Climate Model Shows Australia’s Rainfall Decline Due To Human-Caused Climate Change

Australian Drought Result of Anthropogenic Climate Disruption (ACD)

Source:  NOAA Research

“NOAA scientists have developed a new high-resolution climate model that shows southwestern Australia’s long-term decline in fall and winter rainfall is caused by increases in man-made greenhouse gas emissions and ozone depletion, according to research published today in Nature Geoscience.

Australian Drought ACD

Australian Drought ACD

“This new high-resolution climate model is able to simulate regional-scale precipitation with considerably improved accuracy compared to previous generation models,” said Tom Delworth, a research scientist at NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton, N.J., who helped develop the new model and is co-author of the paper. “This model is a major step forward in our effort to improve the prediction of regional climate change, particularly involving water resources.”

“NOAA researchers conducted several climate simulations using this global climate model to study long-term changes in rainfall in various regions across the globe. One of the most striking signals of change emerged over Australia, where a long-term decline in fall and winter rainfall has been observed over parts of southern Australia. Simulating natural and human-caused climate drivers, scientists showed that the decline in rainfall is primarily a response to human-caused increases in greenhouse gases as well as a thinning of the ozone caused by human-caused aerosol emissions. Several natural causes were tested with the model, including volcano eruptions and changes in the sun’s radiation. But none of these natural climate drivers reproduced the long-term observed drying, indicating this trend is due to human activity.

“Southern Australia’s decline in rainfall began around 1970 and has increased over the last four decades. The model projects a continued decline in winter rainfall throughout the rest of the 21st century, with significant implications for regional water resources. The drying is most severe over southwest Australia where the model forecasts a 40 percent decline in average rainfall by the late 21st century.
“Predicting potential future changes in water resources, including drought, are an immense societal challenge,” said Delworth. “This new climate model will help us more accurately and quickly provide resource planners with environmental intelligence at the regional level. The study of Australian drought helps to validate this new model, and thus builds confidence in this model for ongoing studies of North American drought.”
The new paper, Regional rainfall decline in Australia attributed to anthropogenic greenhouse gases and ozone levels, is available online.”

To read a Research Highlight on the paper, please go to NOAA’s Geophysical Fluid Dynamics Laboratory website:


Deer Decline in Western U. S. as Drought Continues

Deer in Arizona

Mule Deer Mother and Daughter at Coldwater Farm (Garry Rogers April, 2014)

Mule Deer Mother and Daughter at Coldwater Farm (Garry Rogers April, 2014)

The Arizona deer “harvest” is declining as the drought deepens.  Though the Arizona Game and Fish Department now places no limits on the number of deer hunting licenses sold, the number of deer that hunters kill is shrinking as the deer population shrinks.

Last year, wildlife managers warned that deer would start showing up in towns where there are irrigated lawns and gardens.  That certainly was true for Coldwater Farm where the first repeated deer visit occurred and a fawn was born.  More deer are coming to the Farm this year, and we are expecting more births.

The deer are coming for water and to eat our flowers, vegetables, and weeds.  We are delighted, and would rather see deer than tomatoes.  If necessary, we can fence our garden. There are two problems:  1) we do not want to spoil the deer ability to live in the forest when the drought fades (if it does).   2) Some of our neighbors prefer tomatoes over deer and may call Animal Control (Wildlife Services?) to remove the deer.

Problem 1) is insignificant.  Because of local geology, the river has carried surface water through the site of Coldwater Farm for tens of thousands of years.  Deer have probably come for the water and riparian vegetation many times in the past and returned to the chaparral and forest when rains returned.

Problem 2) is more significant.  Already two neighbors report “shooing” deer from their garden.  Climate forecasts predict that our drought will continue for many years.  Deer could join the smaller mammals to become a permanent part of our small town biosphere.  How long before Humans demand that the deer are removed?  What will I have to do to protect their right to water and food?

Deer in Colorado

“The number of deer in Colorado and other parts of the West is rapidly declining, including a 36 percent drop among mule deer in the Centennial State from 2005 through last year, and a reported drop of at least 10 percent throughout the region.

“Brutal winters followed by extremely dry summers, loss of habitat due to commercial and residential development and predators like coyotes and mountain lions are factors in the decline, Matt Robbins, spokesman for Colorado Parks and Wildlife, told

“It’s a culmination of things,” Robbins said. “Weather has absolutely been a factor; we’ve had very harsh winters and then very dry summers, and we’re always very conscious of chronic wasting disease, loss of habitat, highway mortalities, predators and oil and gas development.”