Wellington drowning: once a century floods now come twice a year — study links it to human activity

Since 1900, the frequency of extreme coastal water levels has increased fourfold. Events with a 1% annual probability have become at least ten times more frequent by 2005. Last week, the New Zealand capital ended a state of emergency after a heavy swell warning. Scientists demand an urgent revision of flood protection plans.

As reported by CCTV+, human driven sea level rise has significantly increased the likelihood of coastal flooding in New Zealand's capital, Wellington: floods that used to occur once every 100 years now happen about twice a year, new research shows. The study, published in Nature Climate Change, found that sea level rise has increased the frequency of extreme coastal water levels about fourfold since 1900 globally. Events that historically had a 1% annual probability have become at least ten times more frequent in many locations by 2005.

Last week, Wellington lifted a local state of emergency in some parts of the capital following warnings of a heavy swell along the south coast and the southern Wairarapa region. Researchers warn that continued sea level rise will further increase coastal flood risk, stressing the need to update flood management planning and adaptation measures, especially in low lying coastal areas.

Causes of sea level rise: melting glaciers and thermal expansion of the ocean due to global warming driven by greenhouse gases. Wellington is a low lying coastal city, making it particularly vulnerable. The Nature Climate Change study is highly authoritative. The "once in 100 years" figure refers to an event with a statistical probability of 1% per year. That same event now has a 200% annual probability (twice a year).

When a "century" shrinks to "half a year," nature stops joking. Wellington — a capital where waves are already knocking at the door. What was a catastrophe for great grandfathers is now routine for grandchildren. Scientists do not guess; they measure: a fourfold increase in frequency, a tenfold acceleration. All within one generation's lifetime. Some will say "cycles," but the charts stubbornly point to humans. While politicians argue, the sea level rises. If flood maps are not revised now, seagulls will soon nest on the roofs of former government buildings. The choice is not between adaptation and inaction, but between timely adaptation and catastrophe.