And Now Add Climate Change to Louisiana’s Sinking Coasts
by Sarah Spiegler -- June 27th, 2011
Climate change is going to result in even more challenges for the already overburdened state of Louisiana.
At the “Our Wetlands, Our Future” Symposium in New Orleans earlier this month, a speaker described global warming and sea-level rise as the “elephant in the room” that no one wants to talk about in Louisiana.
We know that wetlands are important because they act as a sponge and filter pollution, buffer shores and cities against the impact of hurricanes, and also act as habitat for a wide range of species. But what else do they do?
Blue carbon is the idea that ocean and coastal ecosystems can absorb and trap CO2, and are a vital resource in the challenge of climate change. In Scientific American, Robynne Boyd notes:“Mangroves, salt marshes and sea grasses soak up to five times more carbon than tropical forests, making their conservation critical.” Boyd also notes that “To date, human encroachment has destroyed more than 35 percent of mangroves, 30 percent of sea grass meadows and 20 percent of salt marshes.”
Further, these types of ecosystems are being destroyed faster than rainforests, possibly up to 3 or 4 times faster. Down here in Louisiana, the constant refrain we hear is that the equivalent of one football field of their wetlands is lost every 30-38 minutes.
However, research into these ecosystems and the connection to climate processes lags behind terrestrial research. Studying the ocean is challenging because it is generally more dynamic and can be harder to research than forest ecosystems. For example, remote sensing can be used to measure carbon levels in forests, but satellites can not see underwater to measure the amount of carbon present in ocean ecosystems.
Good news is that climate and conservation scientists are now starting to more fully consider the critical roles these habitats play in climate change.
Blue Carbon Initiative
The emerging blue carbon initiative, which involves capturing and storing CO2 in coastal and ocean environments, has wetland restoration as a focal point. This is because restoring wetlands can also sequestercarbon at the same time.
In California, the CO2 trading market is planned to open in 2012, and some scientists are urging the inclusion of wetland restoration and preservation in the market. On Jan 1, 2012, California will enact a cap-and-trade law requiring 600 major industrial plants to limit greenhouse gas emissions. It will be the first carbon market in the US, and seeks to reduce greenhouse gas emissions by 15% to 1990 levels, with up to 8% of reductions allowed to come from purchasing offsets. Experts are also calling for wetland services in the already existing carbonmarkets in Europe.
There are some challenges involved in restoring wetlands: freshwater tidal wetlands can release a lot of methane, which is also a greenhouse gas. However, peat wetlands capture a large amount of CO2, so there is usually a net benefit when restoring these types of wetlands. Saltwater marshes are also good greenhouse gas sinks because salt water inhibits methane production.
Restoration Fun: Grand Isle, Louisiana
Over the past few weeks our group has participated in a number of coastal restoration activities on the barrier island, Grand Isle in southern Louisiana.
**(Another reminder that Louisiana is sinking: telephone poles on the side of the road submerged in water instead of on dry land as we drove into Grand Isle).**
We have constructed sand fences with the Barataria Terrebonne National Estuary Program.
See Becca’s video from the mangrove planting on the DukeEngage blog.