In this quick exhibit from Smithsonian Online, learn about Blue Carbon and its environmental functions
“What is blue carbon? It’s a term used to describe the carbon that is captured from the atmosphere by ocean ecosystems, mainly coastal mangroves,seagrasses and salt marshes. These coastal areas can hold up to five times more carbon than tropical forests, which means they play an important role in both removing excess carbon from the atmosphere and storing that carbon for the long haul. Destruction of these ecosystems releases the stored carbon, in addition to removing important wave protection and fish nursery grounds. ”
“Mangroves are tangled orchards of spindly shrubs that thrive in the interface between land and sea. They bloom in muddy soil where the water is briny and shallow, and the air muggy. Salt marshes and sea grasses also flourish in these brackish hinterlands. Worldwide, these coastal habitats are recognized for their natural beauty and ability to filter pollution, house fish nurseries and buffer shorelines against storms.
Less known is their ability to sequester vast amounts of carbon—up to five times that stored in tropical forests. Dubbed “blue carbon” because of their littoral environment, these previously undervalued coastal carbon sinks are beginning to gain attention from the climate and conservation communities.
Because they hold so much carbon, destroying them can release substantial amounts of CO2. People around the world wreck coastal habitats through aquaculture, agriculture, timber extraction and real estate development. To date, human encroachment has destroyed more than 35 percent of mangroves, 30 percent of sea grass meadows and 20 percent of salt marshes.
Stopping such destruction could therefore become an important element in confronting climate change. “Blue carbon is a source of emissions that hasn’t been addressed by the climate community and therefore creates an opportunity to reduce emissions,” says Roger Ullman, executive director of the Linden Trust for Conservation in New York City, which promotes the use of conservation finance and environmental markets. “These fabulous ecosystems…don’t cover a very large expanse of territory, yet still provide enormously important services to humanity and are being destroyed three or four times faster than the rate of tropical forests.”
Emissions from wetlands destruction
Case in point is California’s Sacramento–San Joaquin River Delta, explains Dan Laffoley, marine vice chairman of the World Commission on Protected Areas at the International Union for Conservation of Nature and Natural Resources. Over the last 100 years, 1,800 square kilometers of wetlands were drained, emitting two gigatons of CO2 that had been accruing in the plants and soils for thousands of years. Between 10 million and 15 million tons of CO2 continues to be released from the Sacramento Delta each year, an amount equivalent to around 3 percent of California’s total greenhouse gas emissions.
At the global scale, coastal wetland destruction could account for 1 to 3 percent of industrial emissions; a number that will increase along with coastal wetland destruction. “In 2011 we have a reason why mud is important,” Laffoley says.
Even so, almost all coastal and marine system research and exploration is about a decade behind its terrestrial counterpart. People have focused on understanding the surrounding lands, rather than the unseen animals, plants and processes below the ocean’s surface, explains Emily Pidgeon, director of the Marine Climate Change Program for Conservation International. The ocean is more dynamic and its systems generally more complicated to access and understand than land-based ecosystems, such as forests.
Take remote sensing, for example. Most approaches, including satellite-based systems, cannot see underwater. So whereas these methods very effectively provide data that enable scientists to estimate the amount of carbon in forests, they cannot get the equivalent information on the carbon load of sea grasses or other submerged marine ecosystems, especially in sediment where most of the CO2 in blue carbon systems is stored. Instead, scientists are required to go to sites and dig up meters of the sediment to measure how much carbon it holds—a thankless task, to be sure.
“Mangroves are as unsexy as you get, since you ride a boat through them and get covered in mosquitoes,” Pidgeon says.
Green cash for blue carbon
Getting local communities to save their mangroves will depend on economics. Land managers, farmers and other developers often opt to control these watery landscapes, thereby transforming them into income-generating acreage, such as a shrimp farm or rice paddy. The carbon markets, with their carbon credits selling between $15 to $20 per ton, could offer an alternative. The fees would encourage land conservation, which would prevent the release of carbon into the atmosphere, and the markets would reward them for mitigating climate change.
Whereas many of these programs are at least three to five years in the future, the preliminary economics looks like it could work, especially in certain cases to preserve these fragile ecosystems, such as avoiding the conversion of mangroves to shrimp farms in the Indo-Pacific region.
Still, the main hope for conserving these coastal habitats lies in a combination of economics and science. The first step is recognizing the importance of coastal carbon pools as a significant tool for climate mitigation, says Stephen Crooks, a wetlands expert who is climate change program manager of ESA PWA, a San Francisco–based environmental consulting and engineering firm.
Even without carbon markets nations have obligations to manage their greenhouse gas emissions, which means that the carbon in these coastal habitats can be tallied in national accounts as a way of contributing to their management of global greenhouse emissions. This would be especially helpful in the Coral Triangle (an oceanic area between Southeast Asia and northern Australia that encompasses Indonesia, the Philippines, Malaysia, East Timor, Papua New Guinea and the Solomon Islands) as well as Bangladesh, Indonesia and China, where coastal habitats are being destroyed at an alarming rate. Companies could also start volunteering to launch socially and environmentally friendly coastal habitat projects in the name of climate protection.
The final prong would be the creation of international carbon markets. As Crooks puts it: “One day the biggest bang for your buck may come from conservation.”
By Nell Greenfieldboyce (NPR) July 11, 2016
The way clouds cover the Earth may be changing because of global warming, according to a study published Monday that used satellite data to track cloud patterns across about two decades, starting in the 1980s.
Clouds in the mid-latitudes shifted toward the poles during that period, as the subtropical dry zones expanded and the highest cloud-tops got higher.
These changes are predicted by most climate models of global warming, even though those models disagree on a lot of other things related to clouds, says Joel Norris, a climate scientist at the University of California, San Diego.
“I guess what was surprising is that a lot of times we think of climate change as something that’s going to occur in the future,” says Norris. “This is happening right now. It’s happened during my lifetime — it was a bit startling.”
About 70 percent of our planet is covered by clouds, at any given moment. These constantly moving shape-shifters aren’t exactly easy for scientists to study.
Clouds aren’t as simple as their fluffy nature might suggest. To understand them, scientists have to track the behavior of tiny water droplets, as well as huge masses of clouds that might be hundreds of miles wide.
And climate modelers also have to take into account the fact that clouds can have two different effects on temperatures.
“During daytime, if there are a lot of clouds present, thick clouds, then that will keep the temperature cooler,” says Norris, because clouds reflect incoming sunlight back to space.
But thick clouds can also act like a blanket that keeps the Earth’s warmth in, he says, “which is the reason why a cloudy night won’t be as cold at the surface as a clear night.”
Clouds have been called the wild card of climate science. Researchers argue over how exactly global warming will affect clouds and vice versa.
While weather satellites can give you tons of cloud pictures, Norris says these satellites aren’t that great for trying to figure out long-term trends.
“The difficulties we have is that every few years a new satellite is put up with a different instrument, the orbits change, and this all changes how much cloud the satellite measures,” Norris explains.
So he and his colleagues recently did a bunch of corrections that would make it possible to compare cloud measurements over a couple of decades, starting in the 1980s.
In this week’s issue of the journal Nature, the researchers explain how their findings match what scientists would expect to see, based on climate models.
Norris says it’s probably happening primarily because of two influences — human-produced global warming, and also the recovery from the cooling effect of two volcanic eruptions during that time frame.
So will other climate researchers buy this new history of clouds? Kevin Trenberth at the National Center for Atmospheric Research in Colorado isn’t so sure.
“This is a very good attempt to try and get a handle on this, but I don’t think it’s the final answer,” says Trenberth, who notes that the time frame studied was pretty short and included a period often described as the global warming hiatus, from 1999 to 2013.
Climate researchers still have a lot of work to do when it comes to understanding clouds, says Trenberth, who believes the state of the science is still like that old Joni Mitchell song Both Sides Now, in which she sings, “I really don’t know clouds at all.”
by AMNH on
A series of papers recently published by scientists at the American Museum of Natural History suggests that polar bears in the warming Arctic are turning to alternate food sources. As Arctic sea ice melts earlier and freezes later each year, polar bears have a limited amount of time to hunt their historically preferred prey—ringed seal pups—and must spend more time on land.
The new research indicates that at least some polar bears in the western Hudson Bay population are using flexible foraging strategies while on land, such as prey-switching and eating a mixed diet of plants and animals, as they survive in their rapidly changing environment.
“There is little doubt that polar bears are very susceptible as global climate change continues to drastically alter the landscape of the northern polar regions,” said Robert Rockwell,a research associate in the Museum’s Department of Ornithology. “But we’re finding that they might be more resilient than is commonly thought.”
Polar bears are listed as a threatened species under the United States Endangered Species Act and are classified as “vulnerable” with declining populations on the International Union for Conservation of Nature and Natural Resources’ Red List. Climate warming is reducing the availability of their ice habitat, especially in the spring when polar bears gain most of their annual fat reserves by consuming seal pups before coming ashore for the summer. The new work, led by Rockwell and Linda Gormezano, a postdoctoral researcher in the Museum’sDivision of Vertebrate Zoology, examines how polar bears might compensate for energy deficits from decreasing seal-hunting opportunities.
In the first paper, published in spring 2013 in the journal Polar Ecology, the researchers provide, for the first time, data and video of polar bears pursuing, catching, and eating adult and juvenile lesser snow geese during mid-to-late summer, when the geese are replacing their primary flight feathers.
In the second paper, published in summer 2013 in the journalEcology and Evolution, researchers used polar bear scat to show that the diet of at least some of the bears has shifted from what it was 40 years ago, before climate change was affecting the Hudson Bay lowlands. Today’s polar bears are preying more on caribou as well as on snow geese and their eggs.
In the final paper in the series, published in December 2013 in the journal BMC Ecology, the researchers show that polar bears are, with a few exceptions, consuming a mixed diet of plants and animals. The predominance of local vegetation in collected scat suggests little movement among habitat types between feeding sessions, indicating that the polar bears are keeping energy expenditure down.
Taken together, the research indicates that during the ice-free period, polar bears are exhibiting flexible foraging behavior. This behavior likely derives from a shared genetic heritage with brown bears, from which polar bears separated about 600,000 years ago.
For more details, see the Museum’s press release.
Posted by Robert Schubert, FAS Office of Capacity Building and Development, on June 27, 2016
Pablo Chacón, a young Guatemalan farmer who is studying agroforestry at the Tropical Agricultural Research and Higher Education Center (CATIE) in Turrialba, Costa Rica, can now show the people in his home community how livestock grazing and hardwood forests can co-exist and prosper. Earlier this month, he told me and other Foreign Agricultural Service (FAS) visitors to CATIE that the education he gained from his FAS-funded scholarship to CATIE has equipped him to be a change maker.
“CATIE’s research in the tropics shows that degraded lands can be restored using combined forest and pastoral production systems,” Chacón said. “The benefits of trees in pastures are clear: The shade helps reduce stress in animals during the dry season, keeps moisture in the soil and retains the strength of pastures during the dry season.”
Indeed, through his studies at CATIE, Chacón learned that his family and other in his highland community not only can, but should, grow trees in pasture fields. The trees provide shade for the cows on hot days and also help fight erosion. Helping this young Guatemalan become an agent of positive agricultural change exemplifies the capacity-building programs that FAS executes throughout Latin America, particularly in Central America.
With a capacity built up over more than 100 years, the U.S. agricultural sector is, arguably, the most efficient in the world. It profits greatly from food and feed exports, including to Central America, where governments expressed the desire to recreate U.S. agricultural efficiency. The United States agreed to train farmers, processors and government policymakers to build stronger agricultural systems within their countries. We have made good on our word, and the technical assistance has been a win-win for our economies. For nearly a dozen years, since the CAFTA-DR trade agreement entered into force, USDA has been training Central American farmers to grow more food in ways that raise farmer incomes, minimize waste, reduce pests and safeguard the environment.
Pedro Chacón’s story is just one example of how USDA promotes agricultural practices that help small farmers in developing countries produce food more efficiently and sustainably. But how does this benefit the United States?
First, more efficient farming methods generate more income for farmers, who can then participate in the global economy. Second, all farmers use precious resources: The finite amount of arable land and water on Earth, combined with the challenge of feeding 9.6 billion people by 2050, will require farmers everywhere to be good stewards of our natural resources. Finally, the U.S. food and beverage industry, a thriving part of our economy, needs commodities – namely cocoa and coffee – that are not grown commercially in the United States. For every dollar of cocoa the U.S. imports, our own farmers sell another $2-4 of dairy, sugar and peanuts. And there are more than 130 million coffee drinkers in the United States. Central America is a main source of both cocoa and coffee, so USDA’s assistance in protecting the production of these commodities is also protecting a major driver of our domestic economy.