Rusting of Rivers in Alaska’s Brooks Range Likely Resulting from Iron Oxidation Thought to be Caused by Thawing Permafrost Exposing Bedrock and/or Thawing Wetlands Activating Iron-Rich Soil Bacteria

   Rivers in Alaska and the Yukon are turning orange due to iron oxidation. The source of this chemical alteration that is very similar to the formation of acid mine drainage is the thawing of permafrost and/or wetlands. That thawing is caused ultimately by global warming which has been significantly amplified in the Arctic as the following graphic shows. This is known as Arctic Acceleration.

Melting permafrost is thought to have several potential dangers, the biggest perhaps being the widespread release of methane that has been sequestered in the frozen ground and that if released can result in a feedback mechanism that could theoretically become a runaway feedback where that methane heats up the atmosphere even more and makes melting and methane release even more widespread. The rusting of rivers due to iron oxidation, however, was apparently not predicted.

     The issue is particularly problematic in Alaska’s Brooks Range which extends 700 miles from Alaska into Canada’s Yukon Territory. At least 75 rivers and streams have rusted in the region just over the last 5-10 years. The discoloration of the water is due to oxidizing iron and sulfuric acid, which means high concentrations of heavy metals are precipitating in the rivers. The oxidation of minerals in the soil may also be lowering the pH of the water, increasing its acidity. pH readings as low as 2.5 have been recorded which makes the issue equivalent to acid mine drainage from coal mines and some minerals mines. The level of dissolved metals as measured by electrical conductivity was roughly equivalent to that of industrial wastewater. The water is undrinkable by environmental standards. Many of the rivers before that had alkaline chemistry with pH above 7. There are obvious dangers to plant life, aquatic life, and fish in the rivers as toxic metals leach out and the rivers become strongly acidic.  

     In 2022 the USGS and National Park Service began an investigation to map out the rusting rivers' extents and to better understand and quantify the effects. Integration of geology, hydrology, and permafrost degradation are all involved in these chemical changes. They are also studying the biological effects. We know that acid mine drainage causes massive negative effects on aquatic organisms, and this is likely to be very similar in effect. There are some people who rely on the local rivers for fish that will also likely be affected. Some of the rivers are known for spawning salmon runs downstream. Researchers think that the phenomenon is also likely to occur in other places in the Canadian and Russian Arctic regions.

     There are two prevailing theories for the phenomenon. One is that the thawing permafrost is exposing bedrock resulting in the release of iron and sulfuric acid into the streams. The other is that soil bacteria, activated by thawing wetlands, are producing the soluble iron. The acidic rivers, like acid mine drainage, also carry high sediment loads due to the precipitating metals. This creates murky water that makes it harder for fish and other aquatic creatures to find food. Iron and aluminum dissolved in the water can also accumulate on fish gills, affecting respiration. As explained below, both ideas may be contributing.

     Kobuk Valley National Park has warmed by 2.4 degrees Celsius (4.32 degrees Fahrenheit) just since 2006. Researchers think about 40% of the permafrost within the park has been thawed. Biodiversity has already been severely restricted in some of these rivers and if the phenomenon continues it seems likely that many will become devoid of life like acid mine drainage infested rivers and streams. Researchers found evidence of thawing permafrost throughout the region with the unmistakable rotting vegetable smell where microbes digest the matter and emit CO2 and methane.

     The thaw of permafrost under a wetland leads to the chemical reduction of oxidized iron that becomes soluble in water. Then, when the reduced iron particles after transport via groundwater come into contact with sufficiently oxygenated waters, they can re-oxidize and precipitate out as rust. That is the basis of the thawing wetlands theory. It is supported by findings of characteristic gray soil under reducing conditions sampled below the once frozen ground.

     The very low pH water can cause acidic “burning” of vegetation which is depicted in some of the images below. The exposed bedrock or acid-rock drainage theory better explains the high acidity. Acid-rock drainage is known to occur when streams weather the sulfide rock associated with ore deposits. The phenomenon in the Brooks Range area had actually been occurring at much lower levels well into the past but has obviously been vastly accelerated by the thawing. The acid-rock theory assumes that the thawing permafrost is allowing oxygenated water to access pyrite-rich shale for the first time in thousands of years, forming sulfuric acid and oxidizing the reduced iron that would normally precipitate out as rust, to continue downstream. The region’s rocks also contain alkaline limestones that neutralize the acid which causes precipitation of the iron. Timothy Lyons, a geochemist at the University of California, Irvine said “It's like a one-two punch. You have the shaley rocks with pyrite that source the acid and the iron, and then the limestones neutralize that acid and cause the iron to come out of solution.” Researchers think other dangerous metals including copper, zinc, cadmium, lead, and even arsenic could be leaching out.

     The whole problem may continue and expand as more permafrost is melted. Beavers have also moved north, making more summer wetlands in the area, supporting the wetlands theory. It now seems likely that both processes, acid-rock drainage and soil bacteria are contributing to the increased soluble iron content of the waters.  

     Oddly perhaps, the natural rusting of the rivers has affected the remediation of waters from The Red Dog Creek mine, one of the world’s largest zinc mines. The mine is well downstream of the affected waters, but those upstream waters had been affecting the remediation system of waters exiting the mine. The area of the mine was already affected by acid-rock leaching so when remediation began the waters actually became cleaner than they had been before the mine was built. The water became less acidic, but the total dissolved solids (TDS) increased due to the sulfates and calcium hydroxide the mine was adding to the water to remove metals. Dissolved metals from upstream due to the thawing permafrost made TDS increase in the waters downstream that the remediation project was halted for a year while the mining company constructed a $19 million reverse osmosis plant to clean up the wastewater. The bottom line is perhaps that the permafrost has become a bigger polluter than the mine. According to the Scientific American article: “Lime is often dumped into tailings ponds at old mines to buffer acid, but you can't “lime” an entire mountain stream, just as you can't refreeze the ground around it. Perhaps the only real hope is that once all the permafrost has thawed and all the iron has rusted, these wild rivers will be able to flush out the contamination and restore themselves, although that would take decades at least.”

References:

75 Alaskan Rivers Turn Bright Orange, Tainting Water Supply, Endangering Humans and Wildlife; Scientists Investigate. Marissa Papanek. Knews. December 20, 2023. 75 Alaskan Rivers Turn Bright Orange, Tainting Water Supply, Endangering Humans and Wildlife; Scientists Investigate (msn.com)

Why Are Alaska’s Rivers Turning Orange? Alec Luhn. Scientific American. January 1, 2024. Why Are Alaska's Rivers Turning Orange? | Scientific American

The Rusting of Arctic Rivers: Freshwater Ecosystems Respond to Rapidly Uptaking Metals. US Geological Survey. Alaska Science Center. November 6, 2023. The Rusting of Arctic Rivers: Freshwater Ecosystems Respond to Rapidly Uptaking Metals | U.S. Geological Survey (usgs.gov)

Direct Air Capture of Methane? Is it in Our Future? Scientists Reveal Chemical Method that Consumes Methane 100 Million Times Faster Than Nature

     Researchers at the University of Copenhagen in Denmark have created a device that chemically consumes methane by reacting it with UV light and chlorine gas. The chlorine gas steals hydrogen ions from the methane to make hydrochloric acid which is captured and recycled, and “the methane atoms decompose into carbon dioxide (CO2), carbon monoxide (CO), and hydrogen (H2), the same way it is processed naturally but at a rate that's roughly 100 million times faster in the reaction chamber.” The method is promising where “waste air” near facilities such as wastewater treatment plants, livestock production, biogas production, and mine ventilation. I am guessing that some oil & gas facilities and operations could be included as well.

     Methane is commonly burned or flared to make it less potent as a greenhouse gas. The result of combustion is CO2 and water vapor. Flaring is common at landfills, upstream, midstream, and downstream oil & gas and petrochemical facilities, and at some coal mines. In order to be flared the methane concentration of the air needs to be about 4% or more. This system can dispose of those smaller concentrations of methane that cannot be flared. In nature, methane is mostly non-reactive. Thus, this method has the ability to make it reactive and consume it where flaring won’t work. The reaction chamber shown below in both model and actual forms is known as a Methane Eradication Photochemical System (MEPS).

Source: Scientists unveil methane munching monster, 100 million times faster than nature. Ameya Paleja. Interesting Engineering. December 19, 2023. Scientists unveil methane munching monster, 100 million times faster than nature (msn.com)

First methane gas collects in the reaction chamber. Then UV light is introduced to split the chlorine gas into individual chlorine atoms which are highly reactive. Those chlorine atoms then steal hydrogen atoms from the methane to yield hydrochloric acid. The methane atoms decompose into carbon monoxide (CO), CO2, and hydrogen.

Source: A high efficiency gas phase photoreactor for eradication of methane from low-concentration sources. Morten Krogsbøll, Hugo S. Russell, and Matthew S. Johnson. December 18, 2023. Environmental Research Letters, Volume 19, Number 1. A high efficiency gas phase photoreactor for eradication of methane from low-concentration sources - IOPscience

     When the research was published the researchers were able to dispose of 58% of the methane in the waste air but since then they have achieved 88% disposal. Thus far the technique has only been successful at laboratory scale. The next step is to scale up “to fit a 40-foot shipping container, which can then be connected to a ventilation system in a livestock barn, where much of the methane is produced.” Since at many higher-tech livestock farms, ammonia is already removed from the air. It is thought that adding methane removal is achievable at such facilities.

     For larger methane accumulations in waste air such as oil & gas and industrial sites, there are better methods to remove methane such as regenerative thermal oxidation (RTO), and catalytic thermal oxidation (CTO). According to the paper in Environmental Research Letters: “They operate by oxidizing pollution with heat, or by running the air stream over a catalyst bed at elevated temperatures. Due to the capital and operating costs, the RTO method is suited to high levels of VOCs including methane (above 0.1%–0.2%) in large air flows such as might be found in industrial settings [14]. Low-concentration methane sources can be treated but at prohibitively high cost and energy input. RTO will also produce NOx gases due to the high temperatures needed for effective methane removal. For CTO methods, the main costs are due to the increase in temperature and the size required for large air flows to gain the needed residence time over the catalyst [15]. For agricultural and wastewater treatment conditions working with flows at scales of >1 m3 s−1, these approaches would require unreasonably large systems. The minimum concentration for methane removal demonstrated in a laboratory for CTO is 200 ppm as reported by Gélin and Primet [15]. Industrial thermal and catalytic oxidisers typically have a high thermal efficiency, ca. 95% [16]. At a typical operating temperature of 1000 ∘C this implies a heat loss corresponding to a change in temperature of the airstream of 50 K. Taking the specific heat capacity of air ∼1 J (g K)−1 and the density of air ∼1.2 kg m−3, this means the specific power requirement is ∼60 kJ m−3. Thermal and catalytic oxidisers may not be suitable for some applications due to the need for addition of natural gas to keep the combustion bed hot, their cost, and the fact that they work best for stable pollution loads whereas many industrial processes are intermittent.”

     Oxidation of low-level methane emissions is an ongoing research problem. Thus far, none of these methods have been proven at scale “with an acceptable volumetric (kJ m−3) or specific (kJ kg−1) energy input.” This project utilizing chlorine radicals has proven to be cheaper and more energy-efficient than using hydroxide radicals. There are other advantages as well. The resulting hydrochloric acid (HCl) is recycled back into chlorine to lower costs and needs for disposal. The MEPS system was demonstrated at an air concentration of 50 ppm methane with a flow rate of 30 l min−1. This work has led to patents being filed.

Source: A high efficiency gas phase photoreactor for eradication of methane from low-concentration sources. Morten Krogsbøll, Hugo S. Russell, and Matthew S. Johnson. December 18, 2023. Environmental Research Letters, Volume 19, Number 1. A high efficiency gas phase photoreactor for eradication of methane from low-concentration sources - IOPscience

     The conclusions from the paper:

“MEPS, as described in this article, has been shown to effectively oxidize low-concentration methane in laboratory-scale experiments. Moreover, the process is easily controlled as the chlorine concentration and UV lights can be rapidly adjusted to match changes in pollution load. This technology is still under development and power efficiency is continually being improved, as described above. The technology is scalable and could eventually be deployed in a number of real-world scenarios. Further improvement in the chloride recycling system is also envisaged.”

 

“In the near future, the photoreactor will undergo field-testing at scale and once optimized, MEPS could be the first viable technology for direct oxidation of low-concentration point-source methane at scale. Perhaps with further improvements, MEPS would eventually be able to treat ambient concentrations of methane when used in combination with a CO2 DAC system.” (my emphasis)

My take is that this is an interesting development in methane mitigation via methane oxidation of low-concentration atmospheric methane. It should be interesting to see how it develops, how fast it can be deployed, whether it can be deployed economically, and whether it can actually make a dent in greenhouse gas reduction over say the next decade.  

References:

Scientists unveil methane munching monster, 100 million times faster than nature. Ameya Paleja. Interesting Engineering. December 19, 2023. Scientists unveil methane munching monster, 100 million times faster than nature (msn.com)

A high efficiency gas phase photoreactor for eradication of methane from low-concentration sources. Morten Krogsbøll, Hugo S. Russell, and Matthew S. Johnson. December 18, 2023. Environmental Research Letters, Volume 19, Number 1. A high efficiency gas phase photoreactor for eradication of methane from low-concentration sources - IOPscience

Coal Use Is at Record Levels: What is the Future of Coal? Peak Coal Supply and Peak Global GHG Emissions Soon, Peak Coal Demand Soon Thereafter

     2022 and 2023 are the biggest years for global coal consumption. The new IEA report on coal has some great graphs. Many show the great upheaval in coal consumption and coal prices through the first year of the Russian-Ukraine war. The economic slowdown in China has helped to lower prices back to normal faster. Coal export destinations changed considerably, especially from Russia where much less coal was exported to Europe and much more to China. The abstract of the report sums up the current coal situation: “Today, coal remains the largest energy source for electricity generation, steelmaking and cement production – maintaining a central role in the world economy. At the same time, coal is the largest source of man-made carbon dioxide (CO2) emissions, and curbing consumption is essential to meeting international climate targets.” The IEA predicts coal demand will peak by 2030. That means coal demand will remain high, possibly even higher than now, till 2030.

     While most developed countries are effectively reducing coal demand, many developing countries are holding steady or increasing coal demand. China alone has over 300 GW of coal-fired power plants in planning and construction. China also uses a massive amount of coal for industrial purposes. India is also a major coal consumer. Other countries building coal-fired power plants include Pakistan, Vietnam, Indonesia, and others. Germany was more or less forced (not really as they could have used nuclear) to open new lignite coal mines and keep coal plants running that were scheduled to be mothballed, in response to the loss of cheap Russian coal and natural gas.

     The IEA also predicts that global coal use is set to decline in 2024 and plateau through 2026 from today’s peak. One key unknown is the performance of hydropower. If hydropower declines due to droughts, particularly in China, it will be replaced by coal which could keep demand high. China produces about half of the world’s coal and consumes more than half of it.

     The high prices coal was sold for in 2021-2023 have led to better financial stability for coal producers. Declines in coal consumption in Europe and the U.S. are expected to offset increases in China and India to keep global consumption on a general plateau. Many developed countries are decreasing their thermal coal use. A few are increasing consumption. An example is Indonesia burning more coal in the process of ramped-up nickel production. Non-power thermal coal used for industries such as steel and cement and lignite coal use are expected to increase slightly by 2026. We should note that as in the case of Indonesia, China, and other Southeast Asian countries, a significant amount of coal is still being burned for the production of clean energy – solar panels, wind turbines, battery materials mining, etc.

     Met coal demand is likely to plateau, according to the report: “Metallurgical (met) coal, which includes coking coal (hard, medium, and semi-soft) and coal for pulverised coal injection (PCI) is a primary ingredient in steelmaking. Coke, which is generated from the heating of coking coal in a coke oven without oxygen, is also employed in the manufacture of carbides, ferroalloys and other chemical compounds.”

The graph below shows the profitability of thermal and met coal. 

     Chinese coal demand is driven mainly by thermal coal for power. IEA notes that coal quality mined in China in 2022-2023 has an average lower calorific value, a lower heating value, so that likely increased emissions per unit of coal burned. However, China is aiming for peak carbon emissions by 2030, so the push is strong for renewables, gas, nuclear, and other energy sources to replace thermal coal.

     China’s coal conversion sector continues to grow strongly. IEA explains it here as follows: “Coal conversion refers to the processes that use coal as a feedstock to obtain another commodity as the output (usually via coal gasification). Depending on the final product, it is typically classified as coal-to-liquids, coal-to-gas (SNG or synthetic natural gas) or coal-to-chemicals, with methanol playing an important role as a final product or as an intermediate product to produce olefins and other chemicals. For over a decade, coal conversion in China has been seen as a strategy to reduce foreign dependence, amid increasing oil and gas imports, and to monetise domestic coal assets – particularly those considered stranded due to quality or location – while promoting local jobs. On the flip side, these processes are generally energy inefficient, water- and CO2-intensive, and have very volatile economic profitability due to its dependence on oil and gas prices.” The graph below shows the typical end uses for gasified and liquified coal.

 

 

     Through 2026, IEA predicts India will drive global coal demand growth, as China’s economy remains somewhat constrained by lower growth. India expects between 19 GW and 27 GW of new coal capacity coming online before 2027. They also expect a 6% growth in non-power thermal coal capacity for industry.

 

 

     The U.S. is expected to continue retiring old coal-fired power plants. As the graph below depicts thermal coal generation is expected to drop from the current 148 GW (about 715 TWh) to about 112 GW (about 542 TWh) through 2026. That is nearly a 25% drop. Some of that will be replaced by renewables and some by natural gas. As the second graph below shows, U.S. coal production is likely to continue its downward trend.

 

 

     Coal consumption is expected to resume dropping in the EU after the unplanned rises due to energy costs associated with Russia’s invasion of Ukraine. 

     In some of the developed Pacific countries such as Australia, Japan, Taiwan, and South Korea, coal consumption continues to drop. Indonesia is expected to increase coal demand significantly in the near term, led by its rising nickel production. Much of that nickel will be used in EV batteries. Vietnam and Thailand are expected to have moderate increases in coal demand through 2026. Thailand burns lots of lignite coal for power generation. Pakistan, Bangladesh, and Sri Lanka are expected to have growing coal demand over this period.

     Global coal demand is expected to decline, especially after the unexpected increases due to the Russia-Ukraine war. It is unclear, however, how much it will decline.

 

 

     IEA suggests that coal supply has peaked in 2023 and will drop from here on out. However, that drop will likely be slight and look more like a plateau: “Global coal production is forecast to have risen by 1.8% in 2023, with continued growth in India, China and Indonesia more than offsetting declines in the United States and the European Union. Thus, 2023 marks another all-time high in global coal production, totalling 8741 Mt. Steam coal and lignite account for about 87% of global coal production and their growth in production accounts for similar share of the global production increase. Coking coal accounts for the balance, driven by strong growth in Mongolia.”  

 

     As the graph below shows, global coal trade volumes are expected to peak in 2023. In that sense, one could say that we are finally beginning a global decline in coal. By 2030 the global decline in coal should be well underway.

 

     China retained market advantages and was shielded from the temporary global coal shortage, in part by a large increase in imports from Russia.

 

 

First Peak Global Greenhouse Gas Emissions, then Peak Coal Demand, then Peak Oil Demand, and finally Peak Natural Gas Demand (At Least That Seems to be the Most Sensible Approach)

     The IEA predicted in their World Energy Outlook 2023 that carbon emissions would peak globally by 2025. An article reviewing the report by Carbon Brief’s Simon Evans and Verner Viisainen thinks we are at peak greenhouse gas emissions now in 2023. In any case, it seems that we are quite close to the peak. That means that from now or soon going forward we will be for the first time actually reducing emissions globally on a continuing trend. Since emissions reduction is the real metric and the real purpose of the energy transition, perhaps this should be celebrated. In terms of solving global warming, it’s just a drop in the bucket but perhaps we can salvage some real symbolic value. It also shows human effort at the global level can result in positive change. Peak emissions is a milestone that will be seen on graphs for years to come. The question remains: What will be the slope of the peak? Will it head steadily downward, plateau, or something in between? The IEA projections for coal use look like something in between and since those are a fair proxy for global emissions, those emissions may be between as well. Falling emissions is an important, though mainly symbolic, milestone. In any case, it’s all downhill from here! I think the next one might be renewables covering all demand growth. This has yet to occur.  It too is a mostly symbolic milestone. Going forward, both natural gas and renewables will replace coal. They will also grow to meet increasing power demand from electrification.

     The IEA report has coal peaking at or before 2030 and both oil & natural gas peaking in a few years after that in most scenarios. As I have noted before, I think the IEA can be too aspirational and not realistic in their predictions. I noted in their hydrogen predictions that they were overly bullish for hydrogen. They do offer a range in their forecasts by depicting different scenarios. I tend to favor the most pessimistic ones for oil and natural gas. I think natural gas demand will grow if prices are decent and will not peak as soon as they predict. Even from an emissions intensity perspective, the sequence should be coal, oil, then gas for peaking and phase-out. Natural gas is the lowest emissions hydrocarbon and should continue to replace higher-emitting hydrocarbons where applicable. There is room for quite a bit more of this. Domestic gas is better for emissions reduction than imported LNG, but LNG life cycle emissions continue to be improved. Peak oil demand depends on many factors including EV adoption, other electrification, diesel fuel replacement in industry, transport growth in developing countries, and general growth in agriculture, mining, and industry. CO2 emissions from industry are expected to peak around 2025 under the most conservative IEA scenario.

 

 

References:

 

Coal 2023: Analysis and forecast to 2026. International Energy Agency. December 2023. Coal 2023 - Analysis and forecast to 2026 (windows.net)

Analysis: Global CO2 emissions could peak as soon as 2023, IEA data reveals. Carbon Brief. October 26, 2023. Analysis: Global CO2 emissions could peak as soon as 2023, IEA data reveals - Carbon Brief

World Energy Outlook 2023. International Energy Agency. World Energy Outlook 2023 (windows.net)

Climate Sensitivity: Quantifying It is Likely the Best Way to Validate Climate Change Models but Estimates Still Vary Considerably

 

     Indeed, most estimates of climate sensitivity still vary about as much as they did in the late 1970s. There have been many scientific papers with estimates through the years and that variation has persisted. Not surprisingly, those climate scientists who say climate change is a crisis tend to come up with high climate sensitivity estimates and those who say it is not a crisis tend to come up with lower estimates.  

     Climate sensitivity is simply a measure of how much the Earth's surface will warm for a doubling in the atmospheric CO2 concentration. It is “the average change in global mean surface temperature in response to a radiative forcing, which drives a difference between Earth's incoming and outgoing energy.” As I have always said, if climate sensitivity is lower, we can go slower. If it is higher, we may be in more trouble than we know, or as Wikipedia explains: “If climate sensitivity turns out to be on the high side of scientific estimates, the Paris Agreement goal of limiting global warming to below 2 °C (3.6 °F) will be difficult to achieve.

     Climate sensitivity is predicted as two different measurements, one short-term and one longer-term. The reason for this is that it takes time for the global climate system to reach a “steady state” after an increase in CO2 atmospheric concentration. Transient climate response is the short-term measurement of the increase in global average temperature expected when the atmospheric CO2 concentration has doubled. Equilibrium climate sensitivity (ECS) refers to “the higher long-term increase in global average temperature expected to occur after the effects of a doubled CO2 concentration have had time to reach a steady state.” Climate sensitivity is calculated in three ways: 1) direct observations of temperature and levels of greenhouse gases, 2) indirectly estimated temperature and other measurements from the Earth's distant past, a kind of paleoclimatic reconstruction, and 3) computer modeling of climate. Only number one, direct observation, is free of potential bias and other sources of error. The imbalance of incoming and outgoing radiation to and from the Earth is known as radiative forcing and is expressed in units of Watts per square meter (W/m²). Thus, climate sensitivity is a measure of how much temperature change a specific amount of radiative forcing will cause. Radiative forcing is influenced by many factors and for this reason, climate sensitivity is also influenced by many factors. It should be noted that ECS, also known as “fast feedback” climate sensitivity, makes the assumption that ice sheets, vegetation, and long-lived GHGs are fixed. Ice sheets in particular are thought to exhibit “slow feedback.” That view has been challenged in a new paper by James Hansen. There is another metric, Earth system sensitivity (ESS) that refers to a more general and inclusive mechanism that includes the amplifying feedbacks of GHGs and ice sheets. Climate sensitivity is not specific to CO2 even though accurate prediction of climate sensitivity to CO2 is the main goal of the metric. Feedbacks and other possible influences must be considered as well. Comparison to paleoclimatic warming and cooling events and direct measure of the influences of CO2-spewing volcanic eruptions are some of the evidence considered in determining climate sensitivity.

     Earth system sensitivity is not always exactly the same. For instance, it can change in time relative to the number of aerosol particles in the atmosphere since those particles have a net cooling effect. One can mathematically cancel out factors that change the Earth’s overall sensitivity to arrive at climate sensitivity. Thus, climate sensitivity is considered to be a true measurement of how our climate system reacts to temperature with all other influences accounted for and subtracted out. Even so, the quantitative effects of different climate variables such as aerosol particles and clouds on climate sensitivity are still hotly debated. For aerosols, this is important because aerosols are still being emitted into the atmosphere, mainly from coal and wood combustion and wildfires. Despite aspirations and plans to phase out coal globally, 2022 and 2023 have been record coal production years. While pollution abatement at coal plants has led to lower aerosol emissions, that number is still very significant. Climate scientists like Jim Hansen often point out that as coal burning is phased out, the cooling effect of the aerosols will also phase out. One could also say that burning wood, coal, and to a lesser extent oil is a form of geoengineering. Thus, we already have been monkeying around with our climate by artificially cooling it. Even so, experiments that had planned to release sulfate aerosol particles into the stratosphere to counter global warming have been canceled on grounds of fear of unknown consequences. The same is generally true of plans to fertilize the ocean so that it can take up more carbon.

 

Image credit: NASA; "The relentless rise of carbon dioxide"

 

 

     The target number we hear about, usually 1.5 degrees C or 2.0 degrees C, refers to the global mean surface temperature (GMST). That is a statistical average of many daily readings throughout the globe. This number is not in dispute. One thing its measure through time has shown quite conclusively is that warming is accelerated along the poles, most particularly in the Arctic. This Arctic Acceleration as it is dubbed is certainly a cause for concern. The graph below from NASA depicts it.

 

 

     Indeed, one of the biggest uncertainties about climate change is climate sensitivity. The range of sensitivity put forth by climate scientists has not budged much, if at all since the 1970s, from about 1.5 deg C to 4.5 deg C. Others have pegged the range from 1.8 deg C to 5.6 deg C and others yet have sought to put it between 2.1 deg C and 3.6 deg C. Two NASA climate scientists, John Christy and Roy Spencer, published a recent paper about their new one-dimensional climate model that shows climate sensitivity near the lowest end of the range at 1.9 degrees C. Other NASA scientists have recently ranged climate sensitivity between 2.6 degrees C and 3.9 degrees C. Christy and Spencer claim their model is better because it accounts for heat storage in deeper layers of land which other models do not incorporate. I do not know how valid this point is. There are many studies of climate sensitivity that have come up with values across the range. Other climate scientists that are climate skeptics like Richard Lindzen have also argued that climate sensitivity is at the low end of the range.

     Below the light blue section shows the current IPCC range of 2-4.5 degrees C for climate sensitivity and estimates from different lines of evidence. 

     

Source: How sensitive is our climate? Skeptical Science. How sensitive is our climate? (skepticalscience.com)

     Climate scientists who are climate advocates have tended to find values closer to the higher end of the range. James Hansen is the lead author of a May 2023 paper from Columbia University - Global warming in the pipeline – which argues predictably for a more alarmist conclusion based on global climate models (GCMs). The IPCC estimates ECS at 3.0 degrees C. The Hansen paper concludes that ECS is “near 4°C or higher.” In 2008, he accepted 3 degrees C as fast feedback ECS but pegged slow feedback ESS at 6 degrees C. Thus, we have two groups of climate scientists (Christy & Spencer and Hansen et al), both groups likely biased in their own ways, predicting climate sensitivity where one prediction is more than double the other(1.9 vs. 4.0 or more). Climate sensitivity is an assumption that is readily plugged into GCMs, and results will be drastically different for each group. Hansen et al predict that we will exceed 1.5 degrees C for GMST by 2030 and 2.0 degrees C by 2050. I should point out that Hansen’s predictions in the 1980s of the global response to CO2 forcings turned out to be significantly overestimated. Uncertainties in aerosol forcing quantification and climate response times in particular make climate sensitivity difficult to pin down except to confine it to a range, which has been done in the past. Hansen’s paper utilizes oxygen isotope analysis from the Cenozoic Era, which began about 66 million years ago, to try and pin down temperature responses to CO2 forcings and compare them to today. During the Cenozoic, atmospheric CO2 levels rode from 300 ppm to 400 ppm, which resulted in a nearly ice-free planet. However, any paleoclimatic studies, while quite useful, are difficult to get quantified effects. The continents were at different positions on the earth due to plate tectonics and ice sheet changes likely occurred at different rates as a result. In any case, Hansen et al argue that ESS may be a better measure because greenhouse gas feedbacks that amplify effects and ice sheets do not have the previously assumed slow response, but faster response times. They use the Cenozoic paleoclimatic analogy for this argument. The argument is essentially that if those feedbacks have faster response times than previously predicted as they suggest, then climate sensitivity is higher. They also note that the aerosol cooling effect will likely wear off as less coal and wood are burned so that too will speed up global warming in time. The aerosol effects from wildfires will likely continue. They argue that along with slow and fast feedbacks, there are ultrafast feedbacks that may not be properly accounted. While I am not sure about aerosol effects, the numbers from the graph below from Hansen’s paper seem to give aerosols a pretty strong cooling effect. He calls it a Faustian Bargain that we are enjoying with the cooling effects of aerosols. 

 

Source: Hansen et al  2023.

 

References:

Climate Sensitivity. Wikipedia. Climate sensitivity - Wikipedia

Anthropogenic aerosol drives uncertainty in future climate mitigation efforts. E. J. L. Larson and R. W. Portmann. Scientific Reports. 2019; 9: 16538. November 12, 2019. Anthropogenic aerosol drives uncertainty in future climate mitigation efforts - PMC (nih.gov)

Climate model provides data-driven answer to major goal of climate research. Dr. Roy W. Spencer, University of Alabama in Huntsville. Phys.org. September 29, 2023. Climate model provides data-driven answer to major goal of climate research (phys.org)

Global warming in the pipeline. James E. Hansen, Makiko Sato, Leon Simons, Larissa S. Nazarenko, Isabelle Sangha, Karina von Schuckmann, Norman G. Loeb, Matthew B. Osman, Qinjian Jin, Pushker Kharecha, George Tselioudis, Eunbi Jeong, Andrew Lacis, Reto Ruedy, Gary Russell, Junji Cao, and Jing Li. Columbia University. May 19, 2023. PipelinePaper.2023.05.19.pdf (columbia.edu)

Making Sense of ‘Climate Sensitivity': New Study Narrows the Range of Uncertainty in Future Climate Projections. Alan Buis, NASA's Jet Propulsion Laboratory. September 8, 2020. Making Sense of ‘Climate Sensitivity' – Climate Change: Vital Signs of the Planet (nasa.gov)

How sensitive is our climate? Skeptical Science. How sensitive is our climate? (skepticalscience.com)

 

 

 

COP28: What Does the Agreement to Transition Away from Fossil Fuels Actually Mean? And More from the Meeting

 

     What does the COP 28 agreement to transition away from fossil fuels actually mean? Well, that depends on who is asked. The rule is non-binding so it likely won’t be enforced, even though some, like Carbon Tracker founder Mark Campanale, think new coal and oil & gas projects will face lawsuits. Among anti-fossil fuel activists, many are putting forth the same tired old arguments. Anti-fossil fuel activist and climate scientist Michael Mann thinks developing countries should “leapfrog” from inadequate energy to clean energy. Biden climate envoy John Kerry has said the same in the past. Stanford anti-fossil fuel academic and atmospheric physicist Mark Jacobson, like many others, is saying that fossil fuel companies want to capture carbon and reduce their emissions by other means as well just to stay in business. Of course, this is true. Why would any business not want to stay profitable and relevant? Basically, their argument is that by not actively oppressing or banning fossil fuel projects they are able to maintain their profitability. Others often say that clean energy solutions to replace them are readily available at an acceptable price. The market generally disagrees, even with increased subsidization. The market favors profitability and fossil fuels are more profitable than clean energy. Fossil fuels are also more versatile so replacing them is not easy and includes not only clean energy generation but storage and transmission upgrades, both at significant and expensive levels.

     Since wind, solar, and other low-carbon energy sources have yet to fully supply demand growth, they have yet to even begin to ‘replace’ fossil fuels. Instead, they are covering most of the demand growth. But, since global energy use is still growing, that means fossil fuel use is also still growing. When renewables take over that demand growth, they begin to replace fossil fuels.

     The clean energy sector has been facing sustained financial pressure from inflation with projects being canceled and metrics like levelized costs of electricity rising. Supply chain issues continue to slow down solar and wind deployment. Transmission and storage inadequacies also continue to slow deployment. Capacity auction terms, capacity payments, and other issues can favor or disfavor renewables. Most now, I believe, do favor renewables. Capacity payments favor baseload energy sources and storage. The point is that variable generation renewables are accommodated as much as possible onto power grids, while full integration takes time, money, more transmission more storage, and more demand response from fossil sources.

 

 

COP28 Results

 

     Despite the failure to fully condemn fossil fuels, it seems that most are viewing the results of COP28 positively. The non-binding statement on transitioning away from fossil fuels is seen by many as a triumph, but by some as a mere aspiration. Oil & gas guru Daniel Yergin often referred to IEA goals as aspirational. Obviously, many net-zero goals are indeed aspirational. Are global carbon emissions peaking? The data suggest they pretty much are, but it is unknown when they will begin to drop. They could plateau for a while. Forecasts for the peaking of fossil fuel use generally range from 2030-2040. Optimists say 2030. Realists suggest 2035 or later.

     Over 100,000 people attended COP28 and there were more fossil lobbyists than usual. They were still far outnumbered by climate activists. Indeed, the increasing attendance of fossil fuel companies and the venue in the UAE presided over by a leader of a state oil company was cause for complaint by many activists. However, it is the Big Oil companies that now have significant renewable energy ventures, methane emission reduction protocols, and carbon capture and storage projects. They are among the biggest private funders of decarbonization.

     The statement called for “transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner, accelerating action in this critical decade, so as to achieve net zero by 2050”. Wood MacKenzie reported that “With the window closing fast, the focus in international negotiations is increasingly shifting to emphasise adaptation to climate change. But the “UAE consensus” is a signal that the pressure to shift the global energy system away from fossil fuels will continue.” I think it is good that adaptation is being given more emphasis. They also noted that while a phase-out of unabated fossil fuels by 2050 is possible, it will require consistently doubling energy demand growth with renewables. We have yet to meet demand growth with renewables, let alone double it.

     Another goal from COP28 is to triple renewables deployment by 2030. That may be feasible since renewables deployment was quadrupled from 2015-2023. Dropping inflation, better supply chain management, and increased transmission and other infrastructure would help. Will we be able to meet energy transition metals demand after 2030? WoodMac suggests that it depends on how fast we decarbonize.

     Focus on nature-based solutions for carbon offsetting continues to grow as a way for nations to contribute to emissions reduction. Unfortunately, carbon offsetting can be  difficult to quantify and verify and has been disputed by auditors in the past.

     Focus on adaptation is good. A $725 million Loss and Damage Fund, launched at COP27, has now been financed to help affected countries but many say that won’t be enough.

     A voluntary commitment to achieve net-zero emissions by 2050 was agreed by oil & gas majors with goals to eliminate routine flaring and reduce methane emissions. According to WoodMac:

 

“The Oil and Gas Decarbonisation Charter (OGDC) is a voluntary commitment to net-zero oil and gas operations by 2050. It was signed initially by fifty leading companies:27 NOCs, 17 Independents, and six out of seven Majors. Chevron, the only Major without a comprehensive corporate net-zero target, opted out. The signatories pledged to eliminate routine flaring and deliver near-zero methane emissions by the end of the decade.”

 

I would still caution that any mandates for emissions reductions need to be achievable and not overly expensive. There is room, I think, for some reasonable mandates, but I think voluntary reductions should be emphasized.

     EQT CEO Toby Rice delivered his steady message of unleashing LNG, particularly U.S. LNG, to reduce emissions relative to coal. This has been the best means to decarbonize in terms of actual emissions and this should continue and grow.

     Utility Dive summarizes other features of the COP28 document as follows:

 

“The document also calls for countries to adopt other decarbonization strategies to better mitigate climate risk. The agreement includes recommendations of phasing down unabated coal power; phasing out inefficient fossil fuel subsidies; ramping up production of zero- and low-emission technologies like carbon capture and storage; and switching over to zero- and low-carbon fuels.”

 

Fossil fuel companies and groups like OPEC helped to derail any binding agreement that would “hinder the continued production and use of oil, gas and coal, urging them to “proactively reject any text or formula that targets energy i.e. fossil fuels rather than emissions.”

 

     Unlike climate activists, I believe that these meetings will be more realistic and have more legitimacy when more fossil fuel companies and groups are included. Fossil fuel abatement will clearly be a big part of emissions reduction going forward as will carbon offsetting, reforestation, slowing deforestation, and renewables deployment.  

 

 

 

References:

 

COP28 key takeaways: The challenges in accelerating the energy transition. Wood MacKenzie. December 14, 2023. COP28 key takeaways | | Wood Mackenzie

 

Landmark COP28 agreement calls for ‘transitioning away’ from fossil fuels. Zoya Mirza. Utility Dive. December 13, 2023. Landmark COP28 agreement calls for ‘transitioning away’ from fossil fuels | Utility Dive

 

OPEC head urges members to reject fossil fuel phase out proposal at COP28. Zoya Mirza. Utility Dive. December 11, 2023. OPEC head urges members to reject fossil fuel phase out proposal at COP28 | ESG Dive