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The warmer, greener Arctic and greenhouse gas

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About 15% of the Northern Hemisphere is covered by permafrost.  Permafrost is soil and sediment that has remained frozen for long periods of time, in some cases as much as 700,000 years.  It contains large amounts of dead biomass that has accumulated over millennia and hasn’t fully decomposed.  Therefore, permafrost is an immense carbon sink.

The Arctic is warming four times faster than the rest of the planet and, as a result, thawing permafrost is becoming a carbon source.  As warming continues, ice is melting, and vegetation is spreading.    A new study, published in Nature Climate Change, looked at the state of the Arctic and boreal north from the period 1990 until 2020.  The study found that although half of the Arctic region has been growing greener, only 12% of those green areas are actually taking up more carbon.  For one thing, the growth of forests means that there is more fuel for wildfires which are increasingly common.

A study of lakes in West Greenland found that thousands of crystal blue lakes have turned brown during record heat spells.  Runoff from melting permafrost made the lakes opaque killing off plankton that absorb carbon dioxide.  Meanwhile, plankton that release carbon dioxide multiplied.  So, these lakes went from being carbon sinks to being carbon sources.

As the northern latitudes warm, ice and permafrost are melting, vegetation is spreading, and the region is becoming a source of heat-trapping gas after having been a place where carbon has been locked away for thousands of years.  According to the Nature Climate Change study, roughly 40% of the Arctic is now a source of carbon dioxide.

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Warmer, Greener Arctic Becoming a Source of Heat-Trapping Gas

Photo, posted October 14, 2024, courtesy of Christoph Strässler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting The Amazon Rainforest | Earth Wise

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The Amazon rainforest absorbs one-fourth of all the carbon dioxide absorbed by the land of the Earth.  It is by far the world’s largest rainforest, bigger than the next two largest – in the Congo Basin and Indonesia – combined.  Nearly two-thirds of it is found in Brazil but the more than 2 million square miles of rainforest includes portions in 8 countries.

The amount of carbon dioxide absorbed by the Amazon rainforest is 30% less today than it was in the 1990s as a result of deforestation, to a great extent driven by cattle ranching as well as other agricultural activities.

In early August, the leaders of the eight countries that are home to the Amazon River basin agreed to work together to conserve the rainforest.  The agreement, called the Belém Declaration, provides a roadmap to stave off the rampant deforestation. 

The agreement provides coordination between the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela to establish law enforcement to combat illegal mining and logging as well as to pool development funds for conservation and sustainable employment.  Despite the unity portrayed at the meeting, many of the governments in South America are in a precarious position because of various economic and political struggles

Apart from its critical climate impact, the Amazon rainforest is a haven for biodiversity and further deforestation would be disastrous for tens of thousands of species and could transform it into a net emitter rather than absorber of greenhouse gases.  Some parts of the region have already reached that point.

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Amazon Countries, Led by Brazil, Sign a Rainforest Pact

Photo, posted October 17, 2016, courtesy of Yeoboya via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Reducing Cattle-Driven Deforestation | Earth Wise

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The Amazon rainforest is the biggest rainforest in the world, larger than the next two biggest combined.  It covers more than three million square miles, roughly the size of the lower 48 states.  The Amazon functions as a critical sink for carbon in the atmosphere.

However, human activity has removed more than 10% of the vegetation from the Amazon rainforest since the 1960s.  Cattle ranching accounts for roughly 70% of Amazon deforestation – much of which is illegal.   

According to a study recently published in the journal Global Environmental Change, companies’ ‘zero-deforestation’ commitments could reduce cattle-driven deforestation in the Brazilian Amazon by 50%.   Better adoption and implementation of company supply chain policies for Brazilian beef and leather could significantly reduce carbon emissions. 

Between 2010 and 2018, some of the world’s largest slaughterhouses reduced cattle-driven deforestation by 15% through their commitment to zero-deforestation policies.  If these policies were fully implemented and adopted across all cattle companies operating in the Amazon, more than 9,200 square miles of forest could have been spared over the same time period, effectively halving the cattle-driven deforestation in Brazil.  

Zero-deforestation commitments currently cover 82% of beef exported from the Brazilian Amazon for trade internationally.  However, a large amount of beef production destined for Brazil’s domestic markets is not covered.

The researchers say a mix of interventions by both the private and public sector is needed to improve cattle-rearing practices and help reduce deforestation in countries like Brazil.

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Companies’ zero-deforestation commitments have potential to halve cattle-driven deforestation in Brazilian Amazon

Photo, posted January 17, 2011, courtesy of Kelly Sato via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Storage In Harvested Wood | Earth Wise

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Trees are an exceedingly important carbon sink on our planet.  For this reason, deforestation is a major contributor to climate change.  But when trees are harvested for wood products like lumber, much of the carbon in that wood continues to be stored.  Even when a wood product is discarded at the end of its useful life, it can keep storing carbon.

Over 90% of new single-family homes in the U.S. are built with wood.  Each year, about 400,000 homes, apartment buildings, and other housing units are lost to floods and other natural disasters.  Others fall apart from decay or are torn down to be replaced with newer structures.  Given how much carbon is stored in houses, it is important to understand what the future trajectory of residential structures will be.

A new study by the USDA Forest Service published in the journal PLOS ONE looks at the future of harvested wood products in residential structures.  According to the study, wood products in these structures will continue to increase the country’s carbon storage for the next 50 years. 

Even after residential structures reach the end of their useful life and much of the materials end up in landfills (which is typical in this country), the wood products do not immediately release their carbon.  It may take decades for that to happen.

The study looked at various scenarios for future home construction.  Although housing starts are projected to decline in the future, residential housing and the need to maintain existing structures are projected to continue to increase carbon storage in wood products for the next several decades.

The role of trees as a carbon sink does not end when they are harvested for their wood.

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Carbon Storage in Harvested Wood Products

Photo, posted January 27, 2022, courtesy of Luke McKernan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Record Levels Of Deforestation In The Amazon | Earth Wise

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The Amazon rainforest is the largest rainforest in the world, covering more than 2.5 million square miles.  It’s home to 10% of all known species in the world.  The Amazon rainforest’s biodiversity is so rich that scientists are still discovering new plant and animal species today.  

The Amazon rainforest absorbs huge amounts of carbon dioxide from Earth’s atmosphere, making it a key part of mitigating climate change.  The vast rainforest acts as what’s known as a carbon sink.  Simply put, a carbon sink is anything that absorbs more carbon from the atmosphere than it releases.  But as trees in the Amazon disappear, so does the ability of the rainforest to absorb carbon dioxide.

Deforestation of the Amazon rainforest remains a major problem.  According to satellite data from the Brazilian government, the number of trees cut down in the Brazilian Amazon in January far exceeded deforestation figures for the same month last year.  Approximately 166 square miles of land was deforested in January alone, which is five times greater than what was lost in January, 2021.

Cattle ranching – both for beef and for leather – remains the leading cause of deforestation in the Amazon rainforest.  Trees in the Amazon are also cut down for their wood, as well as to clear the land in order to grow food crops, such as soy, sugar, and oil palm. 

Many companies have pledged to achieve “net zero” deforestation in their supply chains over the years, but most have not lived up to the commitment. 

Deforestation is not only a major driver of climate change, but it’s also the leading cause of species extinction.  Preserving the Amazon rainforest is vital. 

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Amazon deforestation: Record high destruction of trees in January

Greenpeace calls on fast food giants to take a stand against Bolsonaro’s Amazon destruction

Hundreds of Companies Promised to Help Save Forests. Did They?

Photo, posted July 14, 2018, courtesy of Alexander Gerst via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forests And Climate Change | Earth Wise

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A carbon sink is anything that absorbs more carbon from the atmosphere than it releases.  Examples of carbon sinks include the ocean, soil, and plants.  In contrast, a carbon source is anything that releases more carbon into the atmosphere than it absorbs.  Volcanic eruptions and burning fossil fuels are two examples.

Forests are among the most important carbon sinks.  Trees remove carbon from the air and store it in their trunks, branches, and leaves, and transfer some of it into the soil.  But in many regions, deforestation, forest degradation, and the impacts of climate change are weakening these carbon sinks. As a result, some climate activists advocate for large-scale tree-planting campaigns as a way to remove heat-trapping CO2 from the atmosphere and help mitigate climate change. 

But according to a new study recently published in the journal Science, planting new trees as a substitute for the direct reduction of greenhouse gas emissions could be a pipe dream.  While planting trees is easy, inexpensive, and can help slow climate warming, the ongoing warming would be simultaneously causing the loss of other trees.  Instead, the research team says it makes more sense to focus on keeping existing forests healthy so they can continue to act as carbon sinks, and to reduce emissions as much as possible and as quickly as possible.        

But keeping forests healthy will require a paradigm shift in forest management.  Instead of trying to maintain forests as they were in the 20th century, the research team says forests need to be managed proactively for the changes that can be anticipated. 

One thing is clear: We cannot plant our way out of the climate crisis.

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Forests and climate change: ‘We can’t plant our way out of the climate crisis’

Photo, posted August 9, 2015, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Seagrasses And Ocean Acidification | Earth Wise

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Seagrasses are the basis of important marine ecosystems.   Sea turtles, bat rays, leopard sharks, fish, and harbor seals are just some of the marine creatures that visit seagrass ecosystems for the food and habitat they provide.  They are nursery grounds for many aquatic animals and many birds visit seagrass meadows to dine on what lives within them.  They may seem like slimy grasses that we walk through along some shorelines, but they are important.

These marine forests are valuable for many different reasons including climate mitigation and erosion control.  A third of the carbon dioxide emitted across the globe is absorbed by the ocean and seagrass meadows are an important carbon sink.

A new study, recently published in the journal Global Change Biology, investigated how seagrasses can buffer ocean acidification.  The six-year-long study found that these ecosystems can alleviate low ocean pH – that is, more acidic – conditions for extended periods of time, even at night in the absence of photosynthesis. 

In some places, the pH buffering from the seagrasses brings the local environments back to preindustrial pH conditions, like what the ocean might have experienced around the year 1750.

Seagrasses naturally absorb carbon as they photosynthesize when the sun is out, which drives the buffering ability.  The study found the surprising result that the effects of pH buffering even persisted during the night, when there is no photosynthesis.

The study has implications for aquaculture management as well as climate change mitigation, and conservation and restoration efforts.  Globally, seagrass ecosystems are in decline.  These results show how important it is to help them survive and prosper.

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Seagrasses Turn Back the Clock on Ocean Acidification

Photo, posted October 13, 2010, courtesy of Claire Fackler, CINMS, NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Deforestation In The Amazon Rainforest

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The Amazon rainforest is the biggest in the world.  In fact, it’s larger than the next two rainforests combined.  The Amazon rainforest covers more than three million square miles, roughly the size of the lower 48 states.  It functions as a critical sink for carbon in the atmosphere, and is home to 10% of all known species in the world.  The region’s biodiversity is so rich that scientists are still discovering new plant and animal species today. 

[Read more…] about Deforestation In The Amazon Rainforest

Natural Geoengineering

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The term geoengineering has started to appear in discussions about how to combat climate change.  Mostly, it is used to describe using technology to tinker with the global environment, for example, by artificially enhancing the atmosphere’s ability to reflect the sun’s rays back out into space and thereby cooling the planet.

[Read more…] about Natural Geoengineering

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