Soil Carbon Sequestration and Biochar Technologies

The recognition that most IPCC scenarios for to avoid exceeding the 2°C “guardrail” require large-scale deployment of negative emissions technologies (NETs) has led to extensive recent discussion of the potential effectiveness and risks associated with a range of option. However, as the authors of a new study published in theBiochar journal Global Change Biology conclude, most studies to date have focused on bioenergy with carbon capture and sequestration (BECCS), direct air capture, enhanced weathering of minerals, and afforestation and reforestation. This study, by Pete Smith at the University of Aberdeen, expands the scope of inquiry to two other NETs options: 1. soil carbon sequestration (SCS), through methods such as alternation of agricultural practices, including no-till or low-till with residue management, organic amendment and fire management; and 2. Biochar, which is production of charcoal as soil amendment via the process of pyrolysis which can, inter alia, sequester carbon. Biochar, at least, is often included under the rubric of “climate geoengineering” options, in the subcategory of carbon dioxide removal (CDR) approaches.

Among the study’s findings:

  1. SCS at global scale could sequester from 0.4-0.7GtCeq. yr-1, with technical potential of 1.37GtCeq. yr-1, at a cost of ~$70-370 per ton of Ceq. Biochar could effectuate sequestration of ~1 GtCeq yr-1, with a maximum potential of 1.8 GtCeq yr-1
  2. By contrast, BECCS might be able to sequester 3.3 GtCeq yr-1 by 2100, and direct air capture a comparable amount. However, the potential of SCS and biochar are higher than either enhanced weathering and comparable to afforestation and deforestation;
  3. About 20% of the mitigation to be derived from SCS could occur at negative cost, and 80% between $0-40 tCeq. Biochar costs range from -$581-1560 billion;
  4. In terms of water requirements, SCS and biochar are virtually zero, while direct air capture has medium to high water demands, and BECCS creating “a very large water footprint;”
  5. In terms of energy requirements, SCS has a negligible energy impact, and biochar can actually produce energy during the pyrolysis process; by contrast, both direct air capture and enhancing mineral weathering have significant energy requirements;
  6. One significant issue in terms of both SCS and biochar is “sink saturation,” i.e. decreased carbon sequestration potential as soils approach a new, higher equilibrium level. This can occur after 10-100 years for SCS, and is also an issue for biochar. This has implications for deployment of these technologies, as most scenarios for use of NETs envision primary importance in the second half of this century, meaning that deployment of some approaches in the next few years might have little impact later this century.

Overall, the author of the study concludes that SCS and biochar should be given serious consideration in integrated assessment models given their advantages over some other NET approaches.

Among the classroom questions that this study might generate:

  1. How do we determine the optimal mix of R&D funding for NETs?
  2. What should be the most important criteria for determining if we proceed with research on individual NETs options?
  3. What kind of governance architecture should be established for NETs research and development and/or deployment?

Compendium of Commentary on the Paris Agreement/COP21

untitledThe purpose of this compendium, which will be continually updated, is to amass a compendium of online pieces that might be useful for getting a handle on the new agreement, as well as providing some potential student readings.

 

1. UN INSTITUTIONAL RESOURCES

2. NEGOTIATING HISTORY AND PROCESS

3. GENERAL CRITIQUES

4. CRITICAL CRITIQUES

5. FUTURE IMPLEMENTATION OF THE PARIS AGREEMENT

5.1  U.S. Implementation

5.2   Geoengineering

6. BUSINESS FOCUS

7. ENERGY SECTOR IMPLICATIONS

8. LEGAL ANALYSES

8.1 Loss and Damage

9. ROLE OF CARBON MARKETS

10. JUSTICE AND EQUITY CONSIDERATIONS

11. MULTI-MEDIA PRESENTATIONS

 

Lecture on Climate Geoengineering

earthwrenchI recently delivered a lecture at University of Wisconsin, entitled “Into the Great Wide Open: The Potential Promise and Peril of Climate Geoengineering.” It provides an overview of climate geoengineering options and potential avenues for governance. The video for the lecture, including the Power Point presentation, is available here.

Historical Carbon/Climate “Debts,” and Implications for State Responsibility

CaptureAs this blog is being penned, the Parties to the UNFCCC are convening in Paris for COP21. The cynosure of the meeting is the mandate “to develop a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties” to enhance climatic commitments. Thus, questions of fairness and equity in allocating emissions reductions and State responsibility are front and center. A new study by Damon Matthews in the journal Nature seeks to provide pertinent metrics to guide this inquiry. The study quantifies historical “carbon debts” of States, defined as the cumulative (since 1960) debt of countries whose emissions exceed an equal per capita share, and “climate debts,” defined as “the accumulated difference between actual temperature change caused by each country … and their per-capita share of global temperature.”

Among the findings and conclusions of the study:

  1. In terms of the “carbon debt,” the cumulative world debt (and “credit” for some countries) is 500 GtCO2 since 1960, and 250 GtCO2 since 1990. This translates into 40% of said emissions produced by countries in excess of levels consistent with their shares of world population;
    1. The United States is the leading “debtor” under these calculations, with the leading “creditors” being China and India, given historically low per-capita emissions. However, the landscape has changed more recently in terms of China, with its per capita emissions now pegged above the global average;
  2. In terms of so-called “climate debt,” the United States is responsible for 32% of the cumulative debt since 1960, with other significant debtor countries including Russia (10%), Brazil (9.8%), as well as Germany, Australia and Indonesia. Brazil and Indonesia’s debt is largely attributable to high levels of deforestation and methane and nitrous oxide emissions associated with the agricultural sector;
    1. Countries with the climate “credits” include India (35%), China (26%), Bangladesh (4.9%), Pakistan (4.3%) and Nigeria (2.4%)
    2. The total climate debt translates into 0.11C temperature increase form 1990-2013, or approximately a third of warming since 1990
  3. The decision as to whether to assess emissions based on territorial/production-based emissions or a consumption-based approach that allocates emissions associated with consumption of goods to consumer countries, can make a profound difference in the calculations of the “debt.” For example, China’s exported carbon debt is almost twice as large as its production-based value, and Russia’s transferred debt/credit is almost 35%. The same is true for large importers, such as Japan, Germany and the UK.

Among the class discussion questions that this article could raise are the following:

  • From an equity perspective, should a major product exporting country, e.g. China, be responsible for the emissions associated with said products when they are consumed in other countries? Does the fact that they derive profits from such production influence your answer?
  • The article suggests that we might wish to modify the per capita emissions metric for carbon debt to acknowledge differences in circumstances, e.g. cold temperatures. Do you think this would be a good idea, and if yes, what factors would you include and how would you weight them in the carbon debt equation?
  • The study pegs the respective carbon/climate debt and credits of countries based on emissions beginning in 1960. Would you establish a different baseline, and why?

Prospects for Averting Severe Climate Change at COP21?

For instructors discussing the prospects for “The Road to Paris” at COP21 to help us build a bridge to a safer climatic future, a new study in the journal Nature would be a good student reading. The study draws upon the Intended National Determined CoNaturentributions of the more than 150 countries that have made such pledges to date,embodying 90% of the globe’s emissions. The study’s authors seek to assess both the prospects for limiting temperature changes to 2C from pre-industrial levels, as well as how much such pledges reduce the risk of the highest potential increases in temperatures. The authors emphasize that because temperature changes ultimately depend on cumulative emissions, it’s critical to assess the likely long-term paths of emissions commitments beyond the INDCs, which extend to only 2025 or 2030. This was calculated through the use of a global integrated assessment model. Also, the uncertainties associated with the global carbon cycle and climate system responses necessitates probabilistic assessments. The study utilizes two scenarios, a Paris-Continued minimum (2% annual rate) scenario assuming that countries proceed to reduce emissions at the same rate as required to achieve their INDCs between 2020-2030, and a Paris-Increased ambition scenario, assuming a 5% annual reduction beyond 2030.

The study’s conclusions include the following:

  • The Paris-Continued scenario reduces the probability of temperatures increasing more than 4C in 2100 by 75% compared to the Reference-Low policy scenario, and by 80% from a Reference-No policy scenario;
    • The chance of exceeding 4C is virtually eliminated if mitigation efforts are increased beyond 2030, such as in the Paris-Increased ambition scenario
  • There is an 8% probability of limiting temperature increases to 2C from pre-industrial levels In the Paris-Continued ambition; this increases to about 30% under the Paris-Increased scenario.
    • Scenarios to increase the probability of limiting temperatures to 2C to between 50-66% are plausible, but assume rapid emissions reductions after 2030, and many also include negative global emissions in the second half of the century, effectuated through the deployment of Bio-energy Carbon Capture and Sequestration (BECCS).
  • To limit warming to any prescribed level in the future will necessitate ultimately reducing carbon dioxide emissions to zero. If this doesn’t transpire quickly beyond 2100, the prospects of both extreme temperature changes and exceeding the 2C threshold are substantially increased.

Polimp: Resources on European and International Climate Policy

For inPolimpstructors who include a discussion of European responses to climate change, including the EU-ETS, I would suggest checking out the resources on the Polimp site.  The site is funded by the European Commission under its 7th Framework Program.

Among the resources on the site pertinent to those teaching climate and energy courses are the following:

  • The Climate Policy Information Hub, a portal which provides concise summaries and links to additional resources on an array of climate policy and science issues, including European Union climate policy, international climate policy institutions, renewable energy policies, and detailed information about climate and energy issues in several key sectors, including residential, transportation and agriculture;
  • An archived webinar series, which includes an excellent recent discussion of the future of the EU-ETS, lessons learned from the 15th UNFCCC COP in Copenhagen for the upcoming 21st COP in Paris, and the contours of European climate policy for 2030;
  • A Policy Brief Series, which includes briefings on stakeholder perspectives on the EU-ETS, and financing renewable energy in the European Union,

The site also includes a (free) newsletter for apprising subscribers of new resources on the site and upcoming events.

New WMO Greenhouse Gas Bulletin

In its most recent GWMO Bullreenhouse Gas Bulletin, the World Meteorological Organization provides some of the most contemporaneous data on the status of long-lived greenhouse gases in the atmosphere, as well as providing some excellent charts for lectures and presentations on climate science.

Among the key findings in the publication:

  1. Radiative forcing by long-lived greenhouse gases increased by 36% between 1990 and 2014, with carbon dioxide accounting for approximately 80% of this increase;
  2. Carbon dioxide levels reached 143% of pre-industrial levels in 2014 and is responsible for 83% of the the increase in radiative forcing over the past decade. Global atmospheric concentrations reached 397.7ppm in 2014, with an average annual growth rate of 2.06ppm over the past decade, with last year’s growth rate over 2013 of 1.9ppm
    1. Approximately 44% of anthropogenic carbon dioxide emissions reached the atmosphere in the past decade, with the remaining 56% removed by oceans and the terrestrial biosphere
  3. Methane concentrations in the atmosphere reached 254% of pre-industrial levels in 2014, contributing 17% of the radiative forcing of long-lived greenhouse gases. Atmospheric concentrations were 1833 ppb in 2014;
  4. Nitrous oxide levels reached 327 ppb in 2014, up 21% above pre-industrial levels. Nitrous oxide accounts for 6% of radiative forcing by long-lived greenhouse gases;
  5. Chlorofluorocarbons and minor halogenated gases account for 12% of radiative forcing by long-lived greenhouse gases, though their production is declining due to international treaty regulation. While potent greenhouse gases hydrochlorofluorocarbons and hydrofluorcarbons are increasing in production at a substantial clip, their atmospheric concentrations remain low, in the parts per trillion currently.

The Bulletin also provides a concise explanation of the anthropogenic greenhouse effect, including an excellent chart explaining radiative forcing.

 

 

 

Mind the (Emissions) Gap

For instructors discussing the likely impacts of the emissions reductions commitments agreed to by the Parties to the UNFCCC under the Durban Platform for Enhanced Action (denominated “Intended National Determined Contributions” or “INDCs”), the just-released eight-page Executive Summary of UNEP’s Annual “Emissions Gap Report” would be an excellent reading. Other recent assessments of INDCs include the UNFCCC’s Synthesis Report on the Aggregate Effect of the Intended Nationally Determined Contributions, and studies by Climate Action Tracker and Climate InteractiveUntitled-1. The 2015 Report compares projected emission levels in 2030 (based on the INDCs of 114 States by October 1, 2015) with scientific assessments of emissions pathways consistent with keeping temperature increases below 2C from pre-industrial levels.

Among the study’s findings are:

  1. Based on the IPCC Fifth Assessment Report’s estimate of a remaining cumulative carbon dioxide emissions budget of 1000 GtCO2 (to avoid passing the 2C threshold), net global carbon emissions will have to be reduced to zero between 2060 and 2075;
  2. To have a greater than 66% chance of avoiding temperature increases above 2C by the end of century the median level of carbon dioxide equivalent emissions in 2030 should be 42 GtCO2e (range of 31-44), 39 GtCO2e to keep temperature increases to 1.5C.
    1. While the INDCs made by the Parties to the UNFCCC to date constitute “a real increase in the ambition level compared to a projection of current policies, the emissions gap between full implementation of unconditional INDCs and the least-cost emission level for a pathway to remain below 2C are estimated at 14 GtCO2e in 2030 and 7 GtCO2e in 2025. Conditional INDCs could reduce the gap to 5 GtCO2e in 2025 and 12 GtCO2e in 2030. This translates into a temperature increase of 3.5C by 2100 (66% chance)
    2. The global emissions levels in 2030 consistent with avoiding passing the 2C threshold is 42 GtCO2e in 2030, while project emissions from unconditional INDCs are projected to be 56 GtCO2e in 2030, or 45 GtCO2e when conditional INDCs are taken into account.
  3. Global greenhouse gas emissions could be reduced by an additional 5-12 GtCO2e below unconditional INDCs through measures such as enhanced energy efficiency, and International Cooperative Initiatives, such as efforts by cities and regions, sector specific initiatives (such as reducing cement-related initiatives), and forest-related initiatives, e.g. REDD+

The electronic version of the report also includes a number of charts and diagrams that would could be used in class lectures, including portrayals of historical GHG emissions and projections until 2050, the emissions gap of INDCs and requisite reductions in emissions to avoid passing critical temperature thresholds, and a map outlining the INDCs of UNFCCC Parties.

 

 

Special Issue on Climate Geoengineering Law

earthwrenchFor instructors interested in covering the topic of climate geoengineering in their courses, there is a new special issue on the topic of climate geoengineering law in the journal Climate Law. The special issue’s editors are Wil Burns & Simon Nicholson of the Forum on Climate Engineering Assessment.

Electronic reprints can be obtained of any of the pieces by contacting Wil Burns at: wil@feronia.org.