climate change mitigation

Timber Cities | Earth Wise

October 3, 2022 By EarthWise 2 Comments

More than half of the world’s population lives in cities and by 2100, this percentage is predicted to be much higher. This means that more homes will be built with steel and concrete, which both have very large carbon footprints. According to a study by the Potsdam Institute in Germany, housing a growing population in homes made of wood instead could avoid more than 100 billion tons of carbon dioxide emissions over the remainder of the century. This is about 10% of the remaining global carbon budget for staying below the 2-degree Celsius climate target.

The study presents the alternative of housing new urban populations in mid-rise buildings – no more than 4-12 stories high – that are substantially made of wood. Wood is a renewable resource that carries the lowest carbon footprint of any comparable building material. Trees take up CO₂ from the atmosphere to grow. Producing engineered wood releases far less CO₂ than production of concrete and steel and the finished product continues to store carbon.

The study shows that sufficient wood for new mid-rise urban buildings can be produced without a major impact on food production. The wood would come from timber plantations as well as natural forests. The study also looked at biodiversity impacts and ways that ecosystems could be protected while still providing the necessary timber.

Overall, the Potsdam study demonstrates that urban homes made out of wood could play a vital role in climate change mitigation based on their long-term carbon storage potential coupled with the reduced utilization of the carbon-intensive concrete and steel industries.

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Living in timber cities could avoid emissions – without using farmland for wood production

Photo, posted May 24, 2005, courtesy of Stig Anderson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plant-Based Foods And CO2 Emissions | Earth Wise

September 9, 2022 By EarthWise Leave a Comment

We often hear how eating locally-sourced food is a way to minimize the carbon footprint of our diet. But from a climate impact perspective, this only has a significant impact if transportation is responsible for a large portion of a food’s final carbon footprint. In many cases, the greenhouse gas emissions related to transportation make up only a small portion of the total emissions from food, and what we eat is far more important.

In general, beef and lamb have the biggest climate footprint per gram of protein. Plant-based foods tend to have the smallest impact. Pork and chicken are somewhere in the middle.

According to new research, U.S. food production could reduce its agricultural carbon footprint between 2.5% and 13.5% by embracing plant-based alternatives to beef. The study, from researchers at Cornell University, Johns Hopkins University, and international partners, found that most of the reduction would be achieved by decreasing the number of cows needed for beef production by two to twelve million animals. The research was recently published in the journal Lancet Planetary Health.

However, the researchers also found that acting to reduce climate change in this manner could have unintended consequences. For example, economic models from the research team show that the growth in popularity of plant-based beef could disrupt the agricultural workforce, threatening more than 1.5 million jobs.

But in the big picture, doing nothing will cost much more than doing something to slow climate change. Shifting diets away from meat and other animal products and towards more plant-based foods will help shrink carbon footprints and mitigate climate change. It’s a win-win for the planet and for human health.

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Plant-based ‘beef’ reduces CO2 but threatens ag jobs

Photo, posted November 27, 2018, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

California Trees Are Dying | Earth Wise

August 19, 2022 By EarthWise Leave a Comment

California relies on extensive forests to help reduce the amount of carbon dioxide entering the atmosphere. But extensive drought and increasingly frequent wildfires have been reducing the state’s tree population for the past three decades.

A comprehensive study by a team of scientists from the University of California Irvine used satellite data to study vegetation changes between 1985 and 2021. Across the entire state, tree cover area has declined 6.7% over that time period. The results varied from region to region across the state.

Southern California exhibited the sharpest decline, where 14% of the tree population in local mountain ranges vanished, potentially permanently. In the Sierra Nevada mountains, tree populations were relatively stable until about 2010. After that, a severe drought followed by historically large wildfires resulted in a 8.8% die-off of trees. The northern parts of the state, with higher rainfall and cooler temperatures, fared better, being able to more easily recover from wildfires.

The study goes beyond measuring the tree population of the state and its effects on carbon storage. The data is also important for understanding how changes in forest cover affects water resources and fire behavior in the state.

The decline of trees in California is affecting the carbon storage abilities of the state. The satellite survey showed that as the tree populations have dropped, the state’s coverage of shrubs and grasses has risen, possibly indicating that permanent ecosystem shifts are occurring. The forces contributing to the decline of trees in California are not going away any time soon. As a result, the threat to California’s ability to mitigate the effects of climate change continues to grow.

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UCI study: California’s trees are dying, and might not be coming back

Photo, posted March 24, 2016, courtesy of David Fulmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Mangrove Forests And Climate Change | Earth Wise

August 3, 2022 By EarthWise Leave a Comment

Mangrove forests play a vital role in the health of our planet. These coastal forests are the second most carbon rich ecosystems in the world. A patch of mangrove forest the size of a soccer field can store more than 1,000 tons of carbon. It does this by capturing carbon from the air and storing it in leaves, branches, trunks, and roots.

Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures. These forests can be recognized by their dense tangle of prop roots that make the trees look like they are standing on stilts above the water. These roots allow the trees to handle the daily rise and fall of tides. Most mangroves get flooded at least twice a day. The roots also slow the movement of tidal waters, which allows sediments to settle out of the water and build up on the muddy bottom. Mangrove forests stabilize coastlines, reducing erosion from storms, currents, waves, and tides.

A new study by the University of Portsmouth in the UK looked at the effects of climate change on how carbon is stored in mangrove forests. In mangrove ecosystems, a variety of organisms break down fallen wood. These include fungi, beetle larvae, and termites. Closer to the ocean, clams known as shipworms degrade organic material.

Climate change is disrupting these processes in at least two ways. Rising sea levels are changing the way sediments build up and increased ocean acidity is dissolving the shells of marine organisms like shipworms.

Mangrove forests are crucial to mitigating climate change, and changes to the functioning of the carbon cycle of those ecosystems are a threat to their ability to perform that function.

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Study Reveals How Climate Change Can Significantly Impact Carbon-Rich Ecosystem

Photo, posted March 24, 2014, courtesy of Daniel Hartwig via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Blue Carbon Credits | Earth Wise

June 4, 2021 By EarthWise Leave a Comment

Carbon credits have been around since the late 1990s. The idea is to offset carbon emissions from some carbon emitting activity – anything from a wedding in California to a factory operating in Minnesota – by buying carbon credits earned from a carbon-absorbing activity, such as planting trees in the Amazon.

Blue carbon credits are credits earned by increasing the carbon stored in coastal and marine ecosystems. Coastal ecosystems such as mangroves, tidal marshes, and seagrass meadows in fact sequester and store more carbon per unit area than terrestrial forests and are increasingly being recognized for their important role in mitigating climate change.

Blue carbon credit awards have to date been relatively few and far between and have mostly been granted for mangrove restoration efforts. But mangrove projects are now ramping up dramatically in scope. Scientists are working hard to analyze the amount of carbon in other ecosystem types – seagrasses, salt marshes, seaweeds, and seafloor sediments – so that these systems can also enter the carbon credit market.

Over the past 20 years, conservation scientists have spread over 70 million seeds in the bays of Virginia to restore over 9,000 acres of seagrass meadows that were devastated by disease in the 1930s. The restored meadows are absorbing nearly half a ton of CO2 per acre.

The rules to allow for blue carbon credits are recent and evolving, which is a big deal. The market may currently be small, but it is growing exponentially. But as important as carbon credits are, it is still paramount to decarbonize before turning to offsets for existing emissions.

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Why the Market for ‘Blue Carbon’ Credits May Be Poised to Take Off

Photo, posted July 2, 2009, courtesy of Nicolas Raymond via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change and Komodo Dragons | Earth Wise

October 12, 2020 By EarthWise Leave a Comment

The Komodo dragon is the world’s largest and most iconic lizard. Growing up to 10 feet long and weighing up to 360 pounds, Komodo dragons are endemic to five islands in southeast Indonesia, four of which are part of Komodo National Park, as well as a fifth that has three nature reserves. Komodo dragons have existed on earth for at least four million years, and it’s estimated that 4,000 of them survive in the wild today.

But according to a new study by researchers from the University of Adelaide and Deakin University in Australia, Komodo dragons could soon be driven to extinction. The research team found that the impacts of both global warming and sea level rise are likely to cause a sharp decline in available habitat for Komodo dragons. Current conservation strategies are not enough to avoid climate-driven Komodo dragon population declines.

The study, which was recently published in the journal Ecology and Evolution, involved close collaboration with Komodo National Park and the Eastern Lesser Sunda Central Bureau for Conservation of Natural Resources.

Climate-change-informed decisions should be a common part of conservation practice. According to the research team’s conservation model, Komodo dragons on two of the five Indonesian islands are less vulnerable to climate change. But those two islands might not be enough for the survival of the species. Conservation managers may need to translocate Komodo dragons in the future – to sites where these animals have not been found for decades – in order to protect the species from extinction.

Without taking immediate action to mitigate climate change, the research team says many range-restricted species like Komodo dragons are at risk of extinction.

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Climate change threatens Komodo dragons

Photo, posted August 6, 2016, courtesy of Tony Alter via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Can We Remove Enough CO2 From The Air?

January 9, 2019 By EarthWise Leave a Comment

As atmospheric carbon dioxide levels continue to set new records and the effects of climate change grow stronger, humanity has continued to procrastinate on reducing emissions. As a result, it is increasingly clear that any strategy to avoid runaway climate change will have to involve the use of “negative emissions”- techniques or technologies that actually remove CO2 from the air.

There are both low-tech and high-tech methods for removing carbon dioxide from the atmosphere and both are likely to be needed.

On the low-tech side, afforestation (planting trees where there were none before), reforestation, changes in forest management, rebuilding the carbon backbone in agricultural soils, and the use of energy from waste biomass are all ways to take carbon out of the atmosphere.

On the high-tech side, direct air capture technologies that take CO2 out of the air and store it in the ground are making rapid progress. Right now, they are still very expensive,but that is changing. There is an analogy to wind and solar technology. Not very long ago, both of those technologies were quite expensive but now their costs have plummeted to the point where they are often the cheapest way to make electricity. With sufficient development effort and deployment, direct air capture technology could become quite affordable.

Some people advocate geoengineering as a solution for climate change. While removing carbon dioxide amounts to tackling the root cause of the warming climate,geoengineering would address the problem by changing the climate again in some other way. It is at best an extremely dangerous approach.

Removing CO2 using a combination of natural and man-made techniques is an important part of mitigating the effects of climate change.

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