Hey, IPCC, over here!
Beyond the fodder the report provides for our rambling, this reports gives hard, bankable data that should refocus of discussion at all the meetings leading up to COP in Mexico in December. To the US Government’s credit, several committees have taken up this issue and are contemplating solutions.
The report is uninspiringly called Black Carbon, Emissions in Asia: Sources, Impact, and Abatement Opportunities.
The content, however, should be the topic of urgent conversations for the global climate change movement.
The Report’s Meat & Potatoes
These are the findings we want to highlight from the Executive Summary:
The reason the South Asian ABC is important is because a) it has a much worse greenhouse effect than CO2 in terms of regional impact on climate change, b) it disrupts the monsoon season in Asia, which causes food insecurity in the region, and, c) it contributes substantially to the accelerated melting of Arctic sea ice and glaciers. This is important but not surprising.
But, get this:
2. Open biomass burning in the form of forest fires, land clearing through fire, and burning of agricultural wastes is also responsible for large quantities of black carbon emissions. However, unlike contained combustion, open combustion also generates a relatively larger fraction of co-emitted organic matter that produces a climate cooling effect, thus counteracting the warming caused by the emissions of black carbon from these sources. Most studies estimate that open combustion has a neutral or negative overall global warming impact, although several studies do suggest that it contributes to climate warming. In any case, open biomass burning in Asia does have important negative impacts on the regional climate and on human health. China, India and the rest of Asia contribute roughly similar quantities to black carbon emissions from open combustion.
What I find interesting about this statement is that it somewhat debunks the stereotype of the burning of the Amazon (or Indonesian) forest as a major cause of Global Warming. In all fairness, it’s important to point out that the disappearance of the forest as carbon sink IS a serious matter and is not factored into the equation. Let alone loss of biodiversity, watershed, and other ecosystem services. But, still, the fact that CO2 emissions could be cancelled out by the emissions of cooling particles is a chink in the stereotypes armor. Let’s be clear, though, this should not be seen as a green light to torch the forest. If anything, it is instead a call to revise our stereotypes and question our assumptions.
The Case for the Low Hanging Fruit of Climate Change
The final finding is, for me, the kicker and it has to do with the cost benefit of the different black carbon emission reduction strategies.
3. Overall, changes in particle emissions from the household sector in developing Asia are thought to offer the largest potential for reducing near-term global climate impacts from short-lived global warming pollutants.
At the top of this hierarchy sit household fuel and stove interventions, which, if effectively implemented, appear to consistently achieve the highest reduction in black carbon emissions per unit cost. This finding holds true for all stove and fuel interventions examined for this study. Moreover, these interventions are cost-effective not only for control of black carbon, but also more broadly for abatement of global warming.
Not only is this finding very clear in the cost-benefit of large-scale programs that promote the adoption of clean cookstoves, but it also helps debunk the Africa stereotype, where people are perceived as being so poor that their impact on climate change is nil. This statement is of course true if you compare relative CO2 emissions, not black carbon. Why? Because more than 90 percent of sub-Saharan Africa depends on biomass as their primary fuel. Here’s a nice pie chart that speaks for itself.
If I read this graph correctly, inefficient household combustion outside Asia, China, and India accounts for a significant chunk of global black carbon emissions. Add slash and burn and the burning of ag waste and you’ve got more than half the pie chart covered by Africa and Latin America’s black carbon emissions. I’m pretty sure North America and Europe figure minimally in their contributions.
Why black carbon abatement is not one of the central topics of discussion by the climate change movement is a mystery to me given the findings in this report.
Let’s hope that the new IPCC director will see fit to add black carbon abatement to the current climate change negotiations.
* Black carbon in soot is the dominant anthropogenic absorber of incident solar radiation in the atmosphere – it is approximately 1 million times stronger than CO2 per mass unit of mass – and contributes to the warming of the atmosphere at the global level. Black carbon also warms the atmosphere by absorbing thermal infrared radiation from the ground and within clouds. Furthermore, because it directly heats surfaces on which it is deposited and changes surface albedo (surface reflectivity), black carbon is a major contributor to the accelerated melting of Arctic sea and land ice, glaciers and seasonal snow covers. However, black carbon has a much shorter average atmospheric residence time than CO2 and other GHGs (on the order of days to weeks for black carbon versus years to centuries for most GHGs). Because of this mediating factor, the combined global warming impact of one kilogram of black carbon via the multiple warming pathways is estimated to be on average 500-680 times as large as that of one kilogram of CO2 over a 100-year timeframe, and 1,500-2,200 times over a 20-year timeframe. Recent studies identify black carbon as the second- or third-largest overall contributor to current anthropogenic global warming, surpassed only by carbon dioxide and possibly methane.