The Changing Climate of Mauritius. By SureshYadowsun Boodhoo, Director, Meteorological services

Transcription

1 The Changing Climate of Mauritius By SureshYadowsun Boodhoo, Director, Meteorological services

2 Introduction Human-induced climate change is probably becoming the most debated topics as the impacts gradually become known and are revealed to have negative, and often difficult to predict, consequences on all natural ecosystems, on socio-economic factors, health and food security. The impacts are even stronger for small islands states with limited resources.

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4 CLIMATE CHANGE TOPICS Causes Effects Direct Impacts Climate Change and Sustainable Development Response Measures

5 Climate System Earth s climate is determined by complex interactions between the Sun one hand and, the oceans, atmosphere, cryosphere, land surface and biosphere (part of the Earth s surface or atmosphere inhabited by living things) on the other. The Sun is the principal driving force for weather and climate. The uneven heating of the Earth s surface causes convective flows in both the atmosphere and oceans, and is thus a major cause of winds and oceans currents.

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7 Rising concentrations of anthropogenic greenhouse gases in the Earth s atmosphere are leading to changes in the climate and the climate system

8 Primary Contributors to the Natural Greenhouse Effect Carbon Dioxide Other ~25% ~10% ~65% Water Vapour

9 The IPCC-Analysis & Predictions Global : Current atmospheric concentrations of carbon dioxide, the most important of the GHGs, and methane far exceed pre-industrial values determined from ice cores spanning the last 650,000 years. Year 1750 = 280 ppm (Industrial Revolution starts) Present = 381ppm Causes: fossil fuel (Industries, cars etc),agriculture, and land-use changes (deforestation, recreation..)

10 CLIMATE CHANGE IMPACTS ON Cyclones Storm Surge Floods Drought Warm Climate Bugs Beach Erosion Food security Human Well-Being

11 IPCC Global temperature trend

12 Local Temperature trend MAXIMUM TEMPERATURE ANOMALIES - VACOAS M a x i mum 10 pe r. M ov. Av g. ( M a x i mum) 1951

13 Local Temperature trend MAXIMUM TEMPERATURE ANOMALIES - PLAISANCE 1951 to 2006 Maximum 10 per. Mov. Avg. (Maximum)

14 Local Temperature trend Rodrigues rods 5 per. Mov. Avg. (rods) 10 per. Mov. Avg. (rods) St Brandon Agalega Maximum 1.5 Maximum per. Mov. Avg. (Maximum) 1 10 per. Mov. Avg. (Maximum)

15 Direct Impacts Energy consumption (GHG Emission) Economics Human Well-being Pressure on water sector

16 IPCC- Global Water Analysis & Predictions The frequency of heavy precipitation events has increased, consistent with warming and observed increases of atmospheric water vapour More intense and longer droughts have been observed over wider areas since the 1970s, particularly in the tropics and subtropics. Increased drying due to higher temperatures and decreased precipitation have contributed to these changes.

17 IPCC- Fresh water resources and their management By mid-century, annual average river runoff and water availability are projected to decrease by 10-30% over some dry regions at mid-latitudes and in the dry tropics Drought-affected areas will likely increase in extent. Heavy precipitation events, which are very likely to increase in frequency, will augment flood risk. Water supplies stored in glaciers and snow cover are projected to decline.

18 Local Precipitation Trend Trend in Annual Rainfall-Vacoas Annual Rainfall 10 per. Mov. Avg. (Annual Rainfall) Millimetres Year

19 Local Precipitation Trend Trend in Annual Rainfall Over Mauritius ANNUAL RAINFALL 10 per. Mov. Avg. (ANNUAL RAINFALL) MILLIMETRE YEAR

20 Direct Impacts Demands growing too fast 10 l in 1960 to 250l at present Increase storage economics Agriculture at stake Damage to ecosystem (as a result of sea water intrusion up to 3km inland) Human well-being

21 Hotter Summer? MEAN TEMPERATURE AT VACOAS - DEC,JAN, FEB YEAR TEMPERATURE (ºC)

22 Hotter Summer? MEAN TEMPERATURE AT PLAISANCE - DEC,JAN,FEB Y EA R

23 Hotter Summer? MEAN TEMPERATURE FOR MEDINE - DEC,JAN,FEB YEAR TEMPERATURE (ºC)

24 Direct Impacts Energy demand for space cooling environment and economics Pressure on water sector Human well-being

25 Warm climate bugs are damaging ever green plants

26 TERRESTRIAL AND FRESHWATER ECOSYSTEMS 1850 Raphael Island (St. Brandon) 1960 GLACIER D ARGENTIERES (French Alps)

27 IPCC - Sea Level Rise IPCC: average temperature of the global ocean has increased to depths of at least 3000 m and the ocean has been absorbing most of the heat added to the climate system. Such warming causes seawater to expand and is estimated to have contributed.42 mm yr-1 to the average sea level rise from 1961 to 2003, and 1.6 mm yr-1 from 1993 to 2003.

28 IPCC - Sea Warming observed changes in marine and freshwater biological systems are associated with rising water temperatures, as well as related changes in ice cover,salinity, oxygen levels and circulation. These include: shifts in ranges and changes in algal, plankton and fish abundance in high-latitude oceans; increases in algal and zooplankton abundance in high-latitude and high-altitude lakes; range changes and earlier migrations of fish in rivers. The uptake of anthropogenic carbon since 1750 has led to the ocean becoming more acidic with an average decrease in ph of 0.1 units.

29 Sea Surface Temperature - Regional Increase of ºC in tropical belt of SWIO

30 Direct Impacts Coastal inundation Intrusion into inland acquiferes Higher water level during extreme events Damage to coastal infrastructures Threat to inhabitation Very high impacts on economics and security Loss of marine resources, incl. fish

31 COASTAL INUNDATION

32 Global Warming & Sea Level Rise

33 Cyclonic Activities No definite trend in number of cyclones in SWIO However, intensification trend of cyclones steeper Gamede, Inlala & Jaya intensified at 1.5-2Ts in 12 hrs whereas normal = 1T in 24 hrs

34 Very Intense Tropical Cyclone GAFILO March 2004 During the past decade more and more intense cyclones are being observed in the South West Indian Ocean

35 Storm Surge

36 Beach Erosion

37 HUMAN HEALTH

38 OZONE HOLE(S)

39 HEAT WAVES INCREASE OF EVEN HALF A DEGREE GLOBALLY MAY TRANSLATE INTO INCREASES OF SEVERAL DEGREES IN URBAN AREAS. THIS IS AN IDEAL CONDITION FOR HEAT WAVES TO OCCUR.

40 RESPONSE MEASURES More efficient technological means Technology transfer-assist. from developped countries Research into high-yield crops Application of scientific means fo production incl. use of climate data Change in Habits

41 CONCLUSION Climate Change is one of the most serious threats to sustainable development: It has adverse Impacts on Food Security, Water Resources, Human Health, Economic Activities and the Environment. Remedial actions : NOW

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44 Thank You