Human impacts and changes in the coastal waters of south China

- Hong Kong-Shenzhen experienced rapid population and economic growth since 1990.
- Human impacts caused local changes at much faster rates than the global estimates.
- Temperature increased 0.060 ± 0.006 °C per year in 1990-2012.
- Local water level increased by 4.4 ± 1.1 mm per year in the same period.
- Surface pH declined from 8.2 to 7.7 in the same period.

Human impact on the environment remains at the center of the debate on global environmental change. Using the Hong Kong-Shenzhen corridor in south China as an example, we present evidence that rapid urbanization and economic development in coastal areas were the dominant factors causing rapid changes in coastal waters. From 1990 to 2012, coastal seawater temperature increased ~ 0.060 °C per year, sea level rose 4.4 mm per year and pH decreased from 8.2 to 7.7, much faster than global averages. In the same period, there were exponential increases in the local population, gross domestic product and land fill area. Empirical analyses suggest that the large increase in the population affected local temperature, and economic development had a major impact on local pH. Results also show that pH and temperature were significantly correlated with local sea level rise, but pH had more predictive power, suggesting it could be considered a predictor for changes in local sea level. We conclude that human activities could significantly exacerbate local environmental changes which should be considered in predictive models and future development plans in coastal areas.

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