riek machar is not really representative of the opposition in sudan. and the sooner we stop talking about rebelsas loyal to riek machar and start saying that there is an ethnic dimension to this but there is also a political dimension. and that political dimension insofar as there's powerful opposition to salva kiir, is not in reaction to riek machar. >> a lot of this violence has been in oil rich areas, and oil production has crashed which means an oil poor country is getting poorer. >> it's not source of the conflict. it broke out over political issues and deep problems in governing the country. once it broke out control of the oil area becomes a strategic objective for each side. for south sudan 98% of the budget comes from oil. so for those opposed to salva kiir, taking over the source of oil also destroys his source of income. so it has now become a matter of concern but not at the root of the problem. >> eric, what has to be done? there are -- the u.n. is there on the ground. there are all sorts of human rights groups there. but again, doctors wi

the president's troops are battling rebels loyal to riek machar. a ceasefire signed in jan ended. peace talks in ethiopia are making lit the progress. >> violence broke out in john barasso, during a process against government austerity measures. activists threw rocks and fire crackers. the police responded with batons, around a quarter of the workforce is unemployed and the country is continuing to battle an economic crisis. >> millions of people in 150 countries are taking part in the earth hour campaign. city after city has tape turns to shut off lights to show their commitment to the planet. we have this report. >> it was sydney that started the earth hour movement eight years ago - a bright idea for a city to go dark, to raise awareness about the environment. today the campaign is planet wide. 7,000 cities taking turns to switch off their lights at 8:30pm local time. hong kong's harbour distinguishable. paris, the city of light without its usual glow from the eiffel tower. landmarks in moscow, tehran and dubai - sitting in the blackness of night. >> it's a voice to stand up an