carter's comments on i.s.i.l., is doug ollivant, director for

iraq at the national security council. he joins us from washington. good evening, doug. >> evening, how are you. >> good, thanks, as jamie mcintyre put it, if i.s.i.l. is the biggest threat to the u.s., why is there not a bigger effort against i.s.i.l.? >> well, i think part of this is what we saw in the comments today. senator mccain saying that we could send turks. if we send the turks over the border. the kurds will shoot at them. this is complicated and much as i head to admit it, i'm a little sympathetic to the witnesses today. everyone is looking for a simple answer for a simple bullet. and this is a difficult problem. >> as a result, as you know, we cover the story every night, you and i talked about it ad nauseam and i'm confused. the defense secretary and analysts, including you argue

that we need sunni forces from the region to defeat i.s.i.l. carter says indigenous arab forces are not ready to take on i.s.i.l., and allies show little interest to distribute troops. if that's the case. what is the territory. >> that is true. the gulf states are more interested in fighting the fight in yemen than they do in contributing anything to the i.s.i.l. i.s.i.s. fight. which is a real problem. you know, you have to kind of cans with who you've got. in this case that really is the iraqi forces, fairs flavours phone air side, and trying to put together something on the syrian side of the border, which we are still really struggling with. >> that, i would say is an understatement. it's gone nowhere, and carter said that allies were not interested in cricketing troops even if the u.s. sent more

troops. senator mccain argued that was not the case that if the u.s. had a bigger commitment, sunni troops from the region would follow. who is right? >> i think in this case the defense secretary. >> the sunni states can't generate forces to go to yemen, which they really care about. they are reduced to hiring columbian mercenaries to go to yemen. the idea we'll get ground forces from the sunni states to fight against i.s.i.l. is fantasy. i'm not sure where that is coming from. we had some news today from the secretary carter. i think his administration, we would be willing to use an apache attack helicopter to assist the iraqis. >> that is news. >> we heard today that the u.s. is willing to support forces in retaking ramadi. iraqi forces have been fighting for months, they have made

progress. they now control half the city. here is the question i if asked you before. president obama has been debating using apache since june. why wait until now? >> only now is the ground forces of the iraqis in a position to get synergy with what the apache helicopters can do. we could have sent apaches months ago and have them take out targets in ramadi, but there would have been nothing to exploit the games, nothing to take advantage of what the apaches were doing, now with the iraqi forces knocking at the door, if the apaches are taking out key targets, the ground forces can take advantage of that. >> it teems they financially have been making some progress there. good to have you with us. >> thank you.

that's a good news story. >> turkey says russia's bombing campaign in syria has nothing to do with fighting i.s.i.l. the turk your prime minister is accusing them of ethnic cleansing. russia is targetting the communities along syria's border. the last opposition fighters and sympathizers left the city. it was the final step in a u.n. brokered deal giving them safe passage in a rebel held area further north. the conflict opposed so many groups that it's complicating the path to peace negotiations. the british ambassador for the unsays diplomats are working to figure out who the opposition is and who the terrorists are. both terms need to be defined before meaningful peace talks can take place. a threat kept the u.s. consulate

in istanbul closed. there was no attack. the outpost will likely reopen thursday. they never said what kind of threat caused the closure, but they are cautiousing them to be vigilant. the u.s. consulate remained open on wednesday. >> authorities in paris yoiffed the third place that took part. police named the gunman, part of the group that silled 90 people. the 23-year-old was born and raised in france, but spent time in 2013, 2014. he was identified after his mother received a text message saying her son had died a martyr. in afghanistan, at least 70 civilians and afghan security

forces are dead. an attack in kandahar, a siege tuesday might at a heavily protected base. afghan officials say taliban fighters breached the perimeter of the compound. they took families hostage and used them as human shields. the siege lasted 24 hours. all 14 were killed. in iraq i.s.i.l. claimed responsibility. at a shi'a mosque. an interior spokesperson said the attacker ex-itied the attack. the attack as the iraqi forces are preparing to push into the center of the i.s.i.s.-controlled city of ramadi yemen's president says a 7-day ceasefire has a chance of being renewed if houthi fighters honour its terms. the saudis asked for the truce

to be started on december 15th, the same time u.s. sponsored talks in geneva begin. unknown attackers blew up an abandoned catholic church in the southern port city of amen. saudi-led forces expelled the houthis. the i.s.i.l. threat in libya, coming up next. i.s.i.l.'s full back in case it's defeated in iraq. after a year dealing with the greek debt crisis and the flood of refugees into europe. a special honour for german chancellor angela merkel.

according to a united nations report i.s.i.l. has several thousand fighters in libya and seized the country as a recruiting zone. the u.s. is targetting i.s.i.l. leaders in libya with air strikes in an effort to stop the group's expansion. defense secret ci ash carter revealed details in a hearing. we are improving capability on leadership. we have removed two more i.s.i.l. figures from the battle fig. jihadi john, an i.s.i.l. execution ear. and i.s.i.l.'s leader in libya.

>> in the chaos of libya, i.s.i.l. is trying to cease ground. it has between 2,000 and 3,000 fighters, and more than 800 libyans that returned to the site. i.s.i.l.'s central leadership sees libya as group four and staging attacks. i.s.i.l. may have problems. unlike iraq and syria, it is a sunni county, so i.s.i.l. may not be able to capitalize on sunni visions. certain areas in the town is the group's strong hold. the port city sits between the two rival governments in cities 750 miles apart. as peace negotiations between the two governments grine on and off, i.s.i.l. launched attacks as far away as tripoli. an attack killing eight in .

the group released a video showing i.s.i.l. fighters killing more than 20 coptic christian oil workers. members of the u.n. security council condemned the kill of 30 ethiopian christians. the slogan translates as remaining and expanding. with territory referred to as its cal fate, the group is determined to expand across the middle east and north africa. this is a best selling author who wrote on the arab world, a professor of middle east studies at the london school of economics, and joins us from london. good to see you. public beheadings, crucifixions, i.s.i.l. is extending a rein of

terror through a good portion of libya. the u.n. report says abu bakr al-baghdadi sees libya as the best opportunity for i.s.i.l. how far are we from the point where libya looks like the two countries. >> outside the city and iraq. i.s.i.s. is the only place where it controls territories. it controls almost 150 miles of sea lanes. it has between 2,000 and 3,000 fighters. abu bakr al-baghdadi and the i.s.i.s. leadership have been sending others to run the affiliate. it's the most active, prominent. you have chaos in libya, warring governments. we know about i.s.i.s. and al qaeda. they are nourished in conflict zones, and libya is an ideal

place, and that is why the united nation and the libyans and the international community are anxious and concerned about the emergens of this i.s.i.s. affiliate. on the other hand, as the story pointed out. as opposed to what is happening in syria and iraq, what is the reality, there is no sunni divide that i.s.i.l. can exploit in libya. will that hurt its chances of expanding. >> you're right. >> there is no sectarian all-out war in libya. we have a chaotic situation, there's no centralized government. there are no institutions, there is no army, chaos, letterally chaos, remember the borders. west africa.

keep in mind. there's regional war by proxies. i.s.i.s., basically as we know from iraq and syria knows how to exploit the regional war, and more importantly you have oil and gas, extracting taxes, controlling oil resources and we wonder why background, the leader of i.s.i.s. is focussing it on libya. just in case, the pressure is on, is on the defensive. the americans are putting forces to cease iraqi. the capital of i.s.i.s. with syria. that's where abu bakr al-baghdadi and his planners are investing major resources turning libya into a major foot

hold. >> and there in north africa it's 300 miles from cert to sicily. they were warned that in libya, there is the perfect mix ready to explode and in case it exploded. it would explode the gaits of europe. we exploded it, how serious a threat would a strong area be. >> we focus a great deal of the west as we should. if abu bakr al-baghdadi and his planner succeeds in tranching themselves in libya. libya could be a major ticking bomb for north africa. west africa. this is where the threat it, to tunisia. think of where the threats is. they terrorize the state. they have waged a campaign,

warfare against tunisia. lot algeria and morocco. they have the capacity to attack italy. as you said 200 miles way way from sicily. and the question of terrorism and migrants. and this is basically a lethal combination. >> how problematic is the northern half of africa with i.s.i.l. and egypt, chad and cameroon. al qaeda and the islamic, mauritania and all these attacks in tunisia. the list goes on and on. >> it's really a serious epidemic. i mean i said of syria and iraq, i.s.i.s. has eight affiliates in egypt. one of the most active. what is unique, it is

controlled. the affiliate is controlled by the centralized leadership in syria. this is unique. of course you have boko haram, al qaeda and it tells you about the gravity of the situation. it tells you about the expansion. we keep talking about i.s.i.s. the threat is much greater. the rivalry between i.s.i.s. and al qaeda is also poisoning the situations in many countries. yes, there is a real danger to the west, to italy and european countries. let's keep in mind that the real threat it to really north african countries, to west africa. >> is libya a failure of u.s. and n.a.t.o. policy. they bombed to get rid of muammar gaddafi. allowing the country to send into anarchy.

should it gr intereen in lib -- should it intervene before it gets worse. >> you are raising a big question. we would not have i.s.i.s. if it was not the american invasion in 2003. i.s.i.s. is a direct product of al qaeda, and iraq. that existed after the u.s. led invasion and occupation of iraq. i mean, n.a.t.o. and the united states did not even think about the alternative. they basically toppled charles godfrey, and went home. you have chaos, warring factions, militias. eted mick tribal militias, and reasons by proxies in before. you have ooesha. the united arab empire. here is i.s.i.s. and al qaeda. you have a perfect situation.

we have chaos whether it's al qaeda and afghanistan. or i.s.i.l. in syria. basically these non-state extremist groups are nourished in conflict zone. they are social parasites. and the question is where do we go from here. you need to basically help reconcile the government. one in tobruk in the east, one in italy. you need to help begin the process. a centralized government, an army. you need to mobilize the libyan people. if i.s.i.s. or i.s.i.l. succeeds in establishing a major base in libya, libya would not only become a failed state. basically it would be truly a state that would export terror to its neighbours near and far. >> a lot to worry about in

libya. always a pleasure to talk to you. thank you for your insights. >> thank you for having me, antonio. >> president obama welcomed israeli president rivlin to the white house, they joined guests at a hanukkah ceremony. he had been a strong voice. they discussed renewing a security agreement that could lead to military assistance in israel. >> after life on the run in the jungle f.a.r.c. rebels are preparing to live in peace in columbian society. >> the complicated legacy of outgoing president cristina fernandez de kirchner.

>> we are scared. >>...have an organized right-wing movement trying to kill others. welcome back to al jazeera america i'm antonio mora, coming up in this half hour of international news. sharp reaction around the globe for donald trump's call on a ban to muslims. first a look at the headlines across the u.s. - a suspect accused of the killing three people at a planned parenthood

called himself guilty and a warrior for the babies. robert lewis deer had several outbursts in court and the judge ished a gag order after it was requested -- issued a gag order after it was requested by deer's lawyer protests demanding the oust or of the mayor. rahm emanuel said he is not going anywhere and apologised for the police handling of young black men and promised to fix the situation. >> no child left behind - it's being replaced. a new law allows for states to have more control. it does away with the common core curriculum. the legislation proists more money to help disadvantaged children attend preschool. >> after 50 years of conflict, there's high hopes of peace. the columbian rebels are in the

final stretch. lasting decades. killing more than 200,000 people. in the in-context segment we look at how generations of rebels are preparing for life. we have this report from eastern columbia. >> f.a.r.c. fighters exercising at dawn, their rifles in hand. but nose gathered in this camp were not here to practice how to fight. >> it's time to start an education offensive, including a literacy campaign, mathematics, political guidelines, philosophy and bol varyian ideas. this man leads the class, part of the high comment of the f.a.r.c. eastern bloc. a strong faction of the group. he tells the rebels about the change in focus. >> recently f.a.r.c.'s commander orders ammunition and

explosives, the priority, preparing these rebels for civilian life. >> for the past three years f.a.r.c. have been holding peace talks in havana with the columbian government. while the conflict on the ground continues. the rebels dlarted a uni latter -- declared a unilateral ceasefire. nonetheless, government jets flyoverhead. ending this class and sending them to their trenches. factor rebels have been at war with the columbian government for 51 years. successful military fifference and mass desertions reduced their numbers. one of the f.a.r.c. pieces were sent back to lecture them on the agreements. >> we are entering the transitional phase which the

government calls post conflict, and we call national organization. here he is discussing the joint deal to find 25,000 people that disappeared in the war. many of the fighters need basic education. they often appear in the war. and might soon have to find regular jobs. we are convinced that this time is a real possibility to reach a political solution. that is something that develops plans, plans that have nothing to do with weapons, war and military activity. >> these may hardly be enough to prepare all the rebels for what would cox. it shows that f.a.r.c. is serious to help life-long fighters to leave the jungle and weapons behind

a latin american analyst with the intelligence company, joins us from austin. good to have you with us. two big questions right now are facing columbia, one is will there be a final peace deal to end a longest and bloodiest insurgency in the americas. the second is whether the column by jan people will approve that deal. it seems f.a.r.c. wants more concessions from the columbian government. do you think in the end we'll see a deal? >> what is clear over the last few months is that we are in the final stages of a peace agreement, that the negotiations are all leading towards a potential peace agreement in 2016. one of the clearest signs of this is in the past month, the president said that there would be a specific date by which the government intends to finalise the signing of the peace accord,

that is to say an agreement after which the demobilization of the f.a.r.c. can begin. and an irony is that the f.a.r.c. opposes it on the left. but so does former president reba and his party on the right. >> definitely. there has been a push back. it wasn't enough to stop some of the preparations for the peace agreement from being approved. but there is push back from the right. of course, you have to remember that this was one of the staunchest opponents and it was under his mandate that some of the security gains were made in columbia allowing a discussion to take place. >> pundits of the deal argue that riva, f.a.r.c., is getting away with murder. it is getting minimal punishment. how big of an issue is that going to be? >> transitional justice is key

to demobilizing the leadership. accessing such courts and not tried was a key negotiation demand, particularly of the f.a.r.c. leadership. will everyone access the transitional justice courts? most likely not. the f.a.r.c. leadership and other members of the forkthat were in positions of command will likely get to confess the crimes and receive a pardon. however... >> talking about that kind of confession and reconciliation, steps towards reconciliation, from what i'm reading are difficult. i read stories about the f.a.r.c. apologising to a village, hitting a church in that village, killing almost 80 people. it didn't seem like the villagers were inclined to forgive. >> yes the issue of compensation to victims is understanding. there'll likely have to be a deal set, whether it's financial

compensation or recognition of the victims, as part of a peace agreement. there'll have to be steps taken by the f.a.r.c. to mend things, mend fences with some of the victims, that will be a long process. this is a multifaceted war. there were many actors in this. >> columbia made great strides in general. especially since uribe went in and did what he did in his years of power. there's still another group out there, and all sorts of criminal organizations and issues with drugs still. >> yes. very much so, we expect columbia to remain a drug production and trafficking hub. really for the for seeble future. the purpose was not to clampdown on drug trafficking, criminality and drug trafficking and production related violence, it was to reduce the number of

threats that the columbian state faced. you might see other groups remaining involved in a fight, remaining involved in criminal activity. >> quick final question for you. columbia is a different place than it was in the 1990s. >> oh, yes. columbia has made massive security gains in breaking apart some of the major drug trafficking organizations threatening public order and replacing the writ of the state in large parts of the country. as you have seen after the death in 1990s, and the break-up of his criminal organization into their smaller constituent parts. the threat they had has been reduced. in their place they have seen numerous organizations popping up. throughout the # '90s, and twr. the f.a.r.c. filled the void

that the groups left. >> reggie thompson, thank you. >> victoria's opposition lawmakers have been recognised. the opposition coalition won sunday's election declared a two-thirds majority. cristina fernandez de kirchner formed the last public act. the government house - cristina fernandez de kirchner has been criticized for refusing to attend. attending her inauguration, which would be the first time history, the first time it took place. venezuela, the populist policies. and the corruption are being scrutinised. >> the combative style warned

enemies. after eight years in power. cristina fernandez de kirchner is stepping down as president of argentina, and her legacy will be debated as much as her years in power. >> if there's something i'm proud of, it's we have come to repair and re-establish rights without different rights for everyone. cristina fernandez de kirchner became argentina's first elected female president following the government. together they gree aid a populist movement within the party centered on the presidential couple. nationalism. a strong influence on the economy has marked her years in office. >> human rights, social includes, we are owners of the economy. it's different. >> these people say cristina fernandez de kirchner made him believe in politics against,

because she brought justice to argentina. during this government, the perpetrators of human rights abuses, in the 1970s, and '80s, were put on trial for killing and torturing thousands of political opponents. >> there are thousands who continue to support her. many say she has done more damage than good. >> september the 10th we have the president and the vice president who are leaving. who are investigated for money laundering. cristina fernandez de kirchner has been close to foyer. as wife as a powerful governor. the role continues to bedebated. >> she said she is going to be with the people supporting them and challenging them if they do

something wrong. i don't see them retiring and leaving the ordeals behind. cristina fernandez de kirchner, has been a polarizing figure. many will celebrate the leaving. others will wait for her to return joining us tomorrow night when we look at the shifting politics of south america taking a closer look at the forces in the region. german chancellor has been named time magazine person of the year. she is the fourth woman since 1927 to be chosen. they praised her for how she managed the refugee crisis, and her strong response to russia's annexation of crimea and ukraine. one the other persons of the year is none other than donald

trump. this stirred debate across the u.s. the rest of the call it banned muslims, causing a stir. the mayor of london says he's out of his mind. >> i would invite him to see the whole of london and take im around the city. sent i wouldn't want to expose londoners to a risk far from inviting him to visit. 350,000 signed a petition to deny trump entry. in france the the prime minister accused trump of stoking hatred. >> i would like to affirm a message of support to the muslim compatriots. the state must protect our compatriots. and fell citizens that are muslim. to avoid the mixing up much things, in the atlantic and our own country.

>> the iranian president weighed in on trump. >> some people show up and they say muslims can be banned to enter the country as a way to fight terrorism. they are the ones that created terrorist. they have sown the seed in this region at their own expense. hassan rouhani's take on trump echo's others. the ban might farm the fight against i.s.i.l. and other groups. >> this marks the 50th anniversary. it bids discriminations on the grounds of colour, race, ethnic origins. jonah hill looks at whether the act is working and whether britain is more inclusive than it was. a forum for black entrepreneurs. 50 years after landmark race and

some find it exists. it is behind closed doors. whilst people are concerned the position is the same. >> the race relations act transformed britain, a country or empire that attracted migrants looking for work. prejudice based on colour became the norm. riots in the overcrowded suburb of noting hill. >> they have houses they want to live in. blimy, they are going to stay. that was a shock and is it brought the issue to the surface. >> veteran race campaigner trevor phillips. we don't have great equality. let's bear in mind this is a

different country to the one that my parents came to, where you could say what you liked about people. you could exclude them from phones and jobs. you can't do that today. if nothing else, that legislation changed the mood and sentiment. the streets of notting hill. things don't get more contrasting than this. home to the uber rich, the slums long gone. the stain of racism remains. race has played a part along with poverty and social exclusion in riots taking place in every decade since, and one of the authorities of a report on equality says existing legislation doesn't go far enough. there's less over racism. people are less vulnerable to people being beaten up and killed. there's covert racism. you have to send in twice as

many cvs, if you have an issuar african sounding survey. if you look at stop and search, black people are six times more likely to be stopped by the police. these are areas where black and ethnic minorities don't have equal outcomes. another change is that the problem today extends beyond black and white. in multiethnic modern britain, competition crosses colour lines, stretching tolerance to the outer limits still ahead on al jazeera america christmas controversy. coca-cola's holiday themed commercial in mexico stirred up an angry response. and the technology developed that could counteract climate

change. change. the coca-cola company has had some remarkable success with its bubbly advertising campaigns, including this famous one from 1971. [ ♪ ] the company's christmas advertising in mexico fizzled. john holman explained. >> >> reporter: coca-cola meant this to be a christmas ad for mexico, white hipsters putting up a tree, and handing out cokes to dark skinned. it was meant to inspire unity and joy. it's inspired fury online and a complaint from the rights groups saying it was racist. >> they had two types of people, people that are happy, that are

white, that go to the indigenous town, and they gave happiness with coke and christmas. and the people from the community only is passive. the backlash is so great. coca-cola pulled the commercial. this is part of a statement they sent us. in 19 years coca-cola mexico worked at sending and building a society free from prejudice. we lament that the message has been miz interpreted. the reaction may be a surprise, from the times of the spanish conquest stlo to the popular soap operas, dark skinned mexicans have been portrayed as subservient to whiter skinned mexicans. people in the town featured in

the commercial told us they were happy coca-cola came. they are among those that featured in the ab. >> when they took it down, i was disappointed. people were saying things that were not true. they said we were humiliated. >> coke is easily mexico's biggest selling soda. even as diabetes and obesity rates soared. it will take more than a suspect advert campaign to effect its appeal here. >> the first cane aidan government chartered flight is set to land in toronto on thursday. processing immigrants to canada is under way in several countries across the middle east. under the programme 25,000 syrian selected by the united nations refugee agency will be

resettled in canada by the end of february now the global news segment. at look at how news outlets are reacting to various event. the hindu takes on trump writing - trump could bin a nomination, but good hand the democratic opponent the keys to the white house. who is at stake is whether america becomes a source for extremists and chicago mail shows dr franken sign experimenting on the statue of liberty. >> and the statue of liberty trump extolling virtuous: negotiators at world climate talks in france released a draft agreement. it leaves issues unresolved.

including who would pay to help vulnerable nations pay for global warming. the u.s. is prepared to step up. he urged documents to reach an agreement by friday's deadline. >> unless the global community takes bold steps now. transitioning away from the high carbon economy. we are facing harm to the habitat, food production, water supplies and potentially to life itself. >> kerry announced the u.s. would double the amount of aid it gives to developing countries to adapt the climate change to 900 million a year. congress would have to give its approval. the focus of talks is on cutting emissions. scientists are working on new technology. tarek baysly looks at the pros and cons of geo-engineering. >> at no time in the last

800,000 years, longer, have carbon dioxide levels been as high as it is today. the greenhouse gas comes from human activity, trapping heat, resulting in a steady rise in temperatures, and what we can see here, warmer oceans. >> if we can't reduce our emissions of co2, scientists suggested other ways of looking at global warming. reflecting issues back into space results in a cooler earth. one idea is to brighten the clouds by spraying salt water into the sky. there's no evidence to suggest it would have a significant impact. >> another expensive idea is to replace reflective mirrors in orbit to block the sunlight. a third technique takes its queue from the volcanic eruption, resulting in

20 million tonnes of carbon dioxide being released into the atmosphere. it cooled the earth by half a degree. purpose fully sprayed, sulphur dioxide into the upper atmosphere, we could cool the planet. and if we continued to spray, we could continuously cool the planet and offset greenhouse warming. >> the problem is sulphur dioxide damages the ozone, making the process hard to undo if things go awry. >> they would have to step up over time as cin dioxide went up over time. you'd have to step up the sprging to counterracket it. scientists have been looking at the way the ocean takes co2 out

of the atmosphere. they looked at phyto plankton, the results visible from space. there are concerns this could have negative impacts on the ocean. other technology and development include large machines that can remove carbon dioxide from the air. >> the technologies are all currently quite hypothetical. they'll take a long time to develop and be relatively expensive. as seductive as it is. most offer a short-term, local solution, they are extensive. unprove and could make things worse. >> new technologies have a role to play. most scientists say they won't

about a substitute for reducing carbon emissions. >> that's it for the international newshour. in the next hour, the controversial no child left behind act overhaul, and what it means for the child in the class room. back with more news in two minutes.

good evening. this is al jazeera america. planning attacks years before last week's shooting in california, what the f.b.i. is revealing about the san bernardino couple who massacred 14 people. rallying for change, the police tactics that have demonstrators calling for chicago's mayor to resign. responding to his critics, donald trump justifies his comments about banning muslims from entering the u.s. and the threat he is making