Academics are criticising Finance Minister Bill English for describing a report on rising sea levels as "speculative".
Mr English was reacting to environment watchdog Jan Wright's report, released last week, which urged the Government to take a stronger role in planning for rising sea levels.
Parliament's commissioner for the environment said homes, businesses and infrastructure built on low-lying coastal land would be at risk over time.
Dr Wright suggested the Government should think about starting to put money aside to cover compensation claims that could run into billions.
Mr English said the report was "pretty speculative" and he wasn't planning on putting any money aside.
He said the Government had other risks to consider, and home owners had incentives to ensure their properties were safe.
The Tertiary Education Union, which represents university and polytech staff, says the report was based on the work of highly-regarded scientists and academics from around New Zealand and around the world.
"By dismissing those scientists and their work Bill English is not only ignoring strong evidence, he is risking our future," TEU national president Sandra Grey said today.
"Politicians can't pick and choose what evidence they want to hear.
"An overwhelming majority of climate scientists and academics say there is a real, measurable and urgent issue that we need to address - it is not speculative."
Dr Grey is urging academics to join the climate marches this weekend to show their support for scientists who continue to raise important issues "despite the disparaging and denigrating attitude they face from politicians".