By Madeleine Cuff , New Scientist.  Excerpt: Rivers around the world are leaking ancient carbon back into the atmosphere. The finding has taken scientists by surprise and suggests human activities are damaging the natural landscape far more than first thought. Researchers already knew rivers released carbon dioxide and methane as part of the global carbon cycle – the short-term movement of gases that happens as living things grow and decompose. They are thought to emit around 2 gigatonnes of this carbon each year. But when  Josh Dean  at the University of Bristol, UK, and his colleagues set out to determine how old this carbon really is, they found that around 60 per cent of global river emissions are from thousands-of-years-old stores. Ancient carbon is trapped in rocks, peat bogs and wetlands. The findings suggest that as much as 1 gigatonne of it is being released back into the atmosphere each year through rivers. ...The pressing question now is why rivers are releasin...

By CARINE F. BOURGEOIS et al, Science.  Abstract: Mangroves’ ability to store carbon (C) has long been recognized, but little is known about whether planted mangroves can store C as efficiently as naturally established (i.e., intact) stands and in which time frame. Through ...models compiled from 40 years of data and built from 684 planted mangrove stands worldwide, we found that biomass C stock culminated at 71 to 73% to that of intact stands ~20 years after planting. Furthermore, prioritizing mixed-species planting including  Rhizophora  spp. would maximize C accumulation within the biomass compared to monospecific planting. Despite a 25% increase in the first 5 years following planting, no notable change was observed in the soil C stocks thereafter, which remains at a constant value of 75% to that of intact soil C stock, suggesting that planting effectively prevents further C losses due to land use change. These results have strong implications for mangrove resto...

By Manuela Andreoni , The New York Times.  Excerpt: The residents of Maracaçumé, an impoverished town on the edge of the Amazon rainforest, are mystified by the company that recently bought the biggest ranch in the region. How can it possibly make money by planting trees, which executives say they’ll never cut down, on pastureland where cattle have been grazing for decades? ...The new company ...is a forest restoration business called Re.green. Its aim, along with a handful of other companies, is to create a whole new industry that can make standing trees, which store planet-warming carbon, more lucrative than the  world’s biggest driver  of deforestation: cattle ranching. ...About a fifth of the great rainforest is already gone. And scientist warn that rising global temperatures could push the entire ecosystem, a trove of biodiversity and a crucial regulator of the world’s climate, to collapse in the coming decades unless deforestation is halted and  an area the siz...

https://eos.org/research-spotlights/africas-carbon-sink-capacity-is-shrinking By Rachel Fritts , Eos/AGU.  Excerpt: The population of Africa, the second-largest continent in the world, currently sits at about 1.4 billion, but is set to exceed 2 billion by 2040. This means greater swaths of land than ever before are being used for agriculture, and livestock numbers are increasing. A new estimate of Africa’s greenhouse gas budget between 2010 and 2019 quantifies just how much these changes in land use have affected Africa’s role in the global carbon cycle. ...To make their estimates,  Ernst et al.  ...took a comprehensive look at all major potential carbon sources, including human sources such as agriculture and fossil fuel emissions and natural sources such as termites and wildfires. They also considered natural sinks: the  grasslands ,  savannas , and  forests  that still cover much of the continent. The team found that between 2010 and 2019, Africa tr...

https://www.science.org/content/article/forests-could-suck-226-gigatons-carbon-if-restored-and-protected-study-argues By RIK STOKSTAD , Science.  Excerpt: The restoration and protection of forests worldwide could help remove about 226 gigatons of carbon from the atmosphere, according to a study published today in  Nature . That’s equivalent to roughly 20 years of emissions from burning fossil fuels and other sources at current rates. Some experts say the analysis provides a more reliable estimate of the carbon-capturing potential of forests than a previous, controversial study that analyzed only the potential benefit from restoring trees to degraded land. But critics are skeptical that the new number is even remotely achievable. ...Humans have cut down a significant fraction—perhaps as much as half—of the forests that once existed. And every year, deforestation contributes 15% of all the greenhouse gas emissions caused by humans. So, scientists have been interested in finding ...

https://eos.org/research-spotlights/gently-down-the-stream-carbons-journey-from-land-to-sea-and-beyond By Nathaniel Scharping , Eos/AGU. Excerpt: Movement of carbon from land to ocean and atmosphere plays an important, but understudied, role in the global carbon cycle. Rivers, streams, lakes, and reservoirs occupy just 1% of Earth’s surface, but they provide a route for large amounts of terrestrial carbon to reach the ocean. Along the journey, carbon dioxide is also released into the atmosphere in a process known as evasion. But much about the land-to-ocean carbon cycle is not yet understood. ... Tian et al.  present a global quantification of carbon export and carbon dioxide (CO 2 ) evasion from before the industrial era to the present. Their research indicates that inland waters move nearly half of the carbon absorbed by the land to the atmosphere and oceans. It also reveals significant anthropogenic perturbations to this land-to-ocean carbon cycle. Their work is the first globa...

https://eos.org/articles/the-ocean-is-still-sucking-up-carbon-maybe-more-than-we-think By Nancy Averett , Eos/AGU.  Excerpt: Recent studies looking at carbon-sequestering microbes suggest we still have a lot to learn about the ocean’s biological carbon pump. The ocean plays a critical role in carbon sequestration. Phytoplankton, which live on the warm, light-filled surface, suck carbon dioxide out of the atmosphere for food. They also need nutrients such as phosphorus and nitrogen from colder, heavier, saltier water that  upwells  into warmer layers. When phytoplankton die, they sink, bringing some of the carbon and other nutrients they consumed with them back to the ocean depths. Key to this circular process, known as the ocean’s  biological carbon pump , is the vertical mixing of the surface and deeper water layers, which occurs through such mechanisms as currents, winds, and tides. ...traditional scientific models have long predicted that as the planet warms...

https://www.washingtonpost.com/climate-environment/2022/02/21/social-cost-of-carbon-biden By Maxine Joselow , The Washington Post.  Excerpt: A recent court ruling that bars the Biden administration from accounting for the  real-world costs of climate change  has created temporary chaos at federal agencies, upending everything from planned oil and gas lease sales to infrastructure spending. The  Feb. 11 decision  by a Louisiana federal judge blocked the Biden administration from using a higher estimate for   the damage that each additional ton of greenhouse gas pollution causes society. This formula, called   the social cost of carbon, applies to   consequential decisions affecting fossil fuel extraction on public lands, infrastructure projects and even international climate talks. ...President Biden last year directed federal agencies to applyan interim social cost of carbon of $51 per ton — the figure used under former president Barack Obama — wh...

https://eos.org/articles/large-herbivores-may-improve-an-ecosystems-carbon-persistence By  Rishika Pardikar , Eos/AGU.  Excerpt: The grazing habits of wild animals like elephants and boars enable long-term carbon storage, according to new research that stresses the need to align climate mitigation goals with biodiversity conservation.…

https://www.sciencemag.org/news/2021/04/microbes-are-siphoning-massive-amounts-carbon-earth-s-tectonic-plates Source:  By  Raleigh McElvery , Science Magazine.  Excerpt: A few kilometers below our feet lies a hidden world of microbes whose chemical reactions are shaping the long-term habitability of the planet. A new study suggests some of these microbes are siphoning off massive amounts of carbon as it enters Earth, using it to fuel their own sunless ecosystems. ...Researchers say the microbes represent an overlooked factor in efforts to balance Earth’s deep carbon cycle. ...These microbes could be  sequestering 2% to 22% of the carbon previously thought to reach the deep mantle , the researchers report today in Nature Geoscience. ...  

https://www.sciencemag.org/news/2021/03/new-generation-carbon-dioxide-traps-could-make-carbon-capture-practical Source:  By  Robert F. Service .  Excerpt: Windmills and solar panels are proliferating fast, but not fast enough to stave off the worst of climate change. Doing so, U.N. climate experts say, will also require capturing carbon dioxide (CO 2 ) from the tens of thousands of fossil fuel power plants and industrial smokestacks likely to keep belching for years to come. Today’s most popular approach for capturing CO 2  is too expensive for widespread use. But researchers are now developing a new generation of chemical CO 2  traps, including one shown this month to reduce the cost by nearly 20%. When existing U.S. tax credits are added to the mix, carbon capture is nearing commercial viability, says Joan Brennecke, a carbon capture expert at the University of Texas, Austin. ... in the March issue of International Journal of Greenhouse Gas Control, the PNN...