AAP: GREENS leader Bob Brown has warned the government not to lose its nerve on an emissions trading scheme as Treasurer Wayne Swan refused to commit to its 2010 timetable. Just a week ago Climate Change Minister Penny Wong indicated there was no reason to delay the start of an ETS because of the current international turmoil. But today Treasurer Wayne Swan was giving no such guarantees. Mr Swan told ABC TV the government was planning to review all spending commitments amid …