Ocean acidification
18
Friday, December 18, 2015
|
CONFRONTING CLIMATE CHANGE
Ocean acidification
Before the widespread use of fossil fuels, there was a natural equilibrium between carbon dioxide in the atmosphere and ocean chemistry. Marine organisms evolved to adapt to that balance; human-produced carbon dioxide is disrupting it. What we can do
One-quarter of human-produced carbon dioxide dissolves into the ocean, changing its chemistry. CO2
Half of humanproduced carbon dioxide leaves the Earth’s atmosphere, keeping the problem of global warming from being far worse.
+
+ HUMANPRODUCED CO2
One-quarter of human-produced carbon dioxide is used by land plants through photosynthesis.
CO2-3
H 2O
Carbon dioxide
Water
Carbonate ion
= 2 HCO3 Two bicarbonates
The way to slow down the trend of ocean acidification is to reduce the amount of carbon dioxide released into the atmosphere. That means switching from fossil fuels (coal, oil, gasoline and natural gas) to clean energy (wind and solar). Because carbon dioxide is absorbed by the oceans around the world, the problem requires a global solution. If we stopped releasing carbon dioxide into the atmosphere today, the oceans would slowly return to their natural equilibrium again, but it could take hundreds of years.
How it happens Carbon dioxide reacts with seawater to produce carbonic acid, which makes the oceans more acidic. Carbonic acid also depletes carbonates, needed by many sea creatures to build shells and skeletons. Human-produced carbon dioxide raises the level of carbonic acid in the ocean.
Why it matters
Ocean acidification is not directly caused by climate change, but it does occur in parallel with global warming. Both phenomena are caused by increasing carbon dioxide
in the atmosphere, which is primarily the result of burning of fossil fuels (coal, gas and oil).
Many sea creatures including corals, shellfish and lobsters, need carbonate to build their protective calcium carbonate shells and skeletons. With lower levels of carbonate in the oceans, they expend more energy making shells and less energy feeding and growing. Human-produced carbon dioxide dissolving in seawater (along with the chemical reaction that removes carbonate) creates higher ocean acidity (lower pH), which in turn can dissolve shells. Scientists surmise that if sea creatures can’t produce their shells and skeletons as quickly as the acidic ocean waters dissolve them, the populations of these animals could drastically decline. Many types of plankton – the basic building block for the ocean’s food chain – also need carbonate to make protective shells. Losing these organisms would disrupt the ocean food chain.
Immediate and long-term impact Ocean acidity is harming the ability of reef-building corals to produce their protective skeletons. Researchers say that by the end of this century, coral reefs may erode faster than new coral formations can be created at many locations in the tropical oceans.
Oysters along the U.S. Pacific Coast are already having difficulty in changing from their floating larval stage to their shell-building life on the sea bottom. This is naturally affected by upwelling of deep water, which is more acidic than surface water. Surface acidification will likely exacerbate the stress on marine life. (There are likely other stressors involved, including changes in salinity, predator populations and oxygen levels.)
Tests on pteropods (tiny floating sea snails) show that under the conditions expected by the year 2100, shells will dissolve in 45 days. These pteropods are a food source for larger ocean creatures, including young salmon.
Sources: NOAA/Pacific Marine Environmental Laboratory; Mark Altabet, professor at UMass Dartmouth’s School of Marine Science and Technology, NASA, Global Wind Energy Council FRED MATAMOROS AND GABRIEL UTASI/GATEHOUSE MEDIA
Tips to help 1. Support clean energy to reduce dependence on fossil fuels.
2. Buy local and go organic. Organic farmers return carbon to the soil; buying local food reduces fossil fuels used for transportation.
3. Reduce overall energy consumption. See tips on Page 38.
An onshore wind turbine with a capacity of 2.5 MW can produce more than 6 million kWh in a year enough to supply 1,500 average EU households with electricity.
Friday, December 18, 2015
|
CONFRONTING CLIMATE CHANGE
Ocean acidification
Before the widespread use of fossil fuels, there was a natural equilibrium between carbon dioxide in the atmosphere and ocean chemistry. Marine organisms evolved to adapt to that balance; human-produced carbon dioxide is disrupting it. What we can do
One-quarter of human-produced carbon dioxide dissolves into the ocean, changing its chemistry. CO2
Half of humanproduced carbon dioxide leaves the Earth’s atmosphere, keeping the problem of global warming from being far worse.
+
+ HUMANPRODUCED CO2
One-quarter of human-produced carbon dioxide is used by land plants through photosynthesis.
CO2-3
H 2O
Carbon dioxide
Water
Carbonate ion
= 2 HCO3 Two bicarbonates
The way to slow down the trend of ocean acidification is to reduce the amount of carbon dioxide released into the atmosphere. That means switching from fossil fuels (coal, oil, gasoline and natural gas) to clean energy (wind and solar). Because carbon dioxide is absorbed by the oceans around the world, the problem requires a global solution. If we stopped releasing carbon dioxide into the atmosphere today, the oceans would slowly return to their natural equilibrium again, but it could take hundreds of years.
How it happens Carbon dioxide reacts with seawater to produce carbonic acid, which makes the oceans more acidic. Carbonic acid also depletes carbonates, needed by many sea creatures to build shells and skeletons. Human-produced carbon dioxide raises the level of carbonic acid in the ocean.
Why it matters
Ocean acidification is not directly caused by climate change, but it does occur in parallel with global warming. Both phenomena are caused by increasing carbon dioxide
in the atmosphere, which is primarily the result of burning of fossil fuels (coal, gas and oil).
Many sea creatures including corals, shellfish and lobsters, need carbonate to build their protective calcium carbonate shells and skeletons. With lower levels of carbonate in the oceans, they expend more energy making shells and less energy feeding and growing. Human-produced carbon dioxide dissolving in seawater (along with the chemical reaction that removes carbonate) creates higher ocean acidity (lower pH), which in turn can dissolve shells. Scientists surmise that if sea creatures can’t produce their shells and skeletons as quickly as the acidic ocean waters dissolve them, the populations of these animals could drastically decline. Many types of plankton – the basic building block for the ocean’s food chain – also need carbonate to make protective shells. Losing these organisms would disrupt the ocean food chain.
Immediate and long-term impact Ocean acidity is harming the ability of reef-building corals to produce their protective skeletons. Researchers say that by the end of this century, coral reefs may erode faster than new coral formations can be created at many locations in the tropical oceans.
Oysters along the U.S. Pacific Coast are already having difficulty in changing from their floating larval stage to their shell-building life on the sea bottom. This is naturally affected by upwelling of deep water, which is more acidic than surface water. Surface acidification will likely exacerbate the stress on marine life. (There are likely other stressors involved, including changes in salinity, predator populations and oxygen levels.)
Tests on pteropods (tiny floating sea snails) show that under the conditions expected by the year 2100, shells will dissolve in 45 days. These pteropods are a food source for larger ocean creatures, including young salmon.
Sources: NOAA/Pacific Marine Environmental Laboratory; Mark Altabet, professor at UMass Dartmouth’s School of Marine Science and Technology, NASA, Global Wind Energy Council FRED MATAMOROS AND GABRIEL UTASI/GATEHOUSE MEDIA
Tips to help 1. Support clean energy to reduce dependence on fossil fuels.
2. Buy local and go organic. Organic farmers return carbon to the soil; buying local food reduces fossil fuels used for transportation.
3. Reduce overall energy consumption. See tips on Page 38.
An onshore wind turbine with a capacity of 2.5 MW can produce more than 6 million kWh in a year enough to supply 1,500 average EU households with electricity.
