A recent op-ed in the Asian Wall St. Journal raised some provocative questions about the allocation of responsibility for addressing climate change after the expiration of the Kyoto Protocol in 2012. While some might view the author's arguments as another effort to shift blame away from the US, EU and Japan, which together account for something like 60% of cumulative estimated emissions since industrialization, they highlight the challenges of dealing with this truly global problem in a world that is so inter-connected, and where economic activity no longer neatly aligns with national borders. This is a further indication of how difficult the essential task of crafting a successor to Kyoto is likely to be.
It's not unusual for advocates of an urgent response to climate change to treat such questions of international and inter-generational environmental equity as though the solutions were glaringly obvious. Yet when I assess the conflicting considerations involved, they look anything but simple. Because most greenhouse gases persist in the atmosphere for decades, with a few of them lasting thousands of years, historical emissions will affect the climate for many years and are thus clearly relevant to any allocation of responsibility for mitigating emissions. But emissions alone don't tell the whole story, without including widespread changes in land use that have altered the earth's ability to absorb both natural and man-made emissions. Including this factor for the period from 1950-2000 puts developing countries into a virtual tie with the industrialized nations in term of overall climate impact.
Nor does the inclusion of land-use changes resolve all questions of equity concerning historical emissions. Today's scientific consensus on anthropogenic climate change--widely but still not universally accepted--did not exist prior to the 1980s, and apportioning blame for emissions that predate that consensus seems unproductive. Holding current Americans and Europeans responsible for the consequences of emissions that were generated prior to the signing of the UN Framework Convention on Climate Change in Rio in 1992 seems at least as unfair as asking Chinese and Indians to take as much responsibility for their current and future emissions as developed countries must. While some might see a parallel to the duplicitous arguments of tobacco companies that knew for decades that their products were dangerous, the global warming theories of Arrhenius a century ago hardly count as a "smoking gun." There's legitimate disagreement about the point at which we should have known that fossil fuels and other activities were affecting the climate, but it was certainly no earlier than the last two decades.
Then there's the problem of offshored emissions. With a considerable share of the emissions from Asia's rapid industrialization attributable to products made for export markets in Europe and the US, who should bear responsibility for the CO2 and other greenhouse gases emitted along the way? Producers, who are often making slimmer margins than the retailers selling their output? Consumers, who have benefited from lower prices and thus seen their purchasing power rise, but have also seen jobs sent offshore? While an emissions cap & trade system with accompanying GHG-leveling tariff could resolve this conundrum going forward, by pricing this externality and letting the marketplace apportion it along the value chain, I can't begin to fathom how to allocate the emissions responsibility for the last decade of this phenomenon.
So if it's not fair to include historical emissions but it's equally unfair to ignore them, and with emissions from the developing world rapidly overtaking the developed world's--but including some ultimately attributable to the latter--where can we find middle ground from which to move ahead, together? Not in the past: the only emissions over which we have control are those that haven't occurred, yet. If the negotiations kicked off with the Bali Roadmap are diverted by arguments over history and fail to focus squarely on the output of the world's twenty or so largest emitters between now and 2050, then they will be fruitless, and we will need to shift our attention to more practical matters of adaptation and possible geo-engineering. We should know the outcome of this debate within a year or so.