Forecast for the future

Measuring climate change may not be an exact science, but climate change happens, and the challenge is to adapt with it, says South Pacific Applied Geoscience Commission (Sopac) director Cristelle Pratt.

Suva-based Sopac is working with other regional groups in the Pacific, helping to prepare countries for the effects of climate change.

Pratt says that includes the need for long-term monitoring to better determine what is natural process and what is human-induced, and improve the forecasting of events such as storms, floods and droughts.

"The priority is to understand what the risks are and what we can do in getting that information to the communities so they can respond effectively."

That will include looking at geology, climate hazards and how warning systems can be developed.

Sopac will also investigate areas such as the stability of coastlines and where protective structures might work, although expensive seawalls often cause more problems than they solve.

Pratt says there must be commitment about what it means for countries to be good global citizens and take responsibility.

A 2003 report published by Sopac says small Pacific nations are particularly vulnerable to climate change because of their remoteness and size. The more than 30,000 small islands in the Pacific vary in physical characteristics.

Polynesian and Micronesian islands comprise small island groups consisting of a mixture of large volcanic islands and small coral atoll islands (American Samoa, Cook Islands, Federated States of Micronesia, Fiji, French Polynesia, Guam, Palau, Samoa and Tonga) or only atolls (Kiribati, Marshall Islands and Tuvalu) or small uplifted limestone islands (Nauru and Niue). Those most vulnerable to cyclones lie north and south of the five-to-10 degree latitude band each side of the equator, including Samoa, the Cook Islands and Niue.

Scientists argue that with global warming, the intensity of cyclones is increasing as they partly derive their power from warm water, a sea surface temperature of 27C or more.

The frequency of cyclones has already been related to El Nino episodes when there is extensive warming of the upper ocean in the eastern Pacific.

Now they are forecast to become more severe and more destructive with raised sea levels because of the expansion of water as it warms. The International Panel on Climate Change has estimated at present rates the mean sea level could rise by up to one metre by 2100.

Some scientists predict a global warming threshold of 2C above the prevailing world temperatures in 1750 (before the industrial revolution) could be reached in the next 10 years, resulting in agricultural failure, major droughts, increased disease and sea level rises.

Since 1750 global averages have already risen by 0.8C. Globally, sea water has warmed about half a degree in 50 years, but not all scientists are convinced of the links to cyclones or hurricanes. Last month, the journal Science reported Georgia Institute of Technology research claiming category 4 and 5 cyclones had doubled in number since the 1970s, but the research was later criticised for using allegedly unreliable data.

The Sopac report says although climate change scenarios for Pacific Island countries vary, most models predict an increase in frequency of El Nino episodes and increased intensity of cyclones.

In the South Pacific, the cyclone season runs from November to April and can cause huge storm damage and flooding with, at times, loss of life, demolished infrastructure, damage to agriculture, long-term social damage and contamination of freshwater lenses (the layer of freshwater that lies beneath atolls).

Pacific nations are also threatened by volcanic eruptions, landslides, earthquakes and tsunami. Other less dramatic problems include coastal erosion, often exacerbated by beach mining, flooding, droughts, pollution of groundwater resources, ocean acidification and coral bleaching.

At a Pacific regional disaster management meeting in Papua New Guinea this year it was noted that disaster risk management and planning were impeded by resource constraints and a serious lack of capacity in many nations.

The Pacific Regional Environment Programme, based in Samoa, has identified areas to work on climate change challenges, including strengthening the meteorological service, understanding climate variability and developing an overall policy.