As 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?

For instructors 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.

For 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: [email protected].

Instructors who include a module on climate geoengineering may wish to include a section on a carbon dioxide removal scheme called “biochar.” Biochar is charcoal produced by medium- or high- temperature heating of biomass with little or no oxygen to drive off volatile gasses (a process called pyrolysis), leaving a more stable carbon, called char, behind. Biochar is touted as a potential “negative carbon” process, because it can sequester up to 40% of the total carbon from the biomass for centuries. Moreover, biochar is an excellent soil amendment, because it’s very effective at retaining both water and water-soluble nutrients, can reduce fertilizer requirements. Moreover, the pyrolysis process produces bio-oils with fuel value that is generally 50 – 70% that of petroleum bases fuels and can be used as boiler fuel or upgraded to renewable transportation fuels. However, some commentators have expressed serious concern that a large-scale biochar program would result in “land grabs” for biochar feedstocks that could threaten the interests of vulnerable populations, as well as adverse environmental impacts associated with land clearance under some scenarios.

A study from a few years ago by Woolf et al. in the journal Nature Communications would be an excellent reading for students because it focuses on the trade-offs between biochar production and other environmental considerations that can stimulate student discussion about broader considerations of the balancing of interests in the climate policy making realm. Through a series of scenarios, the study seeks to the maximum amount of biochar that can be produced sustainably or “maximum sustainable technical potential” (MSTP). The MTSP is defined as “the portion of the global biomass resource that can be harvested … without endangering food security, habitat, or soil conservation” when converted to biochar.

Among the conclusions of the study:

1. Sustainable global implementation of biochar could offset a maximum of 12% of current carbon dioxide equivalent emissions, with a total estimate of 130 Pg CO2-Ce over the course of a century
   1. By contrast, conversion of all sustainably obtained biomass to bioenergy could only offset 10% of current anthropogenic emissions. The advantage of biochar over bioenergy is greatest in areas where biomass crops would be grow in poor soils, while biomass combustion is a superior strategy for climate mitigation in areas with fertile soils, where biomass energy production is optional to offset coal combustion.
2. Use of land clearance strategies to produce biomass feedstock can result in “unacceptably high” carbon-payback times, e.g. 10 years for conversion of temperate grasslands, 50 years for clearance of rainforests, and an astounding 325 years for clearance of rainforest on peatlands;
3. Half of avoided emissions associated with biochar production would constitute sequestration of carbon dioxide, 30% from energy production that could displace fossil fuels, and 30 from avoided methane and nitrous oxide emissions;
4. Simultaneous large-scale production of bioenergy and biochar are not feasible.

Some of the class discussion questions that might be pertinent to this reading:

• Is it realistic to assume that a ramped-up biochar program would avoid unsustainable practices in the manner contemplated in this study?
• Is it appropriate to classify biochar as a “climate geoengineering” approach. Why or why not?;
• What would be the appropriate level of funding for biochar research programs given its mitigation potential?

Recent research indicates that the world needs to limit cumulative carbon dioxide emissions to approximately 1100 gigatons (with the IPCC suggesting a range of 870-1,240 Gt CO2) of carbon between 2011-2050 to have a 50% chance of keeping warming below 2°C from Pre-Industrial levels. However, as the authors of a new study in the journal Nature concluded, “the unabated use of all current fossil fuel reserves is incompatible with a warming limit of 2°C.” Indeed, the carbon dioxide that could be emitted by the current estimate of global fossil fuel reserves would exceed this critical threshold by three times (approximately 2900 Gt CO2). The study utilized a single integrated assessment model to assess the ramifications of the use of various fossil fuel resources in terms of their respective locations, type, and quantities. Its overall finding was that a third of global oil reserves, 50% of gas reserves, and over 80% of coal reserves need to stay in the ground to have a reasonable chance of avoiding passing the 2°C threshold.

Among the study’s other findings:

1. 82% of coal reserves would have to remain unburned under the study’s scenarios, with the United States and Former Soviet countries each pulling out less than 10% of their current reserves from the ground, leaving 200 billion tons unburned;
   1. Without CCS, bitumen production in Canada must cease by 2040;
   2. Even deployment of CCS within projected time frames and level of utilization does very little to change this number, permitting only 6% more to be utilized, and increasing oil and gas utilization by approximately 2%.
2. Gas plays an important role in displacing coal, including over 50 trillion cubic meters of unconventional gas production globally, half of which comes from North America. However, China, India, Africa and the Middle East would not fair so well, with over 80% unburnable by 2050;
3. None of the 100 billion barrels of oil and 35 trillion cubic meters of gas in fields within the Arctic Circle not being produced in 2010 can be produced in the 2°C scenario before 2050.

This would be an excellent student reading for any lecture that discusses solutions or efforts to establish priorities in terms of the future global energy mix. Its extensive coverage of the implications of CCS deployment would be helpful for coverage of that topic.

Among the possible questions for classroom discussion would be the following:

1. Would considerations of equity, including the principle of common but differentiated responsibilities suggest that the future mix should be re-jiggered some way?
2. What policy measures might be (practically) put in place to effectuate the prioritization of fossil fuel utilization outlined in the article?

For instructors who include a module on climate geoengineering, an excellent short reading on carbon dioxide removal approaches, and the challenges of effectively implementing them, is an article (subscription required) from last year by Sabine Fuss, et al., in the journal Nature Climate Change. As Fuss, et al. note, most emissions pathway scenarios that lead to atmospheric CO2 concentrations consistent with avoidance of temperatures above 2°C from pre-industrial levels contemplate some use of global net negative approaches in the second half of this century. In this study, the authors assess the prospects for the so-called “negative emissions” option most highly touted by the Intergovernmental Panel on Climate Change in its Fifth Assessment Report, Bioenergy with Carbon Capture and Storage (BECCS).
Among the findings of the authors are the following:

1. Many integrated assessment models (IAMs) contemplate carbon dioxide absorption by BECCS of 1,000 GtCO2 or more; this could effectively double the globe’s carbon “budget;”
2. Global net negative emissions strategies would have to be in place by 2070 for the most aggressive emissions scenarios. If deployment is delayed until substantial climate change has occurred, the response of the global carbon cycle will necessitate a larger program. Thus “the future option space depends strongly on today’s decisions;”
3. Challenges for deployment of BECCS include physical constraints associated with alternative land biomass and biomass needs (including agricultural demands and biodiversity conservation), response of terrestrial and ocean sinks to negative emissions, costs of speculative technologies and socio-institutional barriers, including public acceptance of new technologies;
4. In IAM scenarios consistent with keeping temperatures below 2°C from pre-industrial levels, BECCS approaches would have to sequester between 2-10 GtCO2 by 2050 (about 5-25% of 2010 CO2 emissions), and 4-22% of 2050 baseline emissions, which would entail “huge upscaling efforts,” especially in light of the currently challenging environment to develop large-scale CCS projects. This challenge is particularly imposing given the high costs of such projects and the low cost of emissions that are likely to be perpetuated absent the imposition of a meaningful price on carbon through climate policies;
5. While negative emissions options are, ostensibly, more expensive than other mitigation options, in the longer term, alternative mitigation pathways to 2100 are all substantially more costly without use of such technologies;
6. BECCS could serve as an alternative in the absence of a global accord to substantially reduce emissions for those countries lacking either capacity or the will to participate in international regimes.

Among the discussion questions that this piece might suggest:

1. How would we (can we?) reconcile the trade-offs between food production and energy production that, as the article suggests, BECCS might pose?;
2. While the article focuses on the viability of CO2 sequestration, what are the challenges, if any, of transport and storage of 2-10 GtCO2 annually?;
3. Are there tradeooffs associated with devoting substantial amounts of research and development funding to carbon dioxide programs? If yes, how does society, assess such trade-offs?