Indicators for Climate Change over Mauritius Mr. P Booneeady Pr. SDDV Rughooputh

Research Objectives Determine whether the climate in Mauritius is changing and how it may be affecting our lives, the natural environment and our economy. Alert on the impact of climate change as it develops and instils a sense of urgency in responding to it. Establish a baseline against which future perturbations due to climate change or variability could be measured. Develop indicators for climate change over Mauritius

Background Almost all the aspect of nature and human life depends on the climate and in turn the climate influences the fauna and flora. When the climate patterns changes, all of these are affected, some slightly and others very strongly. Climate change is about shifts in the meteorological conditions lasting many years which include whether it is becoming warmer, drier or sunnier. Climate change may have large impacts on our economy and daily lives.

Indicators Selected from different fields, namely: meteorology, marine, environment, health and behaviour of plants. Are those with a long-term and accurate historic datasets that show close correlation in time. Indicators which have been selected includes air temperature, rainfall, drought index, sea level rise, tropical cyclone, thunderstorm and health Statistical techniques have been used to test the relevance and significance of these indicators

Temperature An increase of about 0.8 o C on the mean temperature has been noted from 1975 up to Decadal trends indicate a shift towards the south and the centre The number of hot days have increased. The number of cold days have decreased

Rainfall the annual rainfall is found to be decreasing at about 1.3 mm per year. »1.0 mm per year for summer » 0.7 mm per year for winter A shift in the start of rain indicates that the summer rain is being delayed more in the coastal regions than at the centre of island. Longer period of dry spells in the coming years.

Sea level Rise Sea level in Mauritius indicate that the sea level is now increasing quadratically Seasonal variation in the sea level whereby it is, on average, 0.2m higher in summer than in winter. For the period 1988 to 2008, the rate of increase is 4.0mm per year, slightly above the satellite observed value.

Tropical Cyclones A decadal increase in the occurrence of intense to very intense tropical cyclones indicates that most of the storms forming over the southern Indian Ocean will intensify at least to the tropical cyclones intensity

Thunderstorms A temporal increase in thundery activity over Mauritius A negative correlation of the number of thunderstorms with the sunspot Negative influence of ENSO on the formation of cumulonimbus clouds

Health A positive correlation between the temperature and the number of food poisoning. A positive correlation between the temperature and the number of cataract cases. Other forms of vector and air borne diseases: –Gastro-enteritis peaks in September to October –Conjunctivitis peaks in August to October –Respiratory diseases peak in June and July

Challenges Optimize variograms particularly for summer months to improve accuracy of models Derive values of humidity, wind speed and direction, pressure and temperature on a regular grid from few available stations.

Limitations Access to data Data available for a short period of time except for the meteorological data

Future Works (1) Study the interconnections between the different indicators. Develop other relevant indicators for Mauritius. Use advanced spatial geostatistics techniques in order to come-up with various GIS layers to map out features (for example, floods and vector/airborne diseases) which will give a deep insight about the future dangers or risks. This will thus enable us to prepare our country to face the coming undesirable events by developing timely mitigation plans.

Future Works (2) Carry out a national survey in order to investigate the perceptions and notion of Mauritians concerning climate change and its consequences. Consider global indicators such as Southern Oscillation Index and Indian Ocean Dipole. Extend the study to include the outer islands of Mauritius: Rodrigues, St Brandon and Agalega to cover the SWIO Develop a website to reflect climate change indicators for Mauritius and the outer islands

Conclusions Give a greater understanding that the climate change trends and its impacts over Mauritius. Help to adapt to climate change as the mitigation measures reduce the scale of future impacts. Able to reduce some of the adverse impacts of climate change through mitigation and adaptation and enhance some of its potential benefits

Acknowledgements University of Mauritius for providing logistic support. Mauritius Research Council for funding this study. Mauritius Meteorological Services for providing required data.