Reprinted with permission from Hackensack Tidelines (Summer 2018)
Marshlands Can Be Protected and Generate Revenue
Riding the train across the Meadowlands I can see the extensive marshlands, fields of tall grasses and water in the midst of the highly developed metropolitan area surrounding the lower Hackensack River. It is truly a great sight to see these marshes, which were once landfills, reclaimed and revitalized, thanks in large part to the Clean Water Act of 1972.
However, we are not in the clear when it comes to wetlands preservation and cannot be complacent. The Meadowlands’ proximity to New York City continues to exert great pressure from the business develop these open lands. For example, not long ago a single acre of undeveloped marshland in the Meadowlands had a market value of $250,000. Many projects looking to make the Meadowlands a revenue source, such as farming, diking, dumping and development, have failed.
But there is also good news. Ironically, the threat of global warming, with its excess greenhouse gases,has led to emerging carbon markets that may provide a unique opportunity for the marshlands to generate revenues just by growing wild.
There are basically five major carbon pools on earth: the atmosphere, oceans, forests, fossil fuels and soil. The greatest pool of carbon is found buried in the soil. Through deforestation and extraction, and burning of fossil fuels that power our economy, we have upset the natural balance of these carbon pools.
As a result, the concentration of CO2 in the atmosphere has now surpassed 400 ppm, which is more than a 30 percent increase from 310 ppm in 1961. We are basically taking carbon that used to be buried and putting it in the air, and unless we stop or do something to contain this increase we are headed for big trouble.
Before a young graduate student from Illinois developed an instrument to measure carbon dioxide from the atmosphere the prevailing belief was that CO2 concentrations in the atmosphere varied around the globe according to where air masses originated. This changed in the 1960s when Charles Keeling was able to demonstrate that CO2 concentration[s] in the atmosphere have strong seasonal variation but are essentially the same everywhere in our atmosphere, around 310 ppm in 1956.
In 1957, Keeling witnessed nature withdrawing CO2 from the air during the summer and returning it to the atmosphere each year. This was the first time that we recorded our planet functioning as a super organism. Keeling established the first worldwide CO2 concentration baseline that we all use today to assess global warming and climate change. In 1961, in what became known as the “Keeling Curve,” he showed unequivocally that carbon dioxide levels were rising steadily.
Almost all (97-98 percent) actively publishing climate researchers support mainstream views that the excess CO2 in the atmosphere is manmade and driving climate change. A small minority (2-3 percent) do not believe climate change is happening. Common sense would say that if you ask 10 doctors for a second opinion and 9 out of 10 tell you that you are sick, then most likely you are sick.
As good inventive Americans we would like to find a magic bullet to solve the problem of excess greenhouse gas in the atmosphere. We are looking to develop drawdown technologies that pull greenhouse gases out of the atmosphere and put them back in the soil. We are also considering geo-engineering options to tackle climate change directly by limiting the amount of sunlight reaching the planet’s surface.
However, there is little doubt in my mind that in the long term we will need to involve financial markets to regulate carbon emissions. Emitting carbon has a cost. Through a carbon credit system people who emit carbon pay for this privilege and people who bury the carbon get paid for this service.
The key to a successful carbon credit system is the credit given for carbon removed from the atmosphere that is then buried for long periods of time (greater than 100 years). A planted forest will remove carbon dioxide as it builds its biomass. But if wood is burnt when the forest is harvested, most of the to the atmosphere. In this case, the value of the carbon credit should be less, or not count at all, because of the short time period (less than 100 years) that carbon is actually removed from the atmosphere.
Up until 1997 we were not thinking about the ability of plants to remove and bury carbon from the atmosphere in the context of climate change. In fact, carbon sequestration was not even mentioned in the 1997 Kyoto protocols. We now know that tidal wetlands are some of the most effective plant communities in removing and burying carbon. Not only is the carbon sequestered by tidal wetlands buried, but in the absence of disturbances, carbon may remain buried for hundreds of years in the wetland peat.
With this new understanding, we know marshlands of the Meadowlands not only provide habitat that promotes biodiversity and protects against flooding but also provide the key ecological service of removing CO2 from the atmosphere and burying it for long periods of time in the sediments. These wetlands have been burying carbon for about 2,000 years, where it’swell stored in the 7-20 feet of peat under the marsh surface. It’s just a matter of time for a carbon market to mature and for marshlands to start generating carbon credits that can be sold in the open market.
Are we saying that wetlands are the magic bullet that will solve the problem of climate change? Not so fast. There may not be enough marshland acres on earth to cancel out our current manmade emissions. Before anything can be traded we need to know the actual sink strength of marshlands. In other words, how much carbon can 1 square meter of natural marshland bury in one year and for how long does the carbon remain buried? Having this information will be crucial for marshlands to be considered and play an effective role in the carbon credit market.
This is not a simple question to answer since not all the carbon from roots, stems and leaves that decay at the end of the growing season are buried in place in the marsh. Important amounts of carbon are lost to biological respiration in the form of carbon dioxide. There are also losses in the form of methane (CH4) and through lateral transport of stem and leaf fragments that float away with the tide.
We know that whatever carbon is buried in sediments represents the net carbon stored after all other forms of carbon have been subtracted by natural process. Measuring the remaining carbon in the soil (direct method) is the most reliable way to measure the rate of carbon burial in marshland sediments.
There are also indirect methods which use instrumentation to measure the amounts of carbon trapped by plants through photosynthesis and the carbon emissions from plants due to respiration. This alternative indirect method involves long term field measurements (multiple growing seasons) and instruments such as 3D anemometers, open path carbon dioxide sensors and data loggers that measure CO2 concentrations above the canopy up to 20 times per second (20Hz). In a perfect world the direct and indirect methods should give identical or very similar results.
Three years ago we set out to measure the carbon dioxide sink strength of New Jersey Meadowlands marshlands using both the direct and indirect methods. Our objective was to measure the carbon dioxide sink strength and carbon holding time by marshlands. In other words, to find out the amount of carbon that is sequestered by marsh plants and the amount of time this carbon remains buried after it is captured through photosynthesis.
We collected sediment samples using a Russian peat core that in some cases went down 22 feet into the peat. We dated the different depths of the cores using C14 and Cs 137 and measured carbon concentration at 5 centimeter intervals. Nearby, in a marshland near Secaucus High School, we set up an eddy covariance sampling station (indirect method) for an entire growing season that recorded the amount of carbon captured by the plants during the day and carbon respired (emitted) by the plants during the night. After three years of research we produced some solid numbers describing the amount of carbon captured and its residence time in the sediments.
Our study showed that when a marsh plant dies at the end of the growing season 78 percent of its carbon is lost to natural processes such as emissions of CO2 and CH4 or as fine plant particulates that float way with the tide. The remaining 22 percent of the carbon is buried in place. According to our study using the direct method, the extent of the burial was 191 grams of carbon per square meter of marsh per year.
The extent of the burial calculated by the indirect method was 213 grams of carbon per square meter of marsh per year. As expected, both methods arrived at similar values. Our study also showed that of the total carbon buried (i.e. ~200 grams per meter square/yr/), 78 percent remained buried after 130 years and more than 50 percent remained buried after 600 years.
One acre of marshland in the Meadowlands is able to bury about 800 kilos of carbon per acre per year and most of this carbon remains buried after 130 years. The price of a carbon credits today is not high (~ $15 a ton of C02) but it will most likely only go up. There are 5,933 acres of marshlands in the Meadowlands that in today’s carbon market would earn $71, 200 a year. It may be that for the first time we may be able to extract revenue from the marshlands not by farming, developing or dumping in them, but by just letting the marshes grow wild.
*Dr. Francisco Artigas is Director of the Meadowlands Environmental Research Institute (MERI).