Price of Coral Carbon Offsets
(To calculate the Price of Coral Carbon Offsets requires knowing how much CO2 the corals pull out of the sea water.
That was a challenge to determine, and we are still trying to nail down the figure even further.
I have been studying scientific papers that discuss coral respiration, coral photosynthesis, and utilization of carbon by corals.
If you have any additional info of suggestions, please let us know.)
Currently the price of us propagating and planting one Coral is $6.00 USD (equal to 4.60 Pounds Sterling, 5.45 Euros, or 656 Japanese Yen). We estimate that $6 yields 1.3 metric tons of CO2 offset by the time it reaches 40 years old. Keep in mind, many species of corals continue growing and expanding, some living for hundreds of years ! And there are many many factors that affect growth rate.
So the cost of one Coral Offset averages out to be $4.60 USD per metric ton of CO2 removed from the atmosphere.
Different species of coral grow at different rates depending on water temperature, salinity, turbulence, and the availability of food. The massive corals are the slowest growing species, adding between 5 and 25 millimeters (0.2–1 inch) per year to their length. Branching and staghorn corals can grow much faster, adding as much as 20 centimeters (8 inches) to their branches each year.
It is impossible to get an EXACT figure of how much CO2 corals (and trees) use up, because each species is different, each location is different, and there are so many potential limiting factors.
The best we can do is come up with an average amount.
The three biggest factors that affect photosynthesis are:
1-Light intensity and wavelength.
The higher the intensity, to an limit, in general the more photosynthesis. As you do deeper in the water, some of the shorter wavelengths are filtered out.
2-Carbon dioxide concentration. Too much can have a negative effect. The plants absorb carbon dioxide for photosynthesis through the same pores (called stomata), that they release water vapor. But when carbon dioxide levels are high, the leaf pores shrink. This causes less water to be released, diminishing the tree's cooling power.
3- Temperature. Enzymes work better in warm conditions (up to about 50ºC when enzymes start to be destroyed by heat.
The amount of algae (zooxanthellae-the symbiotic dinoflagellate that photosynthesizes) also affects the rate of photosynthesis.
Plants in lighting conditions unfavorable for photosynthesis synthesize more chlorophyll, to absorb the light required
the effects of some plant diseases affect the amount of chlorophyll, and therefore the ability of a plant to photosynthesize, such as downy mildew in grape vines.
Other factors like amount of chlorophyll, availability of micro nutrients such as Magnesium, will also affect the rate of photosynthesis,
The thing is that photosynthesis will be held back by whichever factor is in shortest supply. Its called the limiting factor.
You can calculate your approximate Carbon Footprint here.
You can purchase Coral Carbon Offsets on our Purchase CO2 Offsets Page here.
How does this compare to the price of tree offsets ?
We looked at a number of Carbon offset companies that plant trees, and their prices were all over the map. Worldwide, they range from $0.10 per tonne to $44.80 per tonne ! There are a lot of assumptions one must make in order to come up with a value.
A typical hardwood tree can absorb as much as 48 pounds of carbon dioxide per year. This means it will sequester nearly 1 ton of carbon dioxide by the time it reaches 40 years old. The current price of Carbon offsets for trees ranges from $3.05 / tree ( with a minimum purchase of 189 trees) to $10.95 per tree.
A 2016 study conducted by Forest Trends' Ecosystem Marketplace reported that the average price of a carbon offset is about $3.30 per tonne of carbon dioxide equivalent.