Al Gore (R) and US President Bill Clinton (L)

Former US vice president Al Gore Wednesday hailed recent moves by the United States and other nations to confront climate change as "extraordinary", and encouraged Australia to join global efforts.
The high-profile environmental activist described as "significant" a plan by Australian mining magnate and politician Clive Palmer to push for the introduction of an emissions trading scheme in return for helping dismantle the country's contentious carbon tax.
Gore, who is in Australia as part of an environmental training programme, praised the "extraordinary moment in which Australia, the United States and the rest of the world is finally beginning to confront the climate crisis in a meaningful way".
He said he believed that pricing carbon was "ultimately to be critical to solving the climate crisis".
"I am extremely hopeful that Australia continues to play a global leadership role on this most pressing issue," Gore added.
Palmer -- famous for his plans to build a full-scale replica of the Titanic -- leads of one of several smaller political parties with which the government must work to pass legislation to scrap the carbon tax.
The conservative administration, led by Prime Minister Tony Abbott, made abolishing the tax one of its key election promises.
Palmer said his Palmer United Party would support the tax's removal if it was replaced by an emissions trading scheme with a starting carbon price of zero.
He said his scheme would only begin once Australia's major economic partners established similar programmes.
"Australia acting alone cannot change the world, and change the world we must, not just for ourselves but for our children, not just for them but for all the children in the world, not just for our time but for all time," Palmer said at a joint press conference with Gore.
"Climate change is a global problem and it must have a global solution."
Environment Minister Greg Hunt said later an emissions trading scheme was "not our policy" but his government had not yet seen Palmer's suggested amendments to the legislation.
The government proposes to replace the tax with a plan which includes incentives for companies to increase energy efficiency.