Policy: Climate advisers must maintain integrity

Disenchantment has set in well ahead of the 21st Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change (UNFCCC) in Paris in December. Scientists, policy-makers and the public already accept that progress will not be enough to keep global average temperature rise within the 2 °C limit set at the 2010 UN climate summit. The negotiations’ goal has become what is politically possible, not what is environmentally desirable. Gone is a focus on establishing a global, ‘top down’ target for stabilizing emissions or a carbon budget that is legally binding. The Paris meeting will focus on voluntary, ‘bottom up’ commitments by individual states to reduce emissions. The global climate target is being watered down in the hope of getting any agreement in Paris. The 2 °C warming limit need only be kept ‘within reach’. The possibility of using ‘ratcheting mechanisms’ keeps hopes alive of more-ambitious policies, but such systems are unlikely to achieve the desired outcomes. Strict measuring, reporting and verification mechanisms are yet to be agreed. There is another casualty: scientific Climate advisers must maintain integrity