The group of 20, including five senior counsel such as former Liberty Victoria president Brian Walters, have signed the letter.

It states that the rights of many — including Pacific Islanders whose homes are under threat from the effects of climate change — must be considered in making setting an emissions reduction target.

In contrast, Australia is expected to press ahead using a scheme with targets to reduce emissions by between 5pc and 25pc.

The actual figure will depend on whether the world achieves a new, comprehensive post-Kyoto agreement.

Australia is expected announce its emissions targets in the much-awaited white paper to be released on Monday.