What is Climate Change?

Climate change is the changing of weather patterns over a long period of time. This can include the change in average rainfall per year over the course of ten years, or the change in average temperature per year over the course of ten years. Climate change is one of the most pressing issues of our time, and is especially concerning when considering the protection of estuaries.

Over the past few decades, the Earth has experienced a drastic rise in temperature. This rise in temperature is mostly due to the increased carbon dioxide emissions created by burning fossil fuels for human activities such as driving cars, producing electricity and factory production. Once the carbon dioxide is released into the air, it rises up into the atmosphere. This increased amount of carbon dioxide, along with other greenhouse gasses (i.e. methane and nitrous oxide) causes a worldwide increase in temperature, affecting habitats such as estuaries. According to NASA, for 650,000 years atmospheric carbon dioxide levels never exceeded 300 parts per million. Since the year 1950, atmospheric carbon dioxide levels have increased from about 300 parts per million to more than 400 parts per million. (For more information, visit http://climate.nasa.gov/evidence)

(Diagram borrowed from http://climate.nasa.gov/evidence)  

Climate Change Impacts on Estuaries

Estuaries are under constant danger of rising sea levels. There are two kinds of sea level rise: eustatic and relative. Eustatic sea level rise refers to an increase in the volume of the world's waters casued by the melting of polar ice caps. Relative sea level rise occurs when land masses elevate relative to the sea level.


(Picture from https://www.climate.gov/news-features/features/superstorm-sandy-and-sea-level-rise

This increase in water levels can do a lot of damage to estuaries. Plants that are meant to be above the water line are now being drowned, and there is ever-decreasing light availability to submerged aquatic vegetation. Sea level rise also increases the amount of flooding and erosion of coastal areas. If this trend continues, the erosion of beaches will become very severe, destroying dunes that are essential to the prevention of landslides and slumping.

Saltwater intrusion is another damaging effect of sea level rise. As the water level rises, saltwater stretches further inland, increasing the salinity of water that was once fresh. This can put stress on plants and animals and may even cause a disappearance of certain species when the salinity level reaches above their tolerance.

Ocean acidification is one of the most serious effects of increased carbon dioxide levels. Ocean acidification happens when carbon dioxide in the air is absrobed by the saltwater and consequently turns the water acidic. This causes organisms made from calcium carbonates (like coral) a lot of harm because calcium carbonates dissolve in acidic substances.

Sea level rise can also push species out of the area in search for better habitats, which may cause invasive species to take over certain areas. This is a major problem because when invasive species take over, native species begin to suffer and die out.  

Restore America's Estuaries Position on Climate Change

Read Restore America's Estuaries current position statement on climate change here.