People are making lifestyle changes as concern over global warming grows.

Nearly four in five people (77.7 per cent) polled in a Herald-Digipoll survey believed they needed to make lifestyle changes to reduce global warming.

Two-thirds of the 1003 people surveyed had installed energy-efficient lightbulbs in their home while more than half (56.3 per cent) had cut down on car use. Two in five people (39.1 per cent) had switched to a more fuel-efficient car.

Andrew Mackenzie, managing director of Albany Toyota, said car sales trends had been driven by high petrol prices and concerns over climate change.

"There is definitely a trend towards people giving consideration to the cost of running a vehicle. They're also thinking about what the vehicle has done to the environment in the past and what they can do to help the environment in the future."

The firm has seen "at least a 10 per cent increase in sales" of its small cars in the past six months.

Sales of its hybrid vehicle, the Prius - new and used - have also increased steadily.

But George Seymour, managing director of Honda New Zealand, believed car sales trends have been influenced more by fuel prices than "a feeling about global warming, unfortunately".

He said consumers were beginning to revert to bigger cars as fuel prices drift off a historic high.

"Unfortunately, fuel prices have come down. I would have liked to see them stay up."

If fuel prices remained stagnant, the shift to small cars would slow, he said.

For every car it sells, Honda NZ funds the planting of 10 native trees.

"We're doing as much as we can to promote the global warming story and social responsibility."

Mr Seymour believed Government action was needed.

"They need to get on, quite frankly. They've been studying and studying and studying, and they need to make decisions."

Nevertheless, National Institute of Water and Atmospheric Research principal scientist David Wratt said the poll results were heartening.

"It shows that people are thinking about the issue seriously," said Dr Wratt.