An ineluctable reality of global carbon diplomacy is that the biggest emitters must step up to the plate first, and none, including small nations, can expect to be free riders, as overall change hinges on cumulative emissions. This has been staring the world in the face for over 20 years - from the 1992 Rio Conventions to the ineffective 1997 Kyoto Protocol to the failed 2009 Copenhagen summit. Such has been the foot-dragging over the years that the recent effort by China to make common cause with the United States to curb emissions was widely described as a historic landmark agreement.
The move is significant, being a first-ever commitment by the world's largest greenhouse gas emitter, but critics despair over the paucity of China's effort and the sloth-like progress in general. China is pacing itself for peak emissions by 2030 before progressive decarbonisation of the economy results in a decline. President Barack Obama has put on the table a doubling of the pace of reductions targeted by the US from 2005 to 2020, and the European Union has made climate action a strategic priority. Regrettably, India, another major emitter, has yet to accede to emission caps, and many other countries have similarly chosen a blinkered approach to the dangers.
In the circumstances, it is right for the Paris climate conference, scheduled for the end of next year, to be seen as an alliance more than a top-down treaty. It is only via an aggregation of rigorous targets and action plans by governments that the world can hope to keep within the remaining quota of warming gases. It's vital to avoid an increase of 2 deg C - the accepted threshold before rising average surface temperatures lead to devastating consequences.
The China-US agreement gives cause for some optimism that the Paris summit will lead to substantive progress in key areas. This is more likely to happen if the home truths about climate change take hold widely. Domestic imperatives might loom large when growth is a big concern, but none are spared when climate change results in extreme weather and affects millions around the world. Declining biodiversity and natural resources are also putting greater pressure on businesses.
A strong Paris accord will help bring about a low-carbon global economy and give governments the confidence to pursue sustainable strategies without looking over their shoulders at competitors. Crucially, the framework must be backed by "a clear, shared accounting system and robust, transparent monitoring and reporting requirements", as advocated by a group of blue-ribbon environmental organisations. A low-carbon future is realisable only if all play active roles.