By Alex Kirby
BBC News website environment correspondent
A leading UN official says the world must guard against natural catastrophes such as the Indian ocean tsunami, and the threat of climate change as well.
Shipping can create waste problems for island states
Dr Klaus Toepfer, director of the UN Environment Programme, said the tsunami and changing climate were not linked.
But he said it would be a huge mistake to concentrate on just one threat while giving less attention to the second.
Dr Toepfer said poor people affected by the tsunami were suffering twice over, as they could not pay for insurance.
He said some of the governments in the region had asked Unep and other UN agencies to start work on a feasibility study for a tsunami warning system.
Some experts say the world's preoccupation with the prospect of climate change has distracted attention from more immediate threats like the 26 December calamity.
Dr Toepfer told the BBC News website: "I'm convinced it would be a massive mistake to try to calculate one threat against the other.
"We can only praise the solidarity of people worldwide and join in their sorrow those who have lost loved ones. We want to do our utmost.
The world's voracious appetite for fish threatens some islands
"We must underline that, totally independent of this disaster, there's an increase in extreme weather and sea levels.
"We have to be aware of the actions of Nature which we can't predict. Taking precautions against them is now on the highest agenda. But we have not and we will not play off one threat against the other."
Dr Toepfer was speaking at the launch of a Unep report on the plight of small island developing states, known as Sids.
Unep says the problems Sids face worldwide include freshwater shortage, pollution, loss of species, and climate change.
Its report is published four days before a UN-organised conference on sustainable development in Sids.
An average Caribbean cruise ship produces an estimated 50 tonnes of solid waste a week
Mauritius uses three times as much fertiliser per hectare as western Europe
Fish catches in Vanuatu fell by more than two-thirds between 1999 and 2001
The conference, from 10 to 15 January, is the Mauritius International Meeting, a 10-year review of the states' problems and progress towards sustainable growth.
Unep says: "Sids across the world are facing uncertain economic and environmental times as a result of shifts in demands for commodity crops such as sugar and bananas, sometimes rising populations with a thirst for modern, consumer living and emerging, wide-ranging threats, such as climate change.
"Most remain hampered by their remoteness, small GNPs with little chance of economies of scale for tackling issues such as domestic and industrial wastes, and by the difficulties of getting access to the technologies they need."
For Sids in the Atlantic and Indian oceans, Unep says, freshwater and climate change are among the top concerns.
Pollution from agriculture and wastes exacerbates water supply problems, which make it easier for disease to spread.
Water shortage harms the banana crop in the Caribbean
In the Caribbean, a region with some of the world's most intensive maritime traffic, pollution from cruise ships and other vessels is among growing threats to health and national economies, Unep says.
Household and industrial wastes and reductions in freshwater availability are again concerns, sometimes intensified by tourism in the form of luxury hotels and golf courses. There are also worries over climate change and invasive alien species.
Climate change ranks high among the concerns of Pacific Sids, Unep says, together with the over-exploitation of coastal fish stocks and rapid population growth.