Future Big Droughts May Be Worse Than We Think – New Zealand’s Past Shows Why
New research indicates that New Zealand's historical droughts, particularly those before 1950, were significantly more severe than recent events. Experts warn that current climate risk assessments may underestimate future drought intensity as rising temperatures threaten to push environmental conditions beyond living memory.
Highlights
- •New research highlights that past droughts in New Zealand, particularly before 1950, were more severe than recent events.
- •Current risk assessments relying on data since the 1970s may underestimate the potential scale of future meteorological droughts.
- •Significant historical dry periods, such as the 1914-15 and 1907-08 events, provide critical benchmarks for climate planning.
- •Rising global temperatures are expected to worsen future dry spells, necessitating a re-evaluation of long-term climate risk strategies.
For an agricultural nation like New Zealand, facing future droughts is a growing concern that may be more severe than current models suggest. As the planet continues to warm, the Climate Change Commission has warned that these arid events are expected to intensify, particularly affecting the northern and eastern regions of the country. Historical analysis indicates that the challenges posed by these dry spells—such as parched pastures, depleted water reservoirs, and increased economic pressure—could be more extreme than many recent assessments have anticipated.
Rethinking Historical Drought Patterns in New Zealand
Recent decades have seen significant economic disruptions caused by water scarcity. For example, the extended 2007–08 drought led to a sharp rise in silage costs, costing the national economy billions. Furthermore, the 2012–13 event, which impacted the entire North Island, reduced national economic output by approximately 0.7%. However, while these recent occurrences are used by the Reserve Bank to model worst-case scenarios for agricultural lending, new research suggests that looking only at the last few decades provides an incomplete picture of potential risks.
By analyzing meteorological data that extends back well into the 19th century, researchers have identified several extreme droughts occurring before 1950 that were far more severe than those experienced in recent memory. Specifically, a massive multi-year dry spell from mid-1914 through early 1915 ranks as one of the most intense meteorological events in the instrumental record. Similarly, the 1907–08 summer season saw more widespread rainfall deficits than any other period in the recorded history of New Zealand.
The discrepancy between these historical extremes and contemporary drought experiences is significant. Relying primarily on data from the 1970s onward may lead to an underestimation of the true variability in weather patterns that the region is capable of enduring. As climate change further accelerates, bringing higher temperatures that exacerbate soil moisture loss and evaporation, the risk of facing conditions beyond living memory increases.
Ultimately, this research serves as a critical reminder that past events, even those occurring over a century ago, offer vital insights into future environmental threats. Integrating this broader historical perspective into modern risk assessments is essential for robust long-term planning. Ignoring these historical benchmarks could leave the nation unprepared for the scale of moisture deficits that are possible in a warming climate.
