Johan Rockström of the Stockholm Resilience Centre presented a roadmap for rapid decarbonization at COP23. The roadmap proposes halving global carbon emissions every decade to be consistent with limiting warming to below 2°C, as called for in the Paris Agreement. Rockström et al. published a 2017 Science paper outlining emissions profiles that halve circa 550 billion tons of CO2 by 2060 to stay within carbon budgets. If renewable energy adoption continues doubling every 5-6 years as the current trajectory, renewables could power all primary energy needs before 2050. The "Carbon Law" of halving emissions each decade provides a decadal pathway to translate the Paris Agreement into urgent