The scientific evidence is now overwhelming that the climate is warming and that human activity is largely responsible for this change through emissions of greenhouse gases.

Governments will meet in Paris in November and December this year to negotiate a legally binding and universal agreement on tackling climate change. Any international policy response to climate change must be rooted in the latest scientific evidence. This indicates that if we are to have a reasonable chance of limiting global warming in this century to two degrees Celsius relative to the pre-industrial period, we must transition to a zero-carbon world by early in the second half of the century.

To achieve this transition, governments should demonstrate leadership by recognizing the risks climate change poses, embracing appropriate policy and technological responses, and seizing the opportunities of low-carbon and climate-resilient growth.

Climate change poses risks to people and ecosystems by exacerbating existing economic, environmental, geopolitical, health and societal threats, and generating new ones. These risks increase disproportionately as the temperature increases. Many systems are already at risk from climate change. A rise of two degrees above pre-industrial levels would lead to further increased risk from extreme weather and would place more ecosystems and cultures in significant danger. At or above four degrees, the risks include substantial species extinction, food insecurity, and fundamental changes to human activities that are taken for granted.

Responding to the challenge will require deploying the full breadth of human talent and invention. Creative policy interventions and novel technological solutions need to be fostered and applied. This will require a sustained commitment to research, entrepreneurship, education, public engagement, training and skills.

Actions need to be taken now, by governments, individuals, businesses, local communities and public institutions, if we are to tackle this global challenge, deliver the required cuts in emissions, and take maximum advantage of the available opportunities and additional benefits.

The report is supplied by the British Consulate-General Shanghai, and edited for publishing by Shanghai Daily.