A recent online article in the research forum Nature Communication caught our attention. It was to do with the cooling affects of irrigation in extreme periods of heat. We Australians are no strangers to extreme conditions. Our country experiences some of the most significant temperature extremes on the planet, not to mention extreme weather events including floods and bushfires.
But did you know that irrigation is known to have the unintended benefit of reducing and sometimes negating extreme temperatures?
This concept was discussed recently in detail in this article, Warming of hot extremes alleviated by expanding irrigation.
It is a fact that irrigation has expanded significantly over the 20th century throughout the developed and developing world. The study undertaken presented, as an example, that countries in South Asia, where substantial irrigation expansion had taken place, have warmed less over time when compared to areas with low or no irrigation rates.
A significant statement from the journal article was, “While global warming increases the likelihood of hot extremes almost globally, irrigation can regionally cancel or even reverse the effects of all other forcings combined.”
The idea that irrigation could have such a positive follow-on effect is very exciting for decision-makers in local councils around Australia as they look to increase the amount of useable green space. The concept that increasing local green space using intelligent irrigation systems could have the effect of cooling surrounding air temperatures on extreme hot days is profound. And certainly great news for residents.
As discussed in a previous blog the City of Melbourne has implemented an Urban Forest Strategy. A key aim of this strategy is to reduce the urban heat island effect by bringing temperatures down. Improving vegetation health and soil moisture through good irrigation will be crucial to achieving this.
We all appreciated that irrigation has the primary benefit of increasing greenery and thereby removing Co2 from the atmosphere. The notion that irrigation-induced cooling is a second level benefit of irrigation is definitely worth further investigation.
We urge the decision makers in Australia’s biggest cities and regional centres to consider how they could apply this exciting principle to their jurisdictions in 2020.