More than 120 leaders attended the Climate Summit, however, Australian Prime Minster Tony Abbott was conspicuously absent. Credit:AFP Prime Minister Tony Abbott was on his way to New York at the time for the UN Security Council meeting on global terrorism, but the man who built his 2013 election win on a promise to roll back a price on carbon, had pointedly refused to attend the climate meeting. Instead he sent Foreign Minister Julie Bishop to present the case for his as yet unlegislated Direct Action replacement scheme. The US President argued that the problem of climate change had surpassed terrorism as the biggest threat to life on Earth. "For all the immediate challenges that we gather to address this week – terrorism, instability, inequality, disease – there's one issue that will define the contours of this century more dramatically than any other, and that is the urgent and growing threat of a changing climate," Mr Obama said.

US President Barack Obama said climate change would be the defining issue of the century. Credit:AFP "In America, the past decade has been our hottest on record. Along our eastern coast, the city of Miami now floods at high tide. In our west, wildfire season now stretches most of the year. In our heartland, farms have been parched by the worst drought in generations, and drenched by the wettest spring in our history. A hurricane left parts of [New York City] dark and underwater. And some nations already live with far worse. "Worldwide, this summer was the hottest ever recorded – with global carbon emissions still on the rise. Actor Leonardo Di Caprio told the summit that "the time to answer humankind's greatest challenge is now." Credit:AFP This past Sunday, nearly 400,000 people marched in New York to show support for action on climate change, and similar events were held on the same day in more than 160 countries worldwide. President Obama noted that as "our citizens keep marching ... we cannot pretend we do not hear them".

"We have to answer the call ... we cannot condemn our children, and their children, to a future that is beyond their capacity to repair." Actor Leonardo DiCaprio also weighed in, dubbing global warming the greatest challenge humans face. "Now it is your turn," he told the high-powered session. "The time to answer humankind's greatest challenge is now. We beg of you to face it with courage and honesty." But the language of the Australian Foreign Minister was far less emotional.

"Australia remains committed to reducing its emissions by five per cent below 2000 levels by 2020," Ms Bishop told the summit. "This is a bipartisan target. It is an ambitious target because it means that Australia will reduce its emissions by 22 per cent against business as usual levels. This compares well to the targets of other major economies." She said Australia was still moving to take "serious domestic action" on global warming. "We have committed significant funds – $2.55 billion – to an Emissions Reduction Fund. The Fund is the UN Secretary General Ban Ki-moon staged the summit in the hope of kick-starting climate negotiations ahead of a Paris meeting on global warming set for 2015.

The Abbott government has removed the carbon price introduced by the former Labor government and is looking to trim down the renewable energy target amid complaints from fossil fuel energy generators that retail power consumption has dropped as people switch to clean energy and look to consume less electricity overall. 'Short-term thinking' Australia's statement at the UN Climate Summit was labelled disappointing by environment groups on Wednesday in comparison to announcements by other countries. The Climate Institute said while the summit had brought a "mixed bag" of commitments from world leaders, the Abbott government's failure to share a post-2020 target put Australia at risk of being bogged in the backwaters as other countries and capital move on in serious climate action, investment and opportunities". "Unlike others, Australia's only commitment to share a post 2020 target was after it reviewed that of all its 'trading partners and competitors' – without a specific timeline. This appears to completely ignore its previous commitment to play its fair part in global action to avoid dangerous climate change," CEO John Connor said from New York.

"Australia's national interest should not be defined solely by the perceived impact of action on our pollution intensive industries." Environment Minister Greg Hunt told Fairfax Media on Tuesday the government was committed to its review of Australia's targets next year and would complete the process in time to meet its international deadlines. The UN has demanded countries establish targets beyond 2020 by the end of March next year. Economist Frank Jotzo from ANU's Crawford School of Public Policy said the statements from the United States and China showed those countries were taking positive steps to do more to combat climate change. While the US has not yet set its targets for the next three decades, its submission to the United Nations Framework Convention on Climate Change foreshadows emissions cuts of 30 per cent by 2025, 42 per cent by 2030 and 83 per cent by 2050.

China made clear its intentions to enact a national emissions trading scheme, put a cap on total energy consumption and vigorously develop non-fossil fuels. Dr Jotzo said Australia, by contrast, was stuck in what was now considered "old thinking", in which economic growth was seen as a trade-off for action on global warming. "That's not the paradigm being used by China or even the US," Dr Jotzo said from New York. "They see climate change as an opportunity for economic growth He said Australia's position was rooted in the view that "coal is king", an outlook that ignored the fact that Australia would not determine how much coal the rest of the world would use.

"When you look a little further ahead, really the strategy for Australia should be to search out opportunities in a low carbon world," he said. Loading "Australia is an energy superpower and can be an energy superpower no matter what type of energy the world chooses." Follow us on Twitter