Weather Gone Wild

By: Chris O’Connor BHort GradDipSustAgric

The Climate Council released a report on 5 Feb 2019 entitled Weather Gone Wild: Climate change – fuelled extreme weather in 2018.

The report highlights some worrying trends, none of which are really surprising; namely that both on a global and local scale temperatures in general are increasing and that extreme weather events are occurring more frequently and with greater intensity than in previous years.

Extreme weather events are manifested through extreme temperatures and heatwaves, drought, bushfires, intense rainfall and flooding, cyclones and storms. Apart from the increases in individual events we are witnessing compounded extreme events, where we see multiple events occurring in short spaces of time, each other leading to increased impacts. For example, drought affected areas being subject to extreme rainfall events can see greater impacts to the soil through erosion or drought affected areas in combination with thunderstorms are more at risk of bushfire events.

The cause of this increasing trend of extreme weather is climate change. Industry is well placed to help ameliorate the impacts of climate change through its products and this is a great opportunity for industry to promote and support. However, in the meantime industry is susceptible to the impacts of climate change as manifested through extreme weather events.

What does this mean for our industry?
Given the increasing frequency and intensity of extreme weather events, it is highly likely that the industry will be significantly impacted moving into the future.

Beyond the obvious impacts of extreme weather events such as direct damage to infrastructure, increased costs to business (insurance, crop losses, lost time) and personal impacts to staff and owners, there are a range of other impacts which we need to consider and plan for.

Extreme weather results in more downtime for staff leading to lost productivity. This can be seen during high temperature periods or extreme rainfall events where it is not suitable for staff to be engaged in activity in the field.

Due to these events staff are also more frequently engaged in non-core production work for example cleaning up after storms. This results in increased labour costs for the business and less time available to be used on core production tasks.

Longer term it may also be more difficult to attract staff, especially good quality staff, to roles which require more frequent exposure to weather extremes such as high temperatures.

It goes without saying but climate plays such an import part in our industry due to the direct impact it has on plant production. The changes we are seeing to climate are being manifested through extreme weather events and more continuously via increased temperatures. This in turn has an impact upon the suitability of crops grown. For example if a certain number of chilling hours are required for a crop to flower, then this may require the grower to implement artificial chilling, replacement with an alternative crop (if one is available) or the acceptance of constrained availability.

The timing of crops is also affected by the temperature, and crops which were traditionally available at a certain time of year are no longer available. Perhaps most importantly extreme temperatures can negatively affect growth rates of plants. All plants have an optimum temperature range to facilitate growth, which varies from species to species, but in general plant growth accelerates as temperature increases, up to a point. Beyond this point the growth rates slow down as photosynthetic activity decreases. Continuous high temperatures such as those experienced during heatwaves can therefore stress plants and retard the growth rates of stock in turn requiring more time to achieve a saleable crop.

As a result of these impacts individual businesses should give thought to how they will adapt. Key issues include if they should invest in increased protected cropping facilities in order to abate some of the extremes.

Hand in hand with extreme high temperatures is drought. Considering this thought should be given to how businesses will secure water and how it will use water. This requires a review of your irrigation systems and water reuse processes, for example are your pumps working efficiently? Is your system regularly maintained? How long has it been since your irrigation system was reviewed and is it still suited to your production needs?

Thought should also be given to the changing rainfall patterns and its impact on the business. Considerations may include if your water capture facilities are able to cope with intense rainfall events and maximise water storage on site? This includes the serviceability of ground surfaces on site, drains and dams.

Increasingly extreme weather events are also having an impact upon the markets which the industry services. Drought certainly affects the levels of purchasing, however the choice of plant purchased may also be affected. In previous droughts xeriscaping was a market response which remains so today. Additionally, we are seeing an increase in indoor plants driven by a range of reasons from fashion to increased focus on urban greening, however these would be an appropriate alternate or complimentary crop line.

Increased consideration should also be given to the suitability of the crops grown to the environment they are going into. Considerable work is being undertaken in this space for instance the levy funded Which Plant Where project is examining which plants are most likely to thrive under the extreme climates which Australian cities will likely face in the future.

Broadly thought should be given to changes happening in other sectors of horticulture as well. For instance, other horticultural sectors are branching into protected cropping, in order to reduce their business risk. This may well provide the facilities and opportunity for businesses in these sectors to undertake their own propagation work, thereby reducing the market for existing players in the nursery sector.

We’ve touched upon how climate is intrinsically linked to plant growth and so it should be no surprise that the prevalence of plant pests is closely linked to climate as well. Driven by climate change, pest population geographic ranges will change, areas which previously could not support specific pests will become suitable environments. In areas where cooler winters were in the past able to curb populations, higher temperatures will allow pests to survive the winter and continue to thrive.

Changed climate will also facilitate the successful introduction and establishment of new pests. This is achieved not only through providing a climate which is favourable to the pest but also by providing a vehicle to get it there. For instance, wind has been identified as a likely cause of spreading myrtle rust to islands in the pacific and cyclones have been known to spread insects such as psyllids over long distances.

For industry the changing pest environment will put increased pressure upon growers. To manage this, growers should take a proactive approach and ensure that they conduct regular monitoring of their crops and production site. This regular monitoring will provide a timely alert of changes to the pests present and provide more time for growers to adapt.

For growers the BioSecure HACCP program provides structured guidance on crop monitoring and site surveillance, and biosecurity management in general. As such it is a highly useful tool in assisting growers to manage their biosecurity obligations.

Social Licence
Both as an industry and as individual businesses we operate within the constraints of a range of legislative requirements. However, our industry and businesses are also permitted to operate through social licence. Social licence is hard to define but is the ongoing acceptance and or approval by the community of a particular activity. This acceptance or trust by the community has very real and tangible impacts upon an industry or businesses ability to be successful and hence reflects considerable business risk.

In the past social licence was quite locally focused however, as social media has expanded, and the world has become increasingly globalised and connected the influence and importance of social licence has grown.

A recent example of social licence influencing the industry is the discussion around pesticides both in the past and more recently. Likewise more broadly in horticulture is discussion around worker conditions especially for those working under visa’s.

Given that climate change, as expressed through severe weather events, is becoming ever more visible, businesses and industries which are not taking steps to manage their impacts upon climate will fall under increasing pressure from society. This will see a negative impact to their social licence and will limit the ongoing success of the business or industry.

For the nursery industry our work in promoting the 202020 Vision has certainly contributed positively to our industry social licence however we can still be at risk of damaging our positive social licence if we fail to act accordingly around climate change.

Further reading
Energetics (2018) Is ‘social licence to operate' the hard science? Sourced from
Steffan, W. Dean, A. & Rice, M. (2019) Weather gone wild: climate change fuelled extreme weather in 2018 Climate Council Sourced from