''We really need to start moving quickly,'' he said yesterday.
A new report by the Intergovernmental Panel on Climate Change (IPCC) shows global emissions of greenhouse gases had risen to unheard-of levels, despite a growing number of policies to reduce climate change.
Emissions grew more quickly between 2000 and 2010 than in each of the three previous decades, the report said.
''There is a clear message from science: To avoid dangerous interference with the climate system, we need to move away from business as usual,'' report co-chair Ottmar Edenhofer, of Germany, said.
Prof Lloyd said the urgency of attending to climate change mitigation could not be overstated because unless the rapidly increasing current world CO2 emissions curve was turned, the IPCC report suggested the world was on the way to a climate regime with temperature increases from between 3.7degC and 4.8degC.
''There is no way that mitigation can be effective unless we get buy-in by all countries of the world. The atmosphere does not care if the emissions come from New Zealand or India or any other specific nation.''
New Zealand was known as a reasonably aggressive negotiator as it tried to do the right thing for the country, he said.
Government negotiators had been trying to advance the economy by avoiding the short-term financial costs of agreeing to substantial reductions.
''But that self-interested point of view is not getting us anywhere. The only way to solve the problem is for all countries to take their fair share of emissions cuts.''
New Zealand was better placed than nearly all countries in the world, with a particularly high proportion of its electricity supply already coming from renewable sources including hydro, geothermal and wind, he said.
''There is no excuse. To get global buy-in New Zealand must act as a global leader in emissions reductions not a selfish backwater.''
The big problem was storage of renewables but combined with hydro, which had its own storage, New Zealand had considerable advantages, he said.
The report's estimation of the global cost as less than 1% of the world's gross domestic product (GDP) was rather ''optimistic'' as his own research had shown it would be more likely to cost up to 10% of GDP, Prof Lloyd said.
However people needed to look past the short-term costs to the longer-term gains.
''In the longer term, we'll be better off. There won't be the droughts or the dispossessed people.''
He believed the consequences of climate change would swamp any economic gains made in the short term.
Minister for Climate Change Issues Tim Groser said the report's findings told him New Zealand was on the right track in pressing for a binding international agreement on emissions beyond 2020 that was genuinely global in its scope and flexible, catering for countries' individual circumstances and allowing them to play to their strengths.
''New Zealand is doing its fair share on climate change, taking into account our unique national circumstances, both to restrict our own emissions and support the global efforts needed to make the cuts that will limit warming.''
New Zealand had made an unconditional promise to take responsibility for its own emissions, with a target of 5% below 1990 levels by 2020.
