Tag Archives: CSIRO

Students perform at the Abaunamou Pri-School Climate Change Skit Competition. Photo: KAPIII

Future climate

Climate impacts almost all aspects of life in Kiribati. Understanding the possible future climate of Kiribati is important so people and the government can plan for changes.

Read more: How do scientists develop climate projections?

Temperature will continue to increase

Projections for all emissions scenarios indicated that the annual average air temperature and sea surface temperature will increase in the future in Kiribati. By 2030, under a high emissions scenario, this increase in temperature is projected to be in the range of 0.3 – 1.3 degrees Celsius for the Gilbert and 0.4 – 1.2 for the Phoenix and Line Islands.

Table 1: Projected annual average air temperature changes for Kiribati for three emissions scenarios and three time periods. Values represent 90% of the range of the models and changes are relative to the average of the period 1980 - 1999. Source: www.pacificclimatechangescience.org

Table 1: Projected annual average air temperature changes for Kiribati for three emissions scenarios and three time periods. Values represent 90% of the range of the models and changes are relative to the average of the period 1980 – 1999. Source: www.pacificclimatechangescience.org

More very hot days

Increases in average temperatures will also result in a rise in the number of hots days and warm nights and a decline in cooler weather.

Changing rainfall patterns

Almost all of the global climate models project an increase in the average annual and seasonal rainfall over the course of the 21st century. however, there is some uncertainty in the rainfall projections and not all models show consistent results. Droughts are projected to become less frequent throughout this century.

More extreme rainfall days

Model projects show extreme rainfall days are likely to occur more often.

Sea level will continue to rise 

Sea level is expected to continue to rise in Kiribati. By 2030, under a high emission scenario, this rise is projected to be in the range of 5 – 14 cm. The sea-level rise combined with natural year-to-year changes will increase the impact of storm surges and coastal flooding. There is still much to learn, particularly how large ice sheets such as Antarctica and Greenland contribute to sea-level rise, scientists warn larger rises than currently predicted could be possible.

Table 1: Sea-level rise projections for Kiribati for three emissions scenarios and three time periods. Values represent 90% of the range of the models and changes are relative to the average of the period 1980-1999. Source: www.pacificclimatechangescience.org

Table 1: Sea-level rise projections for Kiribati for three emissions scenarios and three time periods. Values represent 90% of the range of the models and changes are relative to the average of the period 1980-1999. Source: www.pacificclimatechangescience.org

Ocean acidification will continue

Under all three emissions scenarios (low, medium and high) the acidity level of sea waters in the Kiribati region will continue to increase over the 21st century, with the greatest change under the high emissions scenario. The impact of increased acidification on the health of reef ecosystems is likely to be compounded by other stressors including coral bleaching, storm damage and fishing pressure.

Read also:

Information on this page has been sourced on behalf of the Kiribati Meteorology Service and with kind permission from Australian Bureau of Meteorology and CSIRO, 2011.Current and future climate of Kiribati. Visit www.pacificclimatechangescience.org to download information brochures. For further information on this topic please refer to Volume 2 of Climate Change in the Pacific: Scientific Assessment and New Research

The new village is now under threat of inundation and sea walls have to be constantly maintained. Photo: Justin McManus, The Age

Changing climate

Temperatures have increased

Annual and seasonal maximum temperatures have increased in Tarawa since 1950. Maximum temperatures have increased at a rate of 0.18 degrees Celsius per decade. These temperature increases are consistent with the global pattern of warming.

Figure 3: Annual average temperature for Tarawa. Light blue bars indicate El Nino years, dark blue bars indicate La Nina years and the grey bars indicate neutral years. Source: www.pacificclimatechangescience.org
Figure 3: Annual average temperature for Tarawa. Light blue bars indicate El Nino years, dark blue bars indicate La Nina years and the grey bars indicate neutral years.

Annual rainfall has increased

Data since 1951 for Kirimati show a clear increasing trend in annual and wet season rainfall, but no trend in annual and wet season rainfall, but no trend in the dry season. At Tarawa, rainfall data show no clear trends. Over this period, there has been substantial variation in rainfall from year to year at both sites.

Figure 4: Annual rainfall for Kiritimati. Light blue bars indicate El Nino years, dark blue bars indicate La Nina years and the grey bars indicate the neutral years. Source: www.pacificclimatechangescience.org

Figure 4: Annual rainfall for Kiritimati. Light blue bars indicate El Nino years, dark blue bars indicate La Nina years and the grey bars indicate the neutral years. Source: www.pacificclimatechangescience.orgSea level has risen

Sea level has risen

As ocean water warms it expands causing the sea level to rise, the melting of glaciers and ice sheets also contributes to sea-level rise.

Instruments mounted on satellites and tide gauges are used to measure sea level. Satellite data indicate the sea level has risen across Kiribati by 1 – 4mm per year since 1993, compared to the global average of 2.8 – 3.6 mm per year. Sea level rise naturally fluctuates from year to year and decade to decade as a result of phenomena such as the El Nino-Southern Oscillation.

Figure 6: Observed and projected relative sea-level change in Kiribati. The observed sea-level records are indicated in dark blue (relative tide-gauge observations) and light blue (satellite record since 1993). Reconstructed estimates of sea level near Kiribati (since 1950) are shown in purple. The projections for the A1B (medium) emissions scenario (representing 90% of the range of models) are shown by the shaded green region from 1990 to 2100. The dashed lines are an estimate of the 90% of the range of natural year-to-year variability in sea level.

Figure 6: Observed and projected relative sea-level change in Kiribati. The observed sea-level records are indicated in dark blue (relative tide-gauge observations) and light blue (satellite record since 1993). Reconstructed estimates of sea level near Kiribati (since 1950) are shown in purple. The projections for the A1B (medium) emissions scenario (representing 90% of the range of models) are shown by the shaded green region from 1990 to 2100. The dashed lines are an estimate of the 90% of the range of natural year-to-year variability in sea level.

Ocean acidification has been increasing

About one quarter of the carbon dioxide emitted from human activities each year is absorbed by the oceans. As the extra carbon dioxide reacts with sea water it causes the ocean to become slightly more acidic. This impacts the growth of corals and organisms that construct their skeletons from carbonate minerals. These species are critical to the balance of tropical reef ecosystems. Data show that since the 18th century the level of ocean acidification has been slowly increasing in Kiribati’s waters.

Read also:

Information on this page has been sourced on behalf of the Kiribati Meteorology Service and with kind permission from Australian Bureau of Meteorology and CSIRO, 2011.Current and future climate of Kiribati. Visit www.pacificclimatechangescience.org to download information brochures.