Carbon ‘bank’ at risk of failure: Scientists trying to determine what will happen to massive carbon stores as rainforests dry out — #Colorado State University #ActOnClimate

View of one of the rainforests studied by CSU researcher Daniela Cusack, as seen from a motorboat on the Panama Canal. Researchers had to access the forests in the study by boat.

Click the link to read the article on the Colorado State University website (Jayme DeLoss):

Tropical rainforests store 25%-40% of global soil carbon, though they occupy only 7% of Earth’s land area. By functioning as a carbon sink, tropical forests prevent more severe effects from climate change.

A research team led by a Colorado State University scientist found that climate change will impact tropical forests’ ability to store carbon. Their study reveals that persistent drying in tropical forests, an anticipated result of climate change, leads to carbon loss from the most fertile soils – and that soil nutrients play an important role in how much carbon is released and when. 

“Tropical forests can be really sensitive to reductions in rainfall,” said Daniela Cusack, lead author and an associate professor in the Department of Ecosystem Science and Sustainability, “and they have some of the largest stores of carbon on Earth. As climate is drying, that carbon is vulnerable.” 

Climate change is reducing rainfall in some places and causing more year-to-year variation. Some tropical forests already have been documented as drying.  

“All of that carbon that’s stored in rainforests right now is like a bank,” Cusack said. “We’re banking all that carbon and anything that releases that carbon is going to exacerbate climate change and impact everybody.” 

Unexpected results

Daniela Cusack, an associate professor in Ecosystem Science and Sustainability, led the PARCHED study, which revealed surprising results about how tropical forests will react to climate change.

Cusack and her team assessed the effects of natural seasonal drying and chronic reduced rainfall on carbon fluxes in tropical forests. They found that natural seasonal drying suppressed the release of carbon dioxide. 

“There was some resilience at first, which makes sense because these are seasonal forests, so they’re used to a dry season,” Cusack said. “But it seems like after that initial resilience, we’re hitting a threshold where things are shifting more rapidly in some tropical forests.” 

The ecosystem model they used in the study predicted that persistent drying would increase the release of carbon dioxide from more fertile and wetter tropical forests but decrease CO2 fluxes from drier tropical forests. 

“We had predicted that the wettest site would be most sensitive to drying,” Cusack said. “It’s the least adapted to drier conditions.” 

The expectation was that as the wetter sites dried down a little, they would become more favorable for microbes, which decompose carbon in soil, turning it back into carbon dioxide. 

“What we saw was the opposite of what’s been hypothesized for these tropical forests,” Cusack said. The site they expected to have the biggest carbon loss actually lost the least carbon. 

Perhaps the microbes can’t thrive in infertile soil, Cusack said, or maybe microbial activity is just slower to ramp up in the wettest soils because they take longer to dry out. Cusack said more research is needed to determine why the results disagreed with the model. 

Carbon loss via respiration did increase significantly with persistent drying in the more fertile soils, suggesting nutrients play an important role in CO2 fluxes.  

Withholding rain from the rainforest

The study, called PARCHED for PAnama Rainforest CHanges with Experimental Drying, measured the effects of natural seasonal drying and experimental chronic drying on soil carbon storage in four distinct tropical forests in Panama.  

The forests encompassed a broad range in natural rainfall and soil fertility. This allowed the researchers to compare how different kinds of tropical forests would respond to drying. 

With initial investment from the National Science Foundation, they took two years of baseline measurements, starting in 2015. Then the team started monitoring carbon fluxes under conditions imposed by experimental drying over plots of rainforest in 2018, thanks to funding from the Department of Energy. 

To induce artificial drying, the team built partial greenhouse roofing over plots measuring 10 meters by 10 meters in each of the four forests. The roofing, which was below the forest canopy, diverted about half of the rainfall from the soil at each site. Trenches lined with plastic kept moisture from seeping into the study plots.  

PARCHED study field team, from left: Amanda Cordeiro (CSU grad student), Jackie Reu (intern), Edwin Garcia (Panama technician), Daniela Cusack and Lee Dietterich (CSU postdoc and co-author).

The study, published in Global Biogeochemical Cycles, showed that different tropical forests will respond to climate change differently and on different time frames, and that fertile soils may be the first to react with big carbon losses across the tropics. 

Researchers were surprised that soil nutrients seem to have as big an effect as soil moisture, which necessitates updates to predictive models. 

“If there aren’t enough nutrients, the microbes don’t seem to respond as much to changes in moisture,” Cusack said. 

Scientists have not observed changes in plant growth or conversion of CO2 to oxygen via photosynthesis yet, which makes sense, Cusack said, because plants are bigger organisms that take longer to grow. 

“Microbes are small creatures, and they tend to respond much more quickly to climate change and other kinds of disturbance,” she said. 

With continued experimental drying, the other plots also are trending toward carbon loss, Cusack said – one more reason to address emissions problems and increase carbon sequestration initiatives. 

“Everyone thinks about temperature change, but I think precipitation change can be more confusing,” Cusack said. “It’s more variable, and it’s changing differently in different places. But drying in the tropics is a real concern as far as these carbon stores.” 

The PARCHED study team built infrastructure to divert about 50% of rainfall from plots measuring 10 meters by 10 meters in four forests in Panama. The forests varied greatly in mean annual precipitation and soil properties.

Improved prediction

Cusack and her team’s results have contributed to improved modeling of rainforest carbon cycling.  

Ecosystem-scale soil carbon models were developed for temperate forests, which is why they don’t simulate saturated, infertile tropical soils very well. The researchers updated the carbon model they worked with to better match their observations. 

Soil fertility is not fully represented in many ecosystem carbon models, especially for the nutrients scarcest in tropical forests, like phosphorus. In many existing soil carbon models, carbon loss predictions are based primarily on soil moisture. Cusack said representing nutrients better in ecological models is an important next step in this research. 

Authors of the study, “Soil Respiration Responses to Throughfall Exclusion are Decoupled from Changes in Soil Moisture for Four Tropical Forests, Suggesting Processes for Ecosystem Models,” are Cusack, Lee H. Dietterich, with CSU’s Department of Ecosystem Science and Sustainability, and Benjamin N. Sulman, with Oak Ridge National Laboratory. The Department of Ecosystem Science and Sustainability is part of the Warner College of Natural Resources. 

Navajo Dam operations update April 19, 2023 #SanJuanRiver #ColoradoRiver #COriver

The San Juan River’s Navajo Dam and reservoir. Photo credit: U.S. Bureau of Reclamation

From email from Reclamation (Susan Novak Behery):

At 9:00 AM on April 20th (Thursday), the release at Navajo Dam will be transferred to the 4×4 Auxiliary outlet for a period of 2 hours to allow for SCADA testing.  During this time, the release volume will not change. The release will be transferred back to the power plant after the 2-hour test has concluded. You may expect some silt and discoloration downstream in the river during this time due to the location of the 4×4.

Taming the forest fires of the future ― today: @DenverWater and partners are making landscape-scale changes that may ease the threat of wildfires and protect precious #water supplies

Click the link to read the article on the Denver Water website (Todd Hartman):

In the race to protect homes and communities ― and water supplies ― from the intensifying threat of wildfire, Front Range organizations spent urgent years hustling to thin dense and overgrown forests in scattered patches.

Cutting trees and clearing brush ideally would ease the risk of catastrophic fire by reducing what could burn and slowing a fire’s spread in a less crowded forest.

In September 2019, firefighters quickly contained the Payne Gulch fire in Pike National Forest. Work done in 2017 to reduce the density of the trees in the area, from 256 to 44 trees per acre, helped make it more difficult for the 2019 fire to spread rapidly. Photo credit: U.S. Forest Service.

And that was true. But the approach, while well-meaning and understandable, also was disorganized and scattershot.

“Organizations were frantically out there working on their own,” explained Madelene McDonald, a watershed scientist at Denver Water focused on protecting water supplies from wildfire. “These were shotgun treatments, or what is sometimes called ‘random acts of restoration.’ It was 500 acres here, then 300 acres there.”

Things are changing ― for the better. And Denver Water is at the forefront.

Denver Water scientist earns rare slot on Congressional wildfire commission.

With greater coordination, more resources and a more strategic approach, agencies and communities are beginning to create larger, more connected swaths of thinned-out forests. 

Experts believe these larger swaths can better prevent the kind of massive damage to waterways, reservoirs — and the forests themselves — that have marked the last quarter-century of epic wildfire in Colorado.

“We are recognizing that we can’t be working independently. We need to be collaborating and doing strategic cross-boundary planning. We can get far more done together,” McDonald said. “The risk is still there, but we are moving the needle.”

Focus on the Pike National Forest

One of the clearest examples of this strategic shift can be found in the South Platte Ranger District, in a region near Bailey located south and west of Denver.

Here, partnerships involving the U.S. Forest Service, Denver Water, the Colorado State Forest Service and other state and local organizations are driving landscape-scale work that will provide greater protection for forests and for Denver Water’s supplies in an era of a warming climate and hotter, larger, more damaging forest fires.

A view of the trees, now stacked as logs, that were thinned as part of the Jerome Miller/Miller Gulch Project to reduce wildfire risk and protect the North Fork of the South Platte River, a key supply for Denver Water. Photo credit: Denver Water.

Much of the work is occurring under the banner of the Jerome Miller/Miller Gulch Project, an effort focused on an area of the Pike National Forest that lies between the North Fork and the South Platte rivers and upstream from where the two waterways merge near Strontia Springs Reservoir, a temporary pool for 80% of Denver Water’s supply.

The project is expanding a series of forest treatments in the region that collectively are designed to limit future fires ability to spread quickly and grow in intensity. That, in turn, should lessen wildfire impacts to the North Fork of the South Platte, a stretch that conveys critical supplies of water flowing from Dillon Reservoir to the metro area.

Parts of this general region in the South Platte River watershed were the epicenter of two major fires in 1996 and 2002 that together burned more than 150,000 acres, devastated landscapes and left reservoirs clogged with thousands of tons of sediment that poured from the scorched, treeless landscape left by the fires. 

Those two fires, named the Buffalo Creek and Hayman, set Denver Water and other land management agencies on the course they are on today ― to collaborate on the ground to ease the risk of future catastrophic fires.

Examples of success 

Already, the partnership’s work has resulted in tangible success stories.

In 2019, a fire broke out in an area called Payne Gulch in the Pike National Forest. As part of a series of forest management projects in the region, this area had been thinned in 2017.

“The fire could have blown up to be a pretty catastrophic fire, but wildland firefighters were able to access and suppress the fire effectively because of the thinning,” McDonald said. “That’s a shining example of where we’ve seen this work pay off. The connectivity between treated areas is increasing and attracting more and more work in that area.”

This photo shows the result of work to reduce forest density in the Jerome Miller/Miller Gulch Project on U.S. Forest Service land. Photo credit: Denver Water.

In perhaps the highest profile example, the partnership’s work to develop fuel breaks protected about 1,400 homes and as much as $1 billion in value in Silverthorne during the Buffalo Fire in Summit County in 2018. The work has also protected Denver Water’s Dillon Reservoir, Denver Water’s largest water storage facility.

Success has many fathers (as the saying goes), but there’s little question that Denver Water’s From Forests to Faucets partnership with the U.S. Forest Service, Natural Resources Conservation Service, Colorado State Forest Service and Colorado Forest Restoration Institute is a key part of the story driving greater investment and partnerships to get ahead of big fires in Colorado.

In 2020, the Williams Fork fire hit one source of Denver Water supply.

All told, partners have committed more than $96 million to the From Forests to Faucets partnership, from its inception in 2010 through work planned into 2027.

In total, Denver Water and partners have treated more than 120,000 acres of forested land since 2010, with nearly two-thirds of that within the South Platte Basin. Local organizations involved in the South Platte Basin work include Jefferson County Open Space, Jefferson Conservation District, Aurora Water and the Coalition for the Upper South Platte. 

Feds point to Colorado

Federal officials gathered Feb. 9 for a news conference in Broomfield to highlight new congressional funding for forest work and called such partnerships in Colorado “a template for the nation.”

At that event, Homer Wilkes, the U.S. Department of Agriculture Undersecretary of Natural Resources and Environment, announced $37 million in federal money for priority landscapes along the Front Range in 2023, including areas in the South Platte watershed.

Last year, the region attracted $18 million in federal dollars. All of that money comes on top of recent funding at the state level of more than $80 million. 

“Investing proactively in protecting forests and watersheds is a smart business decision. You can see our partners increasingly understand that as state and federal resources pour in to help reduce the impacts of, and potential for, big fires,” said Christina Burri, who has for years developed and strengthened Denver Water’s interagency collaboration.

Burri noted that with the new flow of state and federal money, Denver Water is seeing up to a tenfold return on the utility’s investment into From Forests to Faucets.

“It is amazing to see,” she said.

Outgoing Denver Water CEO/Manager Jim Lochhead said the big rise in funding to protect water supplies and communities is a tribute to Denver Water’s years of focus on the issue.

“It is just one more example of how a utility can achieve results by leaning into collaboration and partnerships, and by leading in innovation,” Lochhead said. 

In August of 2022, Denver Water commissioners joined the utility’s watershed scientists to visit the area being treated as part of the Jerome Miller/Miller Gulch Project. Left to right: Alison Witheridge, Christina Burri, Commissioner Craig Jones, Commissioner Dominique Gómez, Madelene McDonald, Commissioner Tyrone Gant. Photo credit: Denver Water.

This Week’s Topsoil Moisture % Short/Very Short (S/VS) by @usda_oce

The Lower 48 saw a 3% rise in S/VS, w/ big jumps in the Mid-Atlantic and Northeast. The Central/Southern Plains continue to have high levels of S/VS. Most of the West and Southeast (except FL) have low levels.

Colorado Water Trust Launches Rebrand @COWaterTrust

Helms Ditch Headgate. Photo credit: Colorado Water Trust

Here’s the release from the Colorado Water Trust (Dana Hatlelid):

April 17, 2023: Since 2001, Colorado Water Trust has restored over 20 billion gallons of water to 600 miles of Colorado’s rivers and streams. Upon our founding, water transactions for environmental benefit were controversial and there were many skeptics of their viability. It took over a decade of tireless outreach and negotiations to prove it was possible and start implementing projects that restored water to rivers.

We stand at the beginning of a new era. Coloradans see clearly the impact climate change and population growth has had on our rivers. We read and hear about compact compliance and federal regulations and know we are in a time of grave concern for the west’s water future. In Colorado, water transactions for environmental benefit are gaining quickly in importance and regularity. Five years ago, an offer of water at Colorado Water Trust was rare. Today, our staff are fielding inquiries with increasing frequency. Colorado is changing, and Colorado Water Trust aims to help turn the tide.

We are scaling up our impact, implementing visionary solutions for low-flowing rivers, instituting new programs, bringing more people together, and spreading out our team across the state. As we enter this new stage of growth, our Board and Staff decided it was time to modernize our brand. We revamped our mission statement, created a new vision and values statements, designed a bright and colorful logo and brand, and constructed a brand-new website. After nearly a year of effort and thoughtful consideration, we present to you a renewed Colorado Water Trust.

We invite you to join us in celebrating our hard work which we couldn’t have done without the support of our community.

Consider doing your part for Colorado’s rivers and returning the amount of water you use in your household annually to Colorado’s rivers and streams with myRiver Balance:

Greenhouse gases continued to increase rapidly in 2022: Carbon dioxide, methane and nitrous oxide rise further into uncharted levels — NOAA #ActOnClimate #KeepItInTheGround

Click the link to read the article on the NOAA website (Theo Stein):

Levels of carbon dioxide (CO2), methane and nitrous oxide, the three greenhouse gases emitted by human activity that are the most significant contributors to climate change, continued their historically high rates of growth in the atmosphere during 2022, according to NOAA scientists. 

The global surface average for CO2 rose by 2.13 parts per million (ppm) to 417.06 ppm, roughly the same rate observed during the last decade. Atmospheric CO2 is now 50% higher than pre-industrial levels. 2022 was the 11th consecutive year CO2 increased by more than 2 ppm, the highest sustained rate of CO2 increases in the 65 years since monitoring began. Prior to 2013, three consecutive years of CO2  growth of 2 ppm or more had never been recorded. 

The Global Monitoring Division of NOAA/Earth System Research Laboratory has measured carbon dioxide and other greenhouse gases for several decades at a globally distributed network of air sampling sites. Credit: NOAA Global Monitoring Laboratory

Atmospheric methane, which is far less abundant but much more potent than CO2 at trapping heat in the atmosphere, increased to an average of 1,911.9 parts per billion (ppb). The 2022 methane increase was 14.0 ppb, the fourth-largest annual increase recorded since NOAA’s systematic measurements began in 1983, and follows record growth in 2020 and 2021. Methane levels in the atmosphere are now more than two and a half times their pre-industrial level.

This graph shows the globally-averaged, monthly mean atmospheric methane abundance determined from marine surface sites since the inception of NOAA measurements starting in 1983. (Image credit: NOAA Global Monitoring Laboratory)

In 2022, levels of the third-most significant anthropogenic greenhouse gas, nitrous oxide, rose by  1.24 ppb to 335.7 ppb, which is tied with 2014 as the third-largest jump since 2000 and a 24% increase over its pre-industrial level of 270 ppb. The two years of highest growth occurred in 2020 and 2021. Increases in atmospheric nitrous oxide during recent decades are mainly from use of nitrogen fertilizer and manure from the expansion and intensification of agriculture.

This graph shows the globally-averaged, monthly mean atmospheric nitrous oxide abundance determined from marine surface sites since 2001. (Image credit: NOAA Global Monitoring Laboratory)

“The observations collected by NOAA scientists in 2022 show that greenhouse gas emissions continue to rise at an alarming pace and will persist in the atmosphere for thousands of years,” said Rick Spinrad, Ph.D., NOAA administrator. “The time is now to address greenhouse gas pollution and to lower human-caused emissions as we continue to build toward a Climate-Ready Nation.”

NOAA’s measurements vital for understanding emissions trends

NOAA’s Global Monitoring Laboratory collected more than 14,000 air samples from monitoring stations around the world in 2022 and analyzed them in its state-of-the-art laboratory in Boulder, Colorado. Every spring, NOAA calculates and releases the preliminary global average levels of the three primary long-lived greenhouse gases — CO2, methane and nitrous oxide — observed during the previous year. 

Measurements are obtained from air samples collected from sites in NOAA’s Global Greenhouse Gas Reference Network, which includes more than 50 cooperative sampling sites around the world. 

“Our latest measurements confirm that the most important greenhouse gases continue to increase rapidly in the atmosphere,” said Stephen Montzka, NOAA’s Global Monitoring Laboratory senior scientist. “It’s a clear sign that much more effort will be required if we hope to stabilize levels of these gases in the next few decades.”

Carbon dioxide emissions remain the biggest problem 

CO2 is by far the most important contributor to climate change. The main driver of increasing atmospheric CO2 is the burning of fossil fuels, with emissions increasing from 10.9 billion tons per year in the 1960s — which is when the measurements at the Mauna Loa Observatory in Hawaii began — to about 36.6 billion tons per year in 2022, according to the Global Carbon Projectoffsite link, which uses NOAA’s greenhouse gas measurements in its estimates. 

The amount of CO2 in the atmosphere today is comparable to where it was around 4.3 million years ago during the mid-Pliocene epoch, when sea level was about 75 feet higher than today, the average temperature was 7 degrees Fahrenheit higher than in pre-industrial times and studies indicate offsite linklarge forests occupied areas of the Arctic that are now tundra. 

About a quarter of the CO2 emissions from fossil fuels to date have been absorbed by the world ocean, contributing to ocean acidification, which may threaten some fisheries and aquaculture around the world.

Cause of methane increases not fully known 

NOAA’s long-term measurements show that atmospheric methane increased rapidly during the 1980s, nearly stabilized in the mid-1990s and early 2000s, then resumed a rapid rise in 2007. 

A 2022 study by NOAA and NASA scientistsoffsite link suggests that as much as 85% of the increase from 2006 to 2016 was due to increased microbial emissions generated by livestock, agriculture, human and agricultural waste, wetlands and other aquatic sources. The rest of the increase was attributed to increased fossil fuel emissions. 

The exact causes of the recent increase in methane are not yet fully known, said GML carbon cycle scientist Lindsay Lan, a CIRESoffsite link scientist working at the Global Monitoring Laboratory. One possibility, she said, is the influence of a persistent three-year La Nina, which, on average, results in enhanced precipitation over tropical wetland regions, which may increase the activity of microbes that generate methane emissions as a result. NOAA scientists are investigating the possibility that climate change is causing wetlands to give off increasing methane emissions in a feedback loop. 

Opinion: My Continent Is Not Your Giant #Climate Laboratory — Chukwumerije Okereke in the New York Times

Graphic via the skeptics at What’s Up With That

Click the link to read the guest column on the New York Times website (Chukwumerije Okereke). Here’s an excerpt:

Several environmentalists last year presented Africa’s leading climate negotiators with a bold idea: A technology called solar geoengineering could protect their countries from the worst effects of climate change, they said. While insisting they were impartial, representatives from the Carnegie Climate Governance Initiative said that these technologies, which claim to be able to re-engineer the climate itself, either by dimming the sun’s rays or reflecting sunlight away from the earth, could quickly and cheaply turn the tide of dangerously rising temperatures — and that poor countries might have the most to gain.

It wasn’t the first time Westerners have tried to persuade Africans that solar engineering projects may be in our best interest. And it won’t be the last. In May, another international nonprofit, the Climate Overshoot Commission, headquartered in Paris, is hosting an event in Nairobi to help drum up support for research on solar geoengineering and other related technologies it says could be helpful in reducing risks when the world exceeds its global warming targets.

As a climate expert, I consider these environmental manipulation techniques extremely risky. And as an African climate expert, I strongly object to the idea that Africa should be turned into a testing ground for their use. Even if solar geoengineering can help deflect heat and improve weather conditions on the ground — a prospect that is unproven on any relevant scale — it’s not a long-term solution to climate change. It sends a message to the world that we can carry on over-consuming and polluting because we will be able to engineer our way out of the problem.

The solar engineering technology attracting the most attention would use balloons or aircraft to spray large quantities of aerosols — tiny particles of, for example, sulfur dioxide or engineered nanoparticles — into the stratosphere to dim the sunlight. It’s called solar radiation management and it’s highly speculative.Without using the whole earth as a laboratory, it’s impossible to know whether it would dim anything, let alone how it would affect ecosystems, people and the global climate.

These technologies would also theoretically need to be deployed essentially forever to keep warming at bay. Stopping would unleash the suppressed warming of the carbon dioxide still accumulating in the atmosphere in a temperature spike known as “termination shock.” One study found that the temperature change after ending solar radiation management could be up to four times as large as what’s being caused by climate change itself.

The other risk is that geoengineering will divert attention and investments from building renewable energy and other climate solutions in Africa. The continent has received only 2 percent of global investments in renewable energy in the last two decades, and the lack of access to capital is perhaps the biggest obstacle for countries that would like to cut down on fossil fuels.