July 9 (Bloomberg) -- Bob Brown, leader of the Australian Greens party that now holds the balance of power in the Senate, will push for the government to cut greenhouse gases by 90 percent by 2050.

The five Greens Senators will push for deeper emissions cuts and a tougher carob trading system, Brown said. The government has vowed to cut gases by 60 percent by 2050 and has not yet set short-term targets.

``The importance is urgency,'' Brown told the National Press Club in Canberra. ``We want a 40 percent cut in emissions by 2020 and approaching carbon neutral by 2050, with a 90 percent cut in gases.''

Ross Garnaut, the government's adviser on global warming, said on July 5 Australia should introduce a ``broadly based'' emission trading system that should start with a two-year ``transition period'' from 2010. Prime Minister Kevin Rudd is currently meeting with Group of Eight leaders in Hokkaido, Japan on global warming, food and energy security.

Garnaut's system will use the so-called cap-and-trade design used in the European Union. Companies are set an emissions cap and must hold sufficient permits to meet that limit. If they exceed the target, they buy permits from businesses that have undershot their respective caps.

The government has 32 seats in the 76-member Australian Senate. It needs support from the five Greens as well as Family First Senator Steve Fielding and newly elected Independent anti- gambling campaigner Nick Xenophon to pass laws. The new Senate came into effect on July 1 and it first meets in Canberra on Aug. 26.

-- Editors: John McCluskey

To contact the reporters on this story: Gemma Daley in Canberra at gdaley@bloomberg.net

Last Updated: July 9, 2008 01:37 EDT