Methane in the Atmosphere Rises

R B Jackson, M Saunois, P Bousquet , J G Canadell, B Poulter, A R Stavert , P Bergamaschi, Y Niwa , A Segers and A Tsuruta: Increasing anthropogenic methane emissions arise equally from agricultural and fossil fuel sources, Environ. Res. Lett. 15 (2020) 071002 https://iopscience.iop.org/article/10.1088/1748-9326/ab9ed2/pdf.


As you have probably heard or read the lock downs associated with the Covid-19 pandemic has reduced global carbon emissions, albeit temporarily. However, Scientists at the Stanford’s School of Earth Energy and Environmental Sciences believe it is unlikely that methane levels in the environment have seen the same reduction because many of the sources of methane have continued unabated. The paper cited above tells the story or rising methane levels. Methane levels in the atmosphere have risen since 2000. We care about methane because climate scientists estimate that the gas is responsible for about one quarter of the global warming that has happened since industrialization.

According to the paper cited above the amount of methane in Earth’s atmosphere continues to rise. Concentrations of methane now exceed 1875 parts per billion, about 2.5 times as much as was in the atmosphere in the 1850s. The researchers synthesized all known data about methane from the US EPA’s emissions inventories, atmospheric measurements, and models to assemble a global “methane budget” that details which processes add the gas to the atmosphere and which remove it.

 

from the Global Carbon Project

According to their study, wetlands contributed 30% of global methane emissions, with oil, gas, and coal activities accounting for 20%. Agriculture, including enteric fermentation (cow belching), manure management, and rice cultivation, made up 24% of emissions, and landfill gas contributed 11%. Sixty-four percent of methane emissions came from the tropical regions of South America, Asia, and Africa, with temperate regions accounting for 32% and the Arctic contributing 4%.

Methane emissions rose most sharply in Africa and the Middle East; China; and South Asia and Oceania. Each of these three regions increased emissions by an estimated 10 to 15 million tons per year during the study period. The United States followed behind, increasing methane emissions by 4.5 million tons, mostly due to more natural gas drilling, distribution and consumption.Europe was the only region where methane emissions decreased over the study period, attributed to reductions chemical manufacturing and growing food more efficiently with better management of manure and landfills. 

According to Dr. Jackson and his colleagues, curbing methane emissions will require reducing fossil fuel use and controlling fugitive emissions such as leaks from pipelines and wells, as well as changes to the way we feed cattle, grow rice and eat. “We’ll need to eat less meat and reduce emissions associated with cattle and rice farming,” Dr. Jackson said, “and replace oil and natural gas in our cars and homes.”

Rob Jackson is Stanford’s Michelle and Kevin Douglas Provostial Professor. Dr. Jackson and his lab examine the many ways people affect the Earth.  They're currently examining the effects of climate change and droughts on forest and grassland ecosystems. They are also working to measure and reduce greenhouse gas emissions through the Global Carbon Project (globalcarbonproject.org), which Jackson chairs; examples of new research Rob leads include establishing a global network of methane tower measurements at more than 80 sites worldwide and measuring and reducing methane emissions from oil and gas wells, city streets, and homes and buildings.

Their work has real practical applications for reducing the emission of greenhouse gases, though he admits Human driven emissions are in many ways easier to pin down than those from natural sources.

Earthquakes and Water- the Earth’s Plumbing System

In the throes of the worst California drought in recent history rivers and streams across California had been flowing at record low level and some streams were completely dry. Then late August a magnitude 6.0 earthquakes hit the South Napa Valley and a funny thing happened; water began to flow again in some previously dry creaks, rivers and streams. For decades scientists have noted that there is a hydrogeologic response to earthquakes, but understanding of this response is still very limited. In the case of the South Napa Earthquake the flow of springs and groundwater to some streams appears to has increased. Scientists at the U.S. Geological Survey (USGS) predict that based on the experience in previous earthquakes the stream and sprig flows will decline again over the next several months if the rains do not return to California.

from USGS

Hydro-geologic responses to earthquakes have been observed to occur both in the area of the earthquake and thousands of miles from the earthquake epicenter. Earthquakes impact groundwater the most commonly observed impact is to water wells. Some well have been observed to become turbid or muddy, some have run dry or had an increase in flow or water level. New springs have formed and the quality of groundwater and surface water has changed. Some of these changes are transitory others appear to be permanent and only time can tell the difference between them. In addition, there have also been surface water responses to earthquakes. Surface-water responses to earthquakes include changes in chemistry, wave oscillations in lakes, increases and sometime decreases in stream, spring, and seep discharge, instances of springs going dry or the appearance of new springs.

According to the USGS the water-level fluctuates in wells in response to seismic waves. The occurrence and size of the water level response of water wells to earthquakes are influenced by a variety of factors such as the magnitude and depth of the earthquake, the distance of the well from the epicenter, the geology surrounding the well, the depth of the well, whether the aquifer is confined or unconfined and the well construction. The most common observed groundwater response to an earthquake is an instantaneous water level offset or step up. An instantaneous increase or decrease in water level. This response is commonly observed because there are hundreds of wells used to monitory water levels nationally. The change and recovery in water level can be so rapid that it is barely detectable, or it may take minutes, hours, days, or months for a well to return to previous water levels. There have also been instances where the well never returned to pre-earthquake levels.

Lots of things can impact the response of a well to a seismic event and scientists cannot predict which wells will be impacted and whether the impact is permanent or transitory. The USGS reports that within 3 months of the 1998 magnitude 5.2 earthquake in northwestern Pennsylvania that over a hundred private water wells in the area went permanently dry. The 2002 Alaskan Denali Fault earthquake which was a magnitude 7.9 caused a 2-foot water-level rise in a well in Wisconsin, more than a thousand miles from the epicenter. That rise also appears to be permanent.

From USGS

What is clear is that groundwater aquifers systems are mechanically connected to the rocks and sediments in which they exist. In addition to hydrogeologic responses to earthquakes, hydrogeologic changes may cause earthquakes or volcanic events. Earthquakes can be induced by the filling of surface reservoirs, or by annual or shorter-term fluctuations in reservoir levels. In addition, earthquakes can be induced by the deep well injection (or withdrawal) of fluids as has been seen in the disposals in the 1960’s at the Rocky Mountain Arsenal and more recently in disposal of the waste fracking fluid from hydraulic fracking.

The USGS says that water level offsets in the area of an earthquake because the earthquake “subjects the earth’s crust and its aquifer systems, to stress and permanent strain (deformation). This deformation process results in altered fluid pressure within the aquifer systems, and consequently, a step like change in water level would be expected.” The USGS cites various mechanisms for well water responses based on type of geology. For increased water level in shallow wells, the USGS suggests that compaction of overlying alluvium similar to liquefaction may be the mechanism producing the offset. Fluid-pressure declines are suggested to be caused by the escape of small amounts of dissolved gas from pore spaces in the aquifer in response to seismic waves. In a fractured rock system like the one here and in northwestern Pennsylvania where the wells went dry, permeability of the ground may be changed by the unclogging, widening, or narrowing of fractures, or the creation of new fractures. Similarly, an increase in ground-water discharge though springs, seeps, or to streams could be caused by an increase in the subsurface fluid pressure or permeability of the geologic formation.

There have also been several instances of reported changes in water levels in well before an earthquake. Many of these documented cases come from seismically active Japan where they continue to search for predictors of earthquakes. Many scientists do not believe that groundwater and well response can be used to predict earthquakes; they believe that there are too many other explanations for well water changes. Truthfully in the last couple of years (in my volunteer work with the VAMWON) I’ve seen several instance of what I think of as transitory benign well response where a well level falls dramatically and then recovers seemingly unconnected to precipitation and use. I have also seen transitory turbidity that just seems to pass through and then the well returns to normal. There are many potential explanations for these observations, so I simply note them and test the water quality when it returns to normal to make sure it is safe to drink.

However these episodes make you think about how interconnected the groundwater system is to the earth. Recently Dr. Robert Jackson et al. published an analysis of all the peer reviewed research done on hydraulic fracking. Though there has been documented impact to groundwater from improperly constructed wells, there has been no confirmed impact to groundwater from fracking itself. Rather than testing for direct chemical contamination in areas surrounding a hydraulic fracking maybe scientist should be looking for changes in water quality and quantity in nearby groundwater wells and systems that are more typical in seismic events.


For more information on stream flow and water well responses to earthquakes and discussion of potential mechanisms see research from Department of Earth and Planetary Science, University of California, at Berkeley by Chi-Yuen Wang, Michael Manga and others.

Natural Gas Leaks-Death and Climate Change

Yellow spikes are methane leaks measured in Boston. From Jackson et. al. 

Two recent studies have documented thousands of gas leaks in Boston and Washington D.C. Last year two scientists, Robert B. Jackson, Professor of Global Environmental Change at Duke University and Nathan Phillips, associate professor at Boston University Department of Earth and Environment collaborated with Robert Ackley of Gas Safety Inc., and Eric Crosson of Picarro Inc., to perform a study of gas leaks in Boston. They mapped the gas leaks under the city using a new, high-precision methane analyzer provided by Picarro installed in a GPS-equipped car. Driving all 785 road miles within city limits, the researchers discovered 3,356 leaks. The leaks were found to be associated with old cast-iron underground pipes, rather than neighborhood socioeconomic indicators. Levels of methane in the surface air on Boston’s streets exceeded 15 times the normal atmospheric background value. Cast iron is often the oldest and leakiest, especially at the joints, although other pipeline materials can also develop leaks.

This past spring, the team replicated the study on the streets of Washington, D.C. The results for the Washington D.C. study have not been published, but preliminary reports indicate that D.C., too, has thousands of leaks from its natural gas distribution system. According to a report in Scientific American, Dr. Jackson stated, the number of leaks per road mile is similar to that of Boston, but has almost twice as many miles of road.

For some time our infrastructure systems have failed to keep pace with the current and expanding needs, and investment in infrastructure had faltered as an unseen way to cut costs. Every four years the American Society of Civil Engineers, ASCE, grades the infrastructure in the United States, from water mains, sewer systems and plants, the electrical grid, the neighborhood streets and the national highway system, dams, rail roads, airports. Infrastructure is the foundation of our economy, connecting businesses, communities, and people, making us a first world country.

In 2013 the grade for energy remained at a D+ despite the boom in gas and oil due to weakness in the distribution systems. Though, the recent booms in oil and gas production could supply the energy demand, we have failed to maintain and upgrade the oil and gas. Gas distribution companies are well aware of the leaks in the system. The companies calculate the difference between the gas pumped into the distribution system and what is metered at the end user. This is referred to as "lost and unaccounted-for" gas is often a surcharge on customer bills. These leaks are wasteful, dangerous and a significant source of greenhouse gas released into the environment.

Distribution companies prioritize finding and fixing leaks likely to be explosion hazards, where gas is collecting and concentrating and ignore the small losses from deteriorating iron pipe. Though sometimes they do not do that well enough. Natural gas distribution leaks and explosions cause an average of 17 fatalities, 68 injuries, and $133 million in property damage each year, according to the U.S. Pipeline and Hazardous Materials Safety Administration. The transportation and distribution systems run into homes and businesses. In 2010 a natural gas pipeline exploded in San Bruno, CA, just south of San Francisco. There was no warning and eight people were killed, 58 were injured and 38 homes, the entire section of a neighborhood, destroyed. The deaths in San Bruno did not change the way we maintain our infrastructure, though the California Public Utilities Commission has proposed a $2.25 billion penalty, which includes a $300 million fine.

According to Dr. Jackson and Phillips detecting and reducing gas leaks are critical for reducing greenhouse gas emissions, improving air quality and consumer safety, and saving consumers money. In addition to the explosion hazard, natural gas also poses a major environmental threat: Methane, the primary ingredient of natural gas, is a powerful greenhouse gas that degrades air quality. Leaks in the United States are reported to contribute to $3 billion of lost and unaccounted for natural gas each year. Included in the details of the White House climate plan, originally introduced in a speech at Georgetown University in June, is an “interagency methane strategy” that examines the scope of leaks from gas wells, pipelines and compressor plants to examine their contribution to global warming.

The White House climate plan was released immediately after the International Energy Agency (IEA) released a series of recommendation for measures that might curtail the rapid growth that has occurred in carbon dioxide emission from fuel combustion that has taken place in the past few decades despite treaties, meetings and conferences. Global greenhouse gas emissions are increasing rapidly and, in May 2013, carbon-dioxide (CO2) levels in the atmosphere exceeded 400 parts per million for the first time in several hundred millennia.

Though mankind has blown through the tipping point in CO2 emissions that was just a decade ago referred to as the point of no return, the IEA is making policy recommendations that might hold the global temperature increase to 2 to 4°C by cutting global CO2 emissions growth so that it does not exceed 38.75 billion metric tonnes from fossil fuels in 2020. These recommendations really fall into two categories, efficiency and maintenance:

• Installing energy efficiency measures in buildings, and requiring increased efficiency in industry and transportation
• Preventing the construction of and limiting use of the least-efficient and dirtiest coal-fired power plants. In addition to increasing the share of power generation from renewable sources (including nuclear) and from natural gas
• Reducing methane released from the processing and distribution of oil and gas by replacing aging infrastructure and improving technology implementation.