Unprecedented flooding in New Zealand and California
Sidney Watson investigates the unprecedented flooding in New Zealand and California, discussing past and future frequency of extreme weather and its mitigation.
In late December and early January, California was hit with over three weeks of heavy rainfall, generating flooding that left 20 dead and nearly 25,000 people displaced from their homes. This rainfall was the result of a sequence of nine high precipitation storms called “atmospheric rivers” that hit the state, overwhelming flood protection measures and causing landslides, flooding homes, toppling trees and generating blackouts in parts of the state.
More recently, across the Pacific, New Zealand’s North Island was also hit with flooding that Prime Minister Chris Hipkins called a “one-in-100-year weather event”. Four people have been reported dead with hundreds more left wounded or displaced in only a few days due to record volumes of rainfall hitting the capital, Auckland, and the surrounding region. Though the rain has largely subsided, the Auckland and Thames-Coromandel regions remain under a State of Emergency as officials warn of unsafe roads and infrastructure alongside the continued risk of landslides and sinkholes.
Exacerbating these effects is also the often-unseen psychological cost of flooding and other extreme weather events.
Other than the tragedy of lives lost and homes and livelihoods destroyed, these events have also generated huge economic costs, which will only grow as time goes on and the full damages are accounted. Officials in California currently report damages at over $30 billion, and while the full cost has not been tallied in New Zealand, 20,000 insurance claims have already been lodged, according to a spokesperson for the Insurance Council of New Zealand.
Moreover, extreme flooding events like these can also generate inflationary pressures as certain goods and services become scarce or unavailable due to the destruction. In New Zealand, with roads, homes and agricultural land destroyed, economists have already warned of potential price spikes in fresh produce, rent, construction and transport.
Exacerbating these effects is also the often-unseen psychological cost of flooding and other extreme weather events. According to a study published in 2015, floods have a “potentially negative impact on mental health, with increasing levels of PTSD, anxiety, and depression”, which can negatively impact individuals and communities even after the physical damage is repaired.
While likely made more extreme by Global Warming, the flooding in California was somewhat more predictable.
Reflecting on the recent flood, the New Zealand’s PM named Climate Change as a central driver, stating “Climate Change is real, it is with us.” Indeed, with the country reporting “extreme weather related [insurance] claims” at a record high for the third year in a row, it is difficult to ignore the connection between global warming and increasingly damaging weather events.
While likely made more extreme by Global Warming, the flooding in California was somewhat more predictable. Data put out by the US Geological Survey (USGS) indicates that the atmospheric rivers experienced by California in recent months were unusual but not unprecedented – reflecting on floods of an even greater magnitude that hit the state as far back as 1861-62.
However, with California still recovering from the hottest drought in its recorded history in 2012-2016, extreme flooding is far from being perceived as “normal”. Indeed, recent research builds on the USGS data, stating that “climate change has already doubled the likelihood of an event capable of producing catastrophic flooding”, and as warming continues, the likelihood of further catastrophic flooding will only increase.
The question, therefore, remains: how do we reduce the likelihood of events like these happening again and how can we mitigate their impact when they do strike?
On the issue of reducing the likelihood of flooding, the solution is clear: reduce carbon emissions to slow global warming. The IPCC’s reporting indicates that while the world many never return to pre-industrial revolution levels of extreme weather events, the likelihood of a 10-year flash flood-level storm occurring in a given year doubles if the world reaches 2 degrees warming, so every fraction of a degree lower counts.
Nonetheless, with flooding likely to continue, the eyes of many policymakers, scientists and leaders are turned towards mitigating the negative impacts of flooding. In New Zealand, existing flooding policy has been updated to include a more long-term approach that anticipates increased flooding due to climate change. In 2019 a report was also released that called for a $150 million investment per year in flood protection across the country – a demand that has been renewed in response to the flooding.
In the future, past methods of response and recovery will not be enough: governments must increasingly make bold investments and take pre-emptive action to adapt to the changing climates they face.
In California, the policy directive is less clear: in a state which more commonly deals with drought, much of the investment tends to be directed at drought-mitigation efforts rather than flood protection. However, more recently, many have put forth suggestions for increased flood protection and greater public education on flood safety. Andrew Kruczkiewicz, a senior staff associate at the Columbia Climate School’s International Research Institute for Climate and Society, asserts that effective communication is key to mitigating the impacts of flooding, not only between leaders and citizens but also between scientists and policymakers, stating: “without the translation into action, the potential value of ‘skillful’ forecasts goes untapped or under-utilized.”
Regardless of the methods used, as these events increase in frequency and magnitude due to Climate Change, past methods of response and recovery will not be enough: governments must increasingly make bold investments and take pre-emptive action to adapt to the changing climates they face.
