I found a fascinating article from the Australian Bureau of Meteorology (BOM) online the other day. I think it’s quite an important one as it described a phenomenon I’ve been noticing in my rainfall data for a while. Namely, that our growing season rainfall has been trending lower for quite some time. Our 20 year growing season rainfall (GSR) average is a full 50mm below the long term average. In years like last year it’s the difference between a healthy profit and breaking even or worse.
This was one of the more relevant quotes to me, as by a stroke of luck I started farming in 2010, which turned out to be an exceptionally wet year.
The two La Niña years (2010& 2011) saw excessive rainfall during the warm season, but did not reverse the pattern of poor cool season rainfall that was the major feature of the Millenium Drought. The early cool season rainfall during these two years (April to July) shows the pattern of below average rainfall in the southwest, southeast and parts of the east still persisted.
The bureau then links these changes to climate change and in particular, anthropogenic warming.
While natural rainfall variability in Australia is large, and influenced strongly by the El Niño-Southern Oscillation, based on current research it seems likely that drying across southern Australia cannot be explained by natural variability alone.
I’m not smart enough to know why our climate is changing. Only that it is. I just know that we’ve just been declared in another El Nino, and while this doesn’t guarantee a drought, it makes this drying trend much more likely to continue. We farmers will just have to deal with it.