Definition+-+What+is+climate+change?

Australia and the globe are experiencing rapid climate change. Climate change is any long-term significant change in the natural variation of weather on the earth. Climate including temperature has always changed on earth, but climate change reflects abnormal variations to the expected climate on earth caused by human activity. Over the last ten years, the debate has centered on the cause of climate change; whether it is a natural variation in the earth’s climate, or whether human activities are at the base of this change, causing more unpredictable changes to the weather patterns on earth including Australia. It is now well established, that the 13 warmest years in the last 125 years have all occured since 1990. Since the middle of the 20th century, Australian temeratures have, on average, risen by about 1 ° C with an increase in the frequency of heat waves and a decrease in the number of frosts and cold days. In Australia the climate has changed, so that there is greater warming in eastern and central Australia with more extremely hot days and fewer frosts. The past 12 years have been very unusual - very wet in the north and west of Australia and very dry over southeast Queensland, southern New South Wales and South Australia, Victoria, eastern Tasmania and southwestern Western Australia. Rainfall patterns have also changed - the northwest has seen an increase in rainfall over the last 50 years while much of eastern Australia and the far southwest have experienced a decline.

__Figure 1 Trend in annual total rainfall in Australia__



__Figure 2 Trend in annual total rainfall in Australia indicating areas of unusual rainfall patterns__

It is anticipated that by 2030, rainfall patterns will decrease by 0 to -10% (up to 10% less than what it is now) in southern Australia. This will increase the frequency of droughts in the south and increase bush fires. In northern Australia it is anticipated that rainfall will increase up to 5% and in some parts decrease by 10%. There will be heavier rains storms in summer and autumn and little change in winter and spring.

__Figure 3 Median percentage rainfall change in Australia __ Australian average temperatures have increased 0.9°C since 1950, with significant regional variations. The frequency of hot days and nights has increased and the frequency of cold days and nights has declined. It is predicted that by 2030 there will be 0.6-1.5°C, by 2070 this will be between 1.0-2.5°C warmer if in a low emission scenario, but if the emission scenario is high, warming in Australia will be between 2.2-5° C. Small changes on average temperature have a large affect on extreme daily temperatures. Since 1960 there has been an increase in the average number of hot days and very hot days (__Figures 4 and 5__) __Figure 4 Mean annual anomalies of temperatures since 1910 to 2009.__

 __<span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;">Figure 5 Average number of very hot days since 1910 to 2009. __ <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive; msobidifontfamily: Arialmso-ascii-theme-font;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;"> <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;"> It is predicted that there will be an increase in future extreme temperatures; an increase in heat waves and fires and less frost and snow (__Table 1__)

__Table 1 Future Extreme Temperatures__ <span style="font-family: 'Calibri', 'sans-serif'; text-align: center; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"> || **<span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">2070 Low emissions ** || **<span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">2070 High Emissions ** ||
 * **<span style="display: block; font-size: 140%; font-family: 'Comic Sans MS', cursive; text-align: left;">Location ** ||< <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">**<span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">Present ** **<span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;">1971-2000 ** || **<span style="display: block; font-size: 140%; font-family: 'Comic Sans MS', cursive; text-align: left;">2030 Mid range emissions **
 * <span style="display: block; font-size: 160%; text-align: right; msobidifontfamily: Arialmso-ascii-theme-font;">**__<span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">Canberra __** ||
 * <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive; msoasciithemefont: minor-latinmso-hansi-theme-font;">Days over 35° C

|| <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">5

|| <span style="font-family: 'Calibri', 'sans-serif'; text-align: right; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"><span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;">7-10

|| <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">8-14

|| <span style="font-size: 14pt; font-family: 'Calibri', 'sans-serif'; text-align: right; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"><span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;">12-26

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 * <span style="font-size: 14pt; font-family: 'Calibri', 'sans-serif'; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">Days below 0°C

|| <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">60

|| <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;">42-51

|| <span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">36-48

|| <span style="font-family: 'Calibri', 'sans-serif'; text-align: right; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"><span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive;">20-39

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 * <span style="display: block; font-size: 160%; text-align: right; msobidifontfamily: Arialmso-ascii-theme-font;">**__<span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">Adelaide __** ||
 * <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;"><span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive; msoasciithemefont: minor-latinmso-hansi-theme-font;">Days over 35° C

|| <span style="font-family: 'Calibri', 'sans-serif'; text-align: right; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"> <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">17 || <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">21-26

|| <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">24-31

|| <span style="font-family: 'Calibri', 'sans-serif'; text-align: right; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">29-47

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 * <span style="font-family: 'Calibri', 'sans-serif'; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial;"><span style="font-size: 14pt; font-family: 'Comic Sans MS', cursive; msoasciithemefont: minor-latinmso-hansi-theme-font;">Days over 40° C

|| <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">2

|| <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left; msoasciithemefont: minor-latinmso-hansi-theme-font;">3-5

|| <span style="font-family: 'Calibri', 'sans-serif'; text-align: right; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: Arial; msobidifontfamily: Arial; msoasciithemefont: minor-latin; msohansithemefont: minor-latin;"><span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">3-6

|| <span style="display: block; font-size: 14pt; font-family: 'Comic Sans MS', cursive; text-align: left;">5-13 ||