More than a thousand low-lying tropical islands risk becoming “uninhabitable” by the middle of the century — or possibly sooner — because of rising sea levels, upending the populations of some island nations and endangering key U.S. military assets, according to new research published Wednesday.
….The threats to the islands are twofold. In the long term, the rising seas threaten to inundate the islands entirely. More immediately, as seas rise, the islands will more frequently deal with large waves that crash farther onto the shore, contaminating their drinkable water supplies with ocean saltwater, according to the research.
The islands face climate-change-driven threats to their water supplies “in the very near future,” according to the study, published in the journal Science Advances.
….The U.S. military supported the research in part to learn about the vulnerability of its tropical-island installations. The Pentagon base on Roi-Namur and surrounding islands supports about 1,250 American civilians, contractors and military personnel.
….The research was commissioned by the Pentagon’s Strategic Environmental Research and Development Program and published in a more lengthy form earlier this year, in a report that partly focused on helping the military identify sites where its assets could be vulnerable….
What happens to your land after fire, and what should a concerned property owner do in its aftermath?
The CA Native Plant Society Fire Recovery Guide addresses those questions in an easy-to-use booklet, created in response to the widespread Wine Country fires. The Guide is a collaborative effort between CNPS, North Bay partner organizations, and some of the best fire experts in the state. Sections include:
Frequently Asked Questions
Dos and Don’ts
Care and Recovery
Helpful decision trees, and more
While this Guide is designed to serve landowners in the North Bay, our hope is that others will take this material and expand and adapt it to benefit others in need elsewhere in California, today and tomorrow.
Not only is the Guide meant to provide best-practice instructions and resources, we also hope it will encourage conversations about how we can live with fire in an increasingly fire-prone state, while also ensuring there is a place for the beautiful plants and incredible wildlife that make living in California so special.
Underwater grasses that provide vital places for fish and crabs to live and hide from predators covered more than 100,000 acres of the Chesapeake Bay in 2017 — the most ever recorded in a 34-year aerial survey, scientists said Tuesday.
The Virginia Institute of Marine Science found 104,843 acres of grasses across the estuary, the first time since it began its survey in 1984 that vegetative coverage surpassed the 100,000-acre threshold.
It was a third straight year that grass acreage grew, gaining by 5 percent from 2016 to 2017.
The Patapsco River was among the areas with the strongest grass growth. Acreage jumped more than three times, from 3 acres in 2016 to 14 acres in 2017.
Officials with the Chesapeake Bay Program, the federal office that released the data, said the survey results show that its work with bay watershed states to limit pollution is working. The federal-state partnership adopted a “blueprint” in 2010 to reverse decades of environmental degradation and restore the bay’s health by 2025.
The Annapolis-based bay program has faced proposals of cuts from President Donald J. Trump’s administration, but Congress has spared its $73 million budget.
“This achievement is a true example of the power a partnership can have and I call upon all of our partners to continue their efforts toward this remarkable recovery,” said Jim Edward, the program’s acting director…..
Forest thinning could increase water flow from Sierra Nevada watersheds by as much as 10 percent.
The U.S. Forest Service says that 6 to 8 of the 21-million acres it manages in California need immediate restoration. Another 58 million acres nationally also require restoration. For California alone, restoration costs are estimated at $5 to $10 billion. But, according to the study authors, the restoration might help pay for itself.
There are too many trees in Sierra Nevada forests, say scientists. That may come as a surprise to those who see dense, verdant forests as signs of a healthy environment. After all, green is good, right? Not necessarily. When it comes to the number of trees in California forests, bigger isn’t always better….
That’s in part because trees use lots of water to carry out basic biological tasks. In addition, they act as forest steam stacks, raking up water stored in the ground and expelling it as vapor into the atmosphere, where it’s accessible to humans and forest ecosystems only when it falls back to Earth as rain and snow.
That process — by which plants emit water through tiny pores in their leaves — is known as evapotranspiration. And according to researchers, excessive evapotranspiration may harm a fragile California water system, especially during prolonged, warm droughts.
New research published this week in the journal Ecohydrology shows that water loss from evapotranspiration has decreased significantly over the past three decades. That’s due in large part to wildfire-driven forest thinning — a finding with important implications for forest and water management.
A century of forest management had kept wildfires to a minimum. But without fire, Sierra forests grew very dense. In recent decades, new policies have allowed nature to take its course, with wildfires helping to thin out overgrown forests.
….It’s Earth Week, and we are joining a campaign to share stories of #EarthOptimism. I am sharing some of those optimistic stories here. You can also follow the #EarthOptimism hashtag on Twitter for more hope and inspiration, from Cool Green Science writers, Nature Conservancy Chief Scientist Hugh Possingham (@HugePossum) and many others.
A common thread in many of these stories is that people kept working even when it looked like hope was lost. Keep working, stay optimistic and enjoy your world. It’s what will shape a better future for people and nature.
Saving Red-Cockaded Woodpeckers Through Science and Ingenuity….
Coastal Wetlands Saved $625 Million During Hurricane Sandy…
After 250 Years of Dams, A River Restored for Migratory Fish…
Citizen Science Is Growing…
Fighting Fire with Native Plants…
Seaweed Farming: A Gateway To Conservation and Empowerment…
Agriculture could pull carbon out of the air and into the soil — but it would mean a whole new way of thinking about how to tend the land.
The I.P.C.C. is preparing a special report on climate change and land use, to be finalized in 2019, that will consider in greater detail the potential of sequestering carbon in soil.
The biggest international effort to promote carbon farming is a French-led initiative called “four per 1,000″ to increase the amount of carbon in the soil of crop- and rangelands by 0.4 percent per year through agroforestry (growing trees and crops together increases carbon retention), no-till agriculture (plowing causes erosion and carbon loss) and keeping farmland covered (bare dirt bleeds carbon) among other actions. Doing so, the French argue, could completely halt the buildup of atmospheric carbon dioxide.
By 2050, California aims to reduce greenhouse-gas emissions to 20 percent of what they were in 1990. Nearly half its 58 counties have farmers and ranchers at various stages of developing and implementing carbon-farming plans.
…Climate change often evokes images of smokestacks, and for good reason: The single largest source of carbon emissions related to human activity is heat and power generation, which accounts for about one-quarter of the carbon we put into the atmosphere. Often overlooked, though, is how we use land, which contributes almost as much. The erosion and degradation of soil caused by plowing, intense grazing and clear-cutting has played a significant role in the atmospheric accumulation of heat-trapping gases. The process is an ancient one. Ice cores from Greenland, which contain air samples trapped thousands of years ago, reveal increases in greenhouse gases that correspond with the rise of farming in Mesopotamia.
Since the start of the Industrial Revolution, agricultural practices and animal husbandry have released an estimated 135 gigatons — 135 billion metric tons — of carbon into the atmosphere, according to Rattan Lal, a soil scientist at Ohio State University. Even at current rates, that’s more than a decade’s worth of carbon dioxide emissions from all human sources. The world is warming not only because fossil fuels are being burned, but also because soils, forests and wetlands are being ravaged.
In recent years, some scientists have begun to ask whether we can put some of that carbon back into the soil and into living ecosystems, like grasslands and forests. This notion, known as carbon farming, has gained traction as it becomes clear that simply reducing emissions will not sufficiently limit global warming. According to the 2014 report by the Intergovernmental Panel on Climate Change, an authority on climate science that operates under the auspices of the United Nations, humankind also needs to remove some of the carbon already in the atmosphere to avoid, say, the collapse of polar glaciers and the inundation of coastal cities worldwide. “We can’t just reduce emissions,” Keith Paustian, a soil scientist at Colorado State University and an author of an earlier I.P.C.C. report, told me. “It’s all hands on deck. Things like soil and land use — everything is important.”…
…Nearly all the carbon that enters the biosphere is captured during photosynthesis, and as it moves through life’s web, every organism takes a cut for its own energy needs, releasing carbon dioxide as exhaust. This circular voyage is the short-term carbon cycle. Carbon farming seeks to interfere with this cycle, slowing the release of carbon back into the atmosphere. The practice is often conceptualized and discussed in terms of storing carbon, but really the idea is to change the flow of carbon so that, for a time at least, the carbon leaving a given ecosystem is less than the carbon entering it.
Dozens of land-management practices are thought to achieve this feat. Planting or restoring forests, for one: Trees lock up carbon in woody material. Another is adding biochar, a charcoal made from heated organic material, directly to soil. Or restoring certain wetlands that have an immense capacity to hold carbon. (Coal beds are the fossilized remains of ancient marshes and peatlands.)
More than one-third of earth’s ice-free surface is devoted to agriculture, meaning that much of it is already managed intensively. Carbon farming’s fundamental conceit is that if we change how we treat this land, we could turn huge areas of the earth’s surface into a carbon sponge. Instead of relying solely on technology to remove greenhouse gases from the air, we could harness an ancient and natural process, photosynthesis, to pump carbon into what’s called the pedosphere, the thin skin of living soil at the earth’s surface. If adopted widely enough, such practices could, in theory, begin to remove billions of tons of carbon dioxide from the atmosphere, nudging us toward a less perilous climate trajectory than our current one….
…The I.P.C.C. is preparing a special report on climate change and land use, to be finalized in 2019, that will consider in greater detail the potential of sequestering carbon in soil. But for now the biggest international effort to promote carbon farming is a French-led initiative called “four per 1,000.” The proposal aims to increase the amount of carbon in the soil of crop- and rangelands by 0.4 percent per year through a variety of agricultural and forestry practices. These include agroforestry (growing trees and crops together increases carbon retention), no-till agriculture (plowing causes erosion and carbon loss) and keeping farmland covered (bare dirt bleeds carbon). Doing so, the French argue, could completely halt the buildup of atmospheric carbon dioxide.
….But it is California, already in the vanguard on climate-mitigation efforts, that has led the way on carbon farming. By 2050, the state aims to reduce greenhouse-gas emissions to 20 percent of what they were in 1990. Nearly half its 58 counties have farmers and ranchers at various stages of developing and implementing carbon-farming plans. San Francisco, which already has the largest urban composting program in the country, hopes to become a model carbon-farming metropolis. Cities don’t have much room to plant trees or undertake other practices that remove carbon from the atmosphere, says Deborah Raphael, the director of San Francisco’s Department of the Environment. But they can certainly produce plenty of compost. “If we can show other cities how doable it is to get green waste out of landfills, we can prove the concept,” Raphael told me. “We like to say that San Francisco rehearses the future.”
Many of California’s carbon-farming efforts owe a debt to Wick, Creque and Silver. In 2008, they founded the Marin Carbon Project, a consortium of ranchers, scientists and land managers. The goal is to develop science-based carbon-farming practices and to help establish the incentives needed to encourage California farmers to adopt them. Silver continues to publish her findings in respected journals. Creque also started a nonprofit, the Carbon Cycle Institute, that assists farmers and ranchers in making carbon-farming plans.
A new article finds that the enormous trends toward population stabilization, poverty alleviation, and urbanization are rewriting the future of biodiversity conservation in the 21st century, offering new hope for the world’s wildlife and wild places…
…Most people think that the population of people on Earth will always rise, but these authors point out that the demographic transition is already well underway. The rate of growth in global population has been dropping since the 1960s. They cite new demographic research that suggests the world population in 2100 could be as high as 12 billion or as low as 7 billion, fewer people than are alive today. The difference depends on actions we take today.Good urbanization is key. Cities lead people to choose to have smaller families, and the increased income urbanites derive from working in town mean that people can choose to conserve nature, not destroy it, through choices about what they buy and how they live.
These considerations lead the authors to suggest that within our generation, or the generation to follow, if society makes the right moves now, there could be possibilities for rewilding unimaginable to previous generations of conservationists.
They call their thinking “From Bottleneck to Breakthrough.” Recognition of the massive demographic, economic and urbanization trends suggest that conservation will best succeed if we protect the world’s threatened wildlife and wild places through the bottleneck; create safe, attractive, sustainable cities; encourage better consumer choices by costing in the environmental benefits or harms of different resources and pollutants; and by inspiring all people and all institutions of the world to care for, rather than destroy, the natural bases of life on Earth.
Eric W. Sanderson, Joseph Walston, John G. Robinson. From Bottleneck to Breakthrough: Urbanization and the Future of Biodiversity Conservation. BioScience, 2018; DOI: 10.1093/biosci/biy039
Glacial meltwater makes the ocean’s surface layer less salty and more buoyant, preventing deep mixing in winter and allowing warm water at depth to retain its heat and further melt glaciers from below.
A further increase in the supply of glacial meltwater to the waters around the Antarctic shelf may trigger a transition from a cold regime to a warm regime, characterised by high rates of melting from the base of ice shelves and reduced formation of cold bottom waters that support ocean uptake of atmospheric heat and carbon dioxide.
A new study has revealed a previously undocumented process where melting glacial ice sheets change the ocean in a way that further accelerates the rate of ice melt and sea level rise. The research found that glacial meltwater makes the ocean’s surface layer less salty and more buoyant, preventing deep mixing in winter and allowing warm water at depth to retain its heat and further melt glaciers from below.
….”This process is similar to what happens when you put oil and water in a container, with the oil floating on top because it’s lighter and less dense,” Mr Silvano said. “The same happens near Antarctica with fresh glacial meltwater, which stays above the warmer and saltier ocean water, insulating the warm water from the cold Antarctic atmosphere and allowing it to cause further glacial melting.
“We found that in this way increased glacial meltwater can cause a positive feedback, driving further melt of ice shelves and hence an increase in sea level rise.” The study found that fresh meltwater also reduces the formation and sinking of dense water in some regions around Antarctica, slowing ocean circulation which takes up and stores heat and carbon dioxide. “The cold glacial meltwaters flowing from the Antarctic cause a slowing of the currents which enable the ocean to draw down carbon dioxide and heat from the atmosphere.
“In combination, the two processes we identified feed off each other to further accelerate climate change.”…
Alessandro Silvano, Stephen Rich Rintoul, Beatriz Peña-Molino, William Richard Hobbs, Esmee van Wijk, Shigeru Aoki, Takeshi Tamura, Guy Darvall Williams. Freshening by glacial meltwater enhances melting of ice shelves and reduces formation of Antarctic Bottom Water. Science Advances, 2018; 4 (4): eaap9467 DOI: 10.1126/sciadv.aap9467
….In the rhizosphere, plants make a variety of chemical compounds called exudates. Hallett and fellow researchers at the University of Aberdeen look at the effects that exudates have on the plant and surrounding soil community. Their unique work takes small-scale measurements near the surface of the roots. The properties here can be very different from the rest of the soil.
“Roots continuously secrete chemicals into the soil as a way to liberate nutrients that are attached to soil particles,” says Hallett. In human digestion, the stomach secretes gastric juices to help break up food; exudates are the plant equivalent of gastric juices.
Hallett describes exudates’ chemical composition as “a veritable cocktail or ‘buffet’ of resources for anything in the rhizosphere.” In addition to helping plants procure nutrients, exudates are food sources for the microbes that are an important part of the soil microbiome.
Exudates also have an important role in holding soil together. Roots and fungi that live in the soil hold together larger clumps of soil, but exudates work on the micro level. Like glue, they hold together soil particles in important mechanical networks. Soil scientists call these soil networks aggregates.
…Research such as Hallett’s shows that during the growing season-and beyond-there are delicate interactions between each plant and the surrounding soil. All of these interactions affect the amount of water that is captured by soil and absorbed by plants. Production of exudates also affects how well the plants can pull vital nutrients out of the soil, and even affects the soil in the rhizosphere.
M. Naveed, L.K. Brown, A.C. Raffan, T.S. George, A.G. Bengough, T. Roose, I. Sinclair, N. Koebernick, L. Cooper, P.D. Hallett. Rhizosphere-Scale Quantification of Hydraulic and Mechanical Properties of Soil Impacted by Root and Seed Exudates. Vadose Zone Journal, 2018; 17 (1): 0 DOI: 10.2136/vzj2017.04.0083