In the run-up to the grand climate meeting in Paris this December, countries are publishing their commitments. Mexico earned much praise for proposing to cut its greenhouse gas (GHG) emissions by 22% by 2030. But this exemplary reduction is relative to what Mexico might otherwise have emitted in 2030 – and constitutes a substantial increase over its 2013 emissions. Even on a per-capita basis, Mexico is proposing merely to keep its GHG emissions flat at 5.9 tons of CO2 equivalent.
Mexico’s celebrated proposal foreshadows that governmental commitments will be nowhere near sufficient to keep the rise of the global average surface temperature below 2 degrees Celsius. It is the scientists’ consensus that respecting this limit is necessary to avert a climate catastrophe and requires keeping humanity’s cumulative post-2011 CO2 emissions below 1 trillion tons for a 2/3 probability of staying below the 2°C threshold (IPCC Synthesis Report, Table 2.2, page 64). If humanity emits GHG at Mexico’s rate of 5.9 tons per person until 2030, we will have used up 87% of our remaining CO2 budget by then.
A severely worsening climate would inflict immense harms upon poor and vulnerable populations: through extreme weather events, flooding of coastal areas, scarcity of food and water, spreading disease vectors and violent struggles over diminishing natural resources. Predictably, these harms will jeopardize human rights by causing millions of premature deaths and unimaginable deprivations. Given this prospect, is it permissible to continue emitting CO2 at Mexico’s rate – or at the even higher rates of the EU or US (currently 7 and 16 tons per capita, respectively)?
Morally, the answer is clear; it would be wrong to risk such catastrophic harms. But many assume that states are legally free to continue in their polluting ways unless and until they have contracted otherwise. Exactly this assumption has now been challenged by an international group of eminent jurists in their Oslo Principles, supported by an elaborate legal commentary. ASAP President Thomas Pogge helped convene the group of legal experts who wrote the principles.
The essence of the Oslo Principles can be conveyed in three steps. First, according to the best joint interpretation of international law, human rights law, national environmental law and tort law, it would be unlawful knowingly to inflict the harms that a large majority of climate scientists predict may well result from exceeding the 2°C threshold.
Second, honouring the precautionary principle, we must not proceed with any course of action if a substantial proportion of climate scientists judge it to court a serious risk of a catastrophic outcome. It is not legally permissible to subject the human rights of billions of present and future persons to a game of Russian roulette.
Third, states are legally required collectively to restrain emissions so as to stay below the 2°C threshold. They can meet this requirement through a sufficiently strong and effective agreement. Failing that, each is legally required – regardless of what the others do – to do its fair share toward meeting the collective legal obligation. Doing one’s fair share involves reaching a glide path that takes per capita CO2 emissions down from the global average of about 5 tons today to about 1 ton in 2050 through steady reductions of about 4.5% each year. There is no good reason why any national population should be entitled to a more favorable glide path than others.
According to the Oslo Principles, countries above the required glide path are legally required to take all reasonable measures to reach it as quickly as possible and, insofar as they cannot reach it immediately, must take compensating action by funding emissions reductions in poorer countries so as to offset their own excess. Countries below the glide path must take all emissions-lowering measures whose net costs are either nil or covered by others. The poorer countries need energy for their development, of course. But this should be green energy that adds at most minimally to atmospheric greenhouse gases.
A climate catastrophe is threatening our planet. Each country can do its fair share toward reducing humanity’s carbon emissions and has a legal obligation to do so. By explicating and enforcing this legal obligation, legal scholars and national and international courts can play a crucial role in averting one of the largest systematic human rights violations in human history.