Sarah Ruiz, Author at Woodwell Climate

“Why not float the aquatic greenhouse gas chamber on a surfboard?” Tropics Program Director Dr. Mike Coe suggested in one of our team meetings, and I could feel the gears in my brain begin turning. I started a sketch… If mounted on a surfboard, we would need a method to open the chamber, flushing it with outside air. Back in my office, I asked Google “what turns electrical energy into mechanical energy?” Google was quick to respond, “Motor.” Right, thank you, Google. Next, I typed, “motor that pushes something up.” Google replied, “linear actuator.” Three clicks later and I had ordered my first linear actuator for 35 bucks.

Three days later, that linear actuator sat expectantly on my desk. One red wire and one black wire, “12V DC” printed on its side. I turned back to Google, “How to wire a linear actuator?” Opening the first hit, I skimmed through the photos and diagrams. None of them striking my fancy, I moved on to the second hit: Step-by-step instructions, clear photos, even open-source code to program my Arduino microcontroller board – nice! Within an hour, my linear actuator was extending and retracting on command, ready to be mounted in an autonomous greenhouse gas chamber.

Adding the actuator to my sketch, I popped into Senior Research Scientist Kathleen Savage’s office to hear her thoughts. Savage always has new ideas brewing, and she suggested adding a feature that would allow the chamber to function on water and on land. The chambers are the product of a Fund for Climate Solutions (FCS) grant led by Savage to quantify carbon dioxide and methane emissions from small water bodies like lakes, ponds, and reservoirs. Because there are no low-cost and auto-sampling tools available on the market, we have been developing a new instrument to measure these emissions.

DIY science

“Chamber” is a fancy word for the upside-down buckets we use to measure how fast greenhouse gasses are released from different surfaces. By resting a bucket upside-down on a patch of soil or grass or water and measuring how fast gas concentrations increase or decrease inside the bucket, we can calculate a “flux” of gas over a set area and time. Common methods of measuring fluxes require manually collecting gas samples from a chamber to be processed in a lab, or connecting the chamber to a high precision analyzer that can cost around $40,000. These methods are costly in salary time and equipment, limiting where, when, and how often people can sample—usually daytime and in accessible areas and times of the year. We need new low-cost and autonomous systems that can measure around the clock to improve carbon emissions estimates. The recent commercialization of cheaper sensors and control systems to operate them, like the Arduino microcontroller, now make these developments possible.

I’m building a new floating chamber that measures aquatic fluxes autonomously using a $15 methane sensor and a $78 carbon dioxide sensor, improving previous designs published by Dr. David Bastviken’s group at Linköping University in Sweden. Powered by a solar panel and battery, the sensors measure gas concentrations, temperature, and humidity inside the chamber every 30 seconds. The data is stored on an SD card and transmitted within 50 meters via radio. The radio transmission allows us to check that the chamber is functioning properly from the shore and to see chamber measurements in real time. When gas concentrations have increased enough to discern a flux, the linear actuator extends to open the chamber, flushing the interior with outside air before retracting to close the chamber again for another flux measurement. Calibrating the chamber with a high precision analyzer in the field shows the low-cost sensors perform well, with an accuracy of approximately 1 ppm for methane and 3 ppm for carbon dioxide.

Field deployment

I first tested chamber prototypes last July on agricultural reservoirs at the Tanguro Field Station in Brazil. At the end of our field campaign, I left one chamber deployed to see how long the electronics would last and which components might eventually fail. After helping me deploy and calibrate the chamber, field technician Raimundo “Santarém” Quintino monitored it, checking its “vital signs” via radio every few weeks. In January, he noticed the linear actuator had stopped pushing the chamber open.

During a follow-up field campaign in March, I brought a couple of extra linear actuators and five more chambers to deploy on additional reservoirs at Tanguro. Tanguro staff and I worked together to modify chamber components that didn’t function well in the first deployment. These modifications included swapping the materials of the floating foam bases and improving the mounting mechanisms of the linear actuator and chamber hinge. Our adjustments were informed by recommendations from a Laboratory Operations Manager at the University of Maine in Orono (Christopher London), whom I met while doing fieldwork at the nearby Howland Research Forest. Woods Hole locals, such as John Driscoll and Fred Palmer of the Woodwell Climate Facilities department, kite foiler and carpenter Tad Ryan, and employees at Eastman’s Hardware, have also offered transformative recommendations on building materials and techniques to stabilize the floating chambers.

Working hands-on with the floating chambers on the reservoirs, Santarém, Dr. Leonardo Maracahipes-Santos, Tanguro’s Scientific Projects Coordinator, and Sebastião “Seu Bate” Nascimento of Tanguro Field Station have made invaluable improvements to the chamber design and deployments. A few of their contributions include advice on safe deployment locations, monitoring and collecting data from the chambers over time, and constructing aluminum and galvanized steel components for the floating bases. They also designed a new mount for the most recent chamber addition—a bubble trap that uses an inexpensive pressure sensor to autonomously measure the volume of gas released as bubbles.

Freshwater ecosystems worldwide emit nearly half as much carbon dioxide and methane as fossil fuel combustion. On the Amazon-Cerrado frontier, where Tanguro is located, there are hundreds of thousands of small agricultural reservoirs, which are important, yet overlooked, greenhouse gas sources. These artificial ponds—installed to provide drinking water for cattle, facilitate road crossings, or supply energy at the farm scale—can persist for decades, creating low-oxygen conditions that drive methane production. Monthly sampling of six reservoirs over a year by Water Program Director Dr. Marcia Macedo revealed high methane and carbon dioxide emissions, varying with season and reservoir size. But these measurements did not capture the significant variability that can occur on daily, monthly, and annual time scales, including transient “hot spots” and “hot moments” of high greenhouse gas emissions.

This lack of frequent measurements hinders climate scientists’ ability to integrate emissions at the reservoir scale in order to estimate cumulative greenhouse gas emissions at the landscape scale. The autonomous floating chambers will address that gap, enabling comprehensive carbon monitoring and modeling of the reservoirs.

From the tropics to the Arctic

Additionally, these chambers are versatile tools that can be used across different environments. Funded by a subsequent FCS grant, six new floating chambers will accompany me to the Yukon-Kuskokwim Delta, Alaska, this summer to measure greenhouse gas emissions from Arctic ponds. The chambers will supply the frequent data necessary to constrain the LAKE model utilized by Arctic Program scientists Dr. Elchin Jafarov and Andrew Mullen. The model predicts variations in carbon emissions from ponds, providing insight into processes regulating methane and carbon dioxide. By applying the LAKE model to both Arctic ponds and Amazon reservoirs, we can gain a deeper understanding of their impacts on regional greenhouse gas budgets.

“Deploying floating chambers will streamline the process of gathering aquatic data and enhance the temporal resolution of the data, which is vital for modeling and currently absent in existing datasets,” notes Jafarov.

Problem-solving and collaboration

While calibrating the low-cost sensors in our boat one March afternoon, Santarém and I noticed the linear actuator on another nearby chamber wasn’t retracting and extending as it should. Expecting another replacement was in store, we tuned into the radio and popped open the electronics case to check for “symptoms.” Blinking lights and radio silence revealed an entirely new and perplexing issue causing the malfunction.

Building this system from the ground up over the last year, the one constant has been mind-bending electronics puzzles that keep me up at night. As a biogeochemist by training, these problems usually require some tinkering, a dictionary, a lot of Googling, and sometimes bugging electrical engineers down the street at the Woods Hole Oceanographic Institution (Lane Abrams) and Spark Climate Solutions (Bashir Ziady), whose advice and contributions have substantially improved the chambers’ electrical designs. Each problem can usually be traced to a perfectly logical, satisfying solution, leaving me feeling wiser and excited to tackle the next one. I’ve tracked this new problem down to something potentially involving a “memory-leaking variable declaration” in my new bubble trap programming code. I might’ve fixed it with a “watchdog timer.” Both are new words for me, too. If the watchdog timer doesn’t pan out, Santarém and I will try another fix.

Designing, building, and testing these chambers has been an iterative and constantly evolving process. What works well? What doesn’t? How can we do this more simply? Using less energy? For a lower cost? How can we improve the design so that other researchers can easily build these floating chambers as well? Soon we plan to publish open-source instructions detailing how to build and troubleshoot the floating chambers—I have already sent preliminary instructions to three interested research groups. I’m lucky to collaborate with many talented people from Woods Hole to Maine and Brazil, many of whom are as new to chambers and fluxes as I am to engineering. Nevertheless, these floating chambers incorporate a brilliant flourish from each of them.

Andrea “Andie” Norton is an ecologist studying the world’s changing rivers. She examines patterns in temperature and nutrients to assess the response of watersheds to climate change, and to build a record of how river environments are changing that could help flag current threats, predict future changes and develop strategies for successful management.

Did the models predict this?

The dramatic scenes of heat and extreme weather last year prompted many to ask why temperatures had seemingly spiked way above the trend line. Was this unexpected? Was it out of the range of what scientists had modeled? Woodwell Senior Scientist, Dr. Jennifer Francis says not entirely.

“Almost exactly a year ago,” says Francis, “we had just come out of three years of La Niñas and we came close to breaking global temperature records then, even though La Niñas tend to be cooler than neutral or El Niño years. And then along came the strong El Niño of 2023.”

El Niño and La Niña are two extremes of a natural phenomenon that impacts weather patterns across the Pacific, and around the world. In an El Niño year, the prevailing trade winds that normally push warmer waters into the western tropical Pacific—allowing cooler water to well up along the western coast of the Americas—are reversed, resulting in hotter ocean surface temperatures in the eastern equatorial Pacific. When the ocean is hotter than the air above it, that heat is released into the atmosphere, often making El Niño years record breaking ones for global temperatures.

“Last year’s spike looks a lot like the last big El Niño event in 2015-2016. It’s just that now the whole system is warmer. So to me, it wasn’t at all a surprise that we smashed the global temperature record in 2023,” says Francis.

The spike put global temperatures far above the average of climate model simulations, but that doesn’t mean the models didn’t account for it. Risk Program Associate Director, Dr. Zach Zobel, says that averages tend to smooth out natural year-to-year fluctuations, when in fact the upper and lower ranges of model predictions do encompass temperatures like the ones seen in 2023.

“It was well within the margin of error that you would expect for natural variations,” says Zobel.

How does ocean heat impact the climate?

One element of last year’s heat, one that wasn’t necessarily forecasted, was the simultaneous appearance of several ocean heat waves around the globe. The ocean absorbs the vast majority of heat trapped by greenhouse gasses, and that heat can be released under the right conditions. El Niño is one example, but in 2023 it coincided with other not-so-natural marine heat waves across the world.

“In pretty much every single ocean right now there are heat waves happening, which is something quite new,” says Francis.

A couple of dynamics could be driving this. One possibility is that, after three years of La Niñas, in which equatorial Pacific ocean temperatures were generally cooler than the air, the ocean simply absorbed a lot of heat, which was then primed to be released in an El Niño year. Another, Zobel suggests, could be recent shipping laws that required shipping vessels to eliminate sulfate emissions by 2023. Sulfates are a pollutant that may have been helping bounce back solar radiation, hiding the true extent of warming.

“Usually when there’s an El Niño, the eastern tropical Pacific is very warm, but it doesn’t actually drive up ocean temperatures everywhere,” says Zobel. “That was the biggest surprise to me: how warm the northern hemisphere of the Atlantic and Pacific were for most of last year and into 2024.”

Ocean heat waves are typically long-lived phenomena, lasting many months, and so can be a useful tool for meteorologists looking to predict 2024’s extreme weather events.

“The good news is that it provides some kind of long-term predictability about weather patterns in the upcoming year,” says Francis. “The bad news is that they tend to be unusual weather patterns, because those ocean heat waves aren’t usually there.”

Will next year be hotter?

So are we in for another, hotter year after this one? Risk Program Director Dr. Christopher Schwalm says it’s likely.

“Warming predictions for 2024 from leading scientists all forecast a higher level of warming this year than last year,” says Schwalm.

Already, March 2024, was the 10th month in a row to break temperature records. Zobel says it’s typical for the year following an El Niño peak to maintain high temperatures.

“Because the ocean spent a good amount of the year last year warmer than average, that energy is typically dispersed throughout the globe in the following year,” says Zobel. “So even though the tropical Pacific might return to normal, that energy is still in the system.”

However, atmospheric scientists are already seeing signs that El Niño is slowing down and flipping to its counterpart, La Niña, adding another layer of complexity to predictions for 2024.

“The 2024 hurricane season is a large concern,” says Zobel. “La Niña is a lot more conducive to tropical cyclone development. If we combine above average numbers with the amount of energy that storms have to feed on, it’ll be a shock to the system.”

What does this mean for 1.5?

In the discussions around 2023’s temperatures, one number dominates the conversation: 1.5 degrees C. This is the amount of warming countries around the world agreed to try to avoid surpassing, in accordance with the United Nations’ 2015 Paris Climate Agreement. Estimates from Berkeley Earth say that 2023 may have been the first year spent above that threshold.

This assertion may take several years to verify— one year spent physically above 1.5 degrees of warming does not indicate the UN threshold has been permanently passed. What scientists are looking for is a clear average trend line rising above 1.5 degrees C without coming back down, and for that you need several years of data. That, regrettably, creates a lag time between climate impacts and updating climate policy. But, for many, the debate around the arbitrary 1.5 degree goal has become a distraction. Schwalm says scientists and policy-makers should be focusing on urgently combating climate change whatever the numbers say.

“We are already living in a post-Paris Agreement reality,” says Schwalm. “The sooner we admit that and reimagine climate policy, the better.”

“Actual real world impacts are going to be there, whether we’re at 1.48 or 1.52,” says Zobel.

And Francis agrees. “There are so many indicators telling us that big changes are underfoot, that we are experiencing major climate change, but reaching 1.5 isn’t going to all of a sudden make those things worse. It’s just one more reminder we’re still on the wrong track and we’d better hurry up and do something.”

When it comes to reversing climate change, trees are a big deal. Globally, forests absorb nearly 16 billion metric tonnes of carbon dioxide per year, and currently hold 861 gigatonnes of carbon in their branches, leaves, roots, and soils. This makes them a valuable global carbon sink, and makes preserving and maintaining healthy forests a vital strategy in combating climate change.

But not every forest absorbs and stores carbon in the same way, and the threats facing each are complex. A nuanced understanding of how carbon moves through forest ecosystems helps us build better strategies to protect them. Here’s how the world’s different forests help keep the world cool, and how we can help keep them standing.

Tropical forest carbon

Tropical rainforests are models of forest productivity. Trees use carbon in the process of photosynthesis, integrating it into their trunks, branches, leaves, and roots. When part or all of a tree dies and falls to the ground, it is consumed by microorganisms and carbon is released in the process of decay. In the heat and humidity of the tropics, vegetation grows so rapidly that decaying organic matter is almost immediately re-incorporated into new growth. Nearly all the carbon stored in tropical forests exists within the plants growing aboveground.

Studies estimate that tropical forests alone are responsible for holding back more than 1 degree C of atmospheric warming. 75% of that is due simply to the amount of carbon they store. The other 25% comes from the cooling effects of shading, pumping water into the atmosphere and creating clouds, and disrupting airflow.

In many tropical forest regions, there is a tension between forests and agricultural expansion. In the Amazon rainforest, land grabbing for commodity uses like cattle ranching or soy farming has advanced deforestation. Increasing protected forest areas and strengthening the rights of Indigenous communities to manage their own territories has proven effective at reducing deforestation and its associated emissions in Brazil. “Undesignated lands” have the highest levels of land grabbing and deforestation.

Fire has also become a growing threat to the Amazon in recent years, used as a tool to clear land by people illegally deforesting. When rainforests have been fragmented and degraded, their edges become drier and more susceptible to out-of-control burning, which weakens the forest even further. Enforcing and strengthening existing anti-deforestation laws are crucial to reduce carbon losses.

In Africa’s Congo rainforest, clearing is usually for small subsistence farms which, in aggregate, have a large effect on forest loss and degradation. Mobilizing finance to scale up agricultural intensification efforts and rural enterprise within communities, while implementing protection measures, can help decrease the rate of forest destruction. Forests and other intact natural landscapes such as wetlands and peatlands could be the focus of climate finance mechanisms that encourage sustainable landscape management initiatives.

Temperate forest carbon

Much of the forest carbon in the temperate zone is stored in the trees as well— particularly in areas where high rainfall supports the growth of dense forests that are resilient against disturbances like drought or disease. The temperate rainforests of the Northwestern United States, Chile, Australia, and New Zealand contain some of the largest and oldest trees in the world.

Two thirds of the total carbon sink in temperate forests can be attributed to the annual increase in “live biomass”, or the yearly growth of living trees within the forest. This makes the protection of mature and old-growth temperate forests paramount, since older forests add more carbon per year than younger ones and have much larger carbon stocks. Timber harvesting represents one of the most significant risks to the carbon stocks in temperate forests, particularly in the United States where 76% of mature and old growth forests go unprotected from logging. Fire and insects are also significant threats to temperate forests particularly in areas of low rainfall or periodic drought.

Maintaining the temperate forest sink means reducing the area of logging, by both removing the incentive to manage public forests for economic uses and by providing private forest owners with incentives to protect their land. Low-impact harvesting practices and better recycling of wood products can also help bring down carbon losses from temperate forests. In areas threatened by increasingly severe wildfires, reducing fuel loads especially near settlements can help protect lives and property.

Boreal forest carbon

In boreal forests, the real wealth of carbon is below the ground. In colder climates, the processes of decay that result in emissions tend to lag behind the process of photosynthesis which locks away carbon in organic matter. Over millennia, that imbalance has slowly built up a massive carbon pool in boreal soils. Decay is even further slowed in areas of permafrost, where the ground stays frozen nearly year round. It estimated that 80 to 90% of all carbon in boreal forests is stored belowground. The aboveground forest helps to protect belowground carbon from warming, thaw, decay, and erosion.

Wildfire— although a natural element in boreal forests— represents one of the greatest threats to boreal forest carbon. With increased temperatures, rising more than twice as fast in boreal forests compared to lower latitudes, and more frequent and long-lasting droughts, boreal forests are now experiencing more frequent and intense wildfires. The hotter and more often a stand of boreal forest catches fire, the deeper into the soil carbon pool the fire will burn, sending centuries-old carbon up in smoke in an instant. Logging of high-carbon primary forests is also a big issue in the boreal.

The number one protection for boreal forest carbon is reducing fossil fuel emissions. Only reversing climate change will bring boreal fires back to the historical levels these forests evolved with. In the meantime, active fire management in boreal forests offers a cost effective strategy to reduce emissions— studies found it could cost less than 13 dollars per ton of carbon dioxide emissions avoided. Strategies for fire management included both putting out fires that threaten large emissions, and controlled and cultural burning outside of the fire season to reduce the flammability of the landscape.

Drought, driven by a combination of El Niño and climate change, has disrupted shipping through the Panama Canal in recent months. Dropping water levels in Lake Gatun forced Panama Canal authorities to pose restrictions on the number of ships that can pass the canal, dropping from the normal 38 down to 24 transits a day by November 2023, causing long queues at nearby ports as ships wait their turn to pass. If the restrictions remain in place through 2024, there could be up to 4,000 fewer ships—with cargo ranging from children’s toys, to solar panel components, to life-saving insulin—passing the canal in 2024. Delay and disruption along shipping routes will only become a more common occurrence in a warmer world. These 7 graphics show how drought threatens serious disruptions to the global supply chain.

1. Panama in Drought

Panama is currently suffering a prolonged drought that began in early 2023 and has not let up. In October, rainfall was 43% lower than average levels, making it the driest October since the 1950s. For the area around the canal, 2023 was one of the driest two years since record keeping began in the country.

2. El Niño-driven dryness exacerbated by climate

Panama’s severe drought is being exacerbated by the double-whammy of a strong El Niño and record-breaking global warming— exceeding the pre-industrial temperature average by 1.35 C. El Niño is a natural climate fluctuation that brings warmer-than-average air and ocean waters to the West coast of the Americas. That influx of warmth can vary in strength and last between nine and twelve months, and the National Oceanic and Atmospheric Administration (NOAA) predicts it will continue into at least April of 2024.

The severity of El Niño fluctuations is linked to climate change. Climate modeling shows swings between El niño and its counterpart La niña have been growing more extreme, resulting in the more frequent and intense events seen in the past few decades Under high emission scenarios, in which we don’t get warming in check, El Niño events could become 15-20% stronger.

3. Gatún Lake levels continue to drop

The drought has had a particularly profound effect on the man-made Gatún Lake, which holds the water supply that operates the Panama Canal. On January 1, 2024 water levels in Gatún Lake were lower than in any other January on record, almost 6 ft lower than January 1, 2023. Millions of gallons of water from Gatún, along with other regional lakes, are used to fill the locks that raise ships above sea level for the passage over Panama’s terrain. Insufficient water supply jeopardizes ship passage

Not only does Gatún Lake feed the locks that power the Canal, it also supplies drinking water to millions of residents in the central region of the country, including two major cities: Panama City and Colón. As both Panama’s population and the scale of global shipping has grown, there has been greater demand on the lake for freshwater.

4. Less water means fewer, smaller ships

In response to dropping water levels, Panama Canal Authorities have been forced to institute restrictions on ship passages. Ship transits are currently limited to 24 per day until April of 2024, when the authorities will re-evaluate at the start of the rainy season. The number of ship passages was 30% lower than usual by the end of 2023. The unreliability of transit through Panama has already prompted some ships to re-route.

Lower water levels also restrict the size of ships that can pass through the canal, as larger, heavier vessels sit lower in the water, putting them at higher risk of running aground in shallower waters. Large ships also require more lake water to lift them in the locks. As global shipping volume has grown, many shipping fleets have, too— relying on massive vessels that can carry more goods, but are harder to navigate through shallow waterways like the Panama Canal.

5. Disruptions in Panama affect global trade

The Panama Canal accounts for 5% of global shipping, so disruptions here affect the worldwide supply chain, resulting in delayed shipments, more fuel usage, and GDP losses.

The impacts of shipping disruptions in the Panama Canal are also being compounded by political events in the Red Sea. The Suez Canal, an alternative route for ships bound between Europe and Asia, has also had shipping disrupted by attacks from the Houthis, a Yemeni military group targeting Israel-bound ships. With both the Panama and Suez Canals becoming less reliable routes, more ships will be forced to take the long way around— traveling down to the southern points of Africa and South America.

6. Arctic ship travel does not offer an alternative route

Far to the north, another waterway is being rapidly altered by climate change. As the Arctic warms faster than any other place on the planet, summer sea ice has been disappearing at a rate of almost 13% per decade. This has opened up new lanes of ice-free water that some countries are eying as potential new routes. But navigating through a melting Arctic is still dangerous, and the majority of new ship traffic in the Arctic is comprised of smaller military or fishing boats, rather than the large shipping vessels used to carry commercial cargo.

Furthermore, increased ship traffic in the Arctic has the potential to further emissions, as melting ice could open up access to new sources of oil and natural gas— perpetuating climate warming.

7. Temperatures are still rising

Though December rains saved Panama Canal officials from instituting further restrictions on ship passage, the region is still experiencing El Niño, and sea surface temperatures in early 2024 have continued to climb higher than 2023. Each day in 2024 has recorded the highest temperatures on record for that calendar date. The only path to stabilizing global shipping lies in stabilizing the global climate.

River,

It was when you became sick that I truly realized how much you mean to me. How long I have loved you, needed you, learned from you. My entire life I have tried to be self sufficient, but now I realize how dependent I am, and always have been, on you.

It is funny to think that I have known you my entire life. Even though I spent most of my earlier years with your cousin Big Blue, I recall seeing you from afar. You were always drifting by our house each day to visit the cranberry bogs. You ran alongside the trails that I walked with the dogs. They swam with you afterwards to cool off, but I never joined. You always seemed busy, hosting pool parties with the swans and snapping turtles. I did not think much of you then. Honestly you were a little too intimidating for my younger self.