Small island nations demand more emissions cuts

* Small island states demand more ambitious steps

* Destruction from rising sea levels feared

By Anupreeta Das

UNITED NATIONS, July 10 (Reuters) - This week's pledges by G8 leaders to cap increases in the world's temperature are insufficient, a group of small island countries that face potential catastrophe from climate change said on Friday.

The Alliance of Small Island States, a United Nations-based group of 42 island nations, called on the world's richest countries and major economies to take more concrete and ambitious steps to fight global warming.

The G8 countries and another 17-country group, the Major Economies Forum, agreed in L'Aquila, Italy, that global average temperatures should not be allowed to rise more than 2 degrees Celsius (3.6 Fahrenheit) by 2050.

"Two degrees of temperature rise is unacceptable," AOSIS Chair Dessima Williams told reporters at the United Nations.

If global temperatures increased that much, many island countries -- already vulnerable to hurricanes, cyclones and other adverse weather -- could get wiped off the map by rising sea levels, Williams said.

"The world has an obligation to ensure that no island is left behind," said Williams, who is also Grenada's ambassador to the United Nations. The group counts Barbados, Seychelles and Trinidad and Tobago among its members.