Paris climate deal: reaction from the experts

While the summit delegates herald their ambitious targets, scientists and campaigners have mixed views of the agreement

The agreement is extremely welcome. However, we should also be cautious. It is clear that the 1C temperature rise over pre-industrial levels that we have seen so far has triggered a whole range of effects including melting of mountain glaciers, significant sea-level rise, devastating droughts, and flooding. These effects are likely to get much worse with even modest future increases. Keeping temperatures to manageable levels also assumes that we know what the precise link is between atmospheric greenhouse gas concentrations and the global temperature response. We don't know this, nor the nature and strength of natural feedbacks in the climate system that might drive future warming.
Stephen Harrison, University of Exeter

For all that is encouraging in the draft agreement, the timescales and lack thereof are worrying. Little substantive will happen until 2020, while clear deadlines for specific targets are generally absent. Even if this agreement is accepted in Paris, plenty of opportunities remain for governments to change and for legislatures to fail to ratify. It will be particularly difficult to deal with the US Congress.
Ilan Kelman, UCL