The University of Otago emeritus botany professor is also chairman of the political lobby group Wise Response, which submitted a petition in April last year asking the Government to conduct a risk assessment on a wide range of issues, including climate change.
Last month, a parliamentary committee responded to the petition, saying the Government was already doing enough to address the issues outlined.
That response prompted Sir Alan and a group of other environmentalists to write an open letter calling on Prime Minister John Key to change New Zealand's ''grossly inadequate'' emissions reduction target.
The letter writers urged Mr Key to ''make a commitment to zero fossil fuel emissions by 2050''.
''The consensus in the scientific community is that global warming should remain under an average of two degrees above pre-industrial levels if we are to avoid catastrophic climate change,'' the letter reads.
''For this target to remain achievable, the use of fossil fuels must be eliminated by the year 2050. New Zealand must commit to at least this level of action.''
Sir Alan said yesterday New Zealand had a responsibility to bring climate change action to the fore on behalf of the smaller Pacific nations that were already being hit by sea level rise as a result of climate change.
''New Zealand should face up to that responsibility, and use its role in the [United Nations] Security Council ... to impress on the world the importance of addressing climate change in terms of the future prospects of human generations to come,'' he said.
''And not leave them to flounder in an environment which will be almost impossible to deal with.''
