Extreme Droughts

In the United States, drought conditions worsened across South Central Texas, harming agricultural production in the region. As of July 28th 2009, moderate to severe drought persisted across much of California and Wisconsin, parts of Nevada, New Mexico, Oklahoma, and portions of the Hawaiian Islands. Overall, about 11 percent of the U.S., including Alaska, Hawaii, and Puerto Rico, experienced moderate to severe drought.

In South Central Texas, drought conditions continued to deteriorate through July, with most of the region experiencing exceptional drought. Average temperatures were generally above-to-well above normal during this period, with many areas reaching the triple digits on consecutive days, including a record high temperature of 109°F (43°C) set at Poteet, Texas on July 6th. Conditions severely impacted crops and livestock production, as crops wilted and farmers were forced to cull their cattle. According to reports, over 60 percent of beef cows in the state are located in counties in extreme to exceptional drought. Experts at Texas A&M University estimate that agricultural economic losses could surpass the 4.1 billion dollar mark set during the last drought in 2006.

For the 24-month period from August 2007 to July 2009, serious to severe rainfall deficiencies remain evident across much of southeast Australia and parts of central Australia. These regions experienced some average to above average rainfall during the final months of both 2007 and 2008, as well as through the most recent autumn. However, most months through the period were drier than the long-term mean, especially during the growing seasons. Both 2007 and 2008 were classified as positive Indian Ocean Dipole (IOD) years, which is likely to have contributed partly to the low winter and spring rainfall recorded across parts of southern Australia during both these years.

Very long-term rainfall deficiencies outside of the drought periods discussed above persist across parts of southern and eastern Australia. Most notably, rainfall has been below average across much of southwest and southeast Australia since 1997, while the Murray-Darling Basin has experienced below average rainfall since 2002.

The deficiencies discussed above have occurred against a backdrop of decade-long rainfall deficits and record high temperatures that have severely stressed water supplies in the east and southwest of the country. The combination of record heat and widespread drought during the past five to ten years over large parts of southern and eastern Australia is without historical precedent and is, at least partly, a result of climate change."





Below is a chronology of extreme droughts recorded in Australia;

1864-66 All States affected except Tasmania.

1880-86 Southern and eastern States affected by extreme droughts.

1895-1903 Sheep numbers halved and more than 40 per cent loss of cattle. Most devastating in terms of stock losses.

1911-16 Loss of 19 million sheep and 2 million cattle to extreme drought.

1918-20 Only parts of Western Australia free. 1939-45 Loss of nearly 30 million sheep between 1942 and 1945.1963-68 Widespread and longest drought in arid central Australia:

1958-67. The last two years saw a 40 per cent drop in wheat harvest, a loss of 20 million sheep, and a decrease in farm income of $300-500 million.

1972-73 Mainly in eastern Australia.

1982-83 Total loss estimated in excess of $3000 million. Most intense drought in terms of vast areas affected.

1991-95 Average production by rural industries fell about 10 per cent, resulting in possible $5 billion cost to the Australian economy, $590 million drought relief provided by the Commonwealth Government between September 1992 and December 1995.

2002-08 The current extreme drought in Australia is the worst in 100 hundred years. About 65 percent of Australia's viable agricultural land is currently in drought, with 23,000 farming families on some form of drought relief payments. The Australian government has announced more than A$1 billion in drought aid in the past fortnight, taking government drought support to more than A$3 billion since 2001.

Water storages in the Murray-Darling Basin are very low. The Murray-Darling Basin is located in the south-east of Australia and covers an area of 1.05 million square kilometres or 14% of Australia. The Murray-Darling is Australia’s longest of river systems and ranked fifteenth in the world.

The Australian government reports that the 2007-08 water availability outlook for the Murray-Darling Basin system is serious and still deteriorating. Inflows received so far in 2007-08 are still well below average and are among the lowest on record

Bureau of Meteorology head of climate analysis David Jones said the 12-year drought that was devastating southwest Western Australia, southeast South Australia, Victoria and northern Tasmania was "very severe and without historical precedent".

Drought has gripped the Murray-Darling Basin since late 2001. It has worsened this year, as rainfall totals for the past three years have set record lows in many regions, including many critical to the Murray River.

Dr Jones said the rainfall figures were similar to the severe drought that lasted from 1939 to 1945, and the Federation drought, which ran from 1895 to 1903.

"Those three droughts, in terms of rainfall, are comparable," he said. "But this drought is a lot hotter than those two previous droughts. And those two droughts finished, whereas this one is continuing."

Page updated 7 August 2009

Enter your search terms Submit search form   Web www.global-greenhouse-warming.com

go from Extreme Droughts back to Extreme Weather