National commitments to reducing global CO2 emissions are in the spotlight again after the recent United Nations talks.

Earlier this year, the Intergovernmental Panel on Climate Change (IPCC) published their strongest statements yet about the possible health impacts of global warming. These impacts include increased vulnerability to disease and injury through a variety of mechanisms, including: climate and weather variability; changing patterns of vector borne diseases; and changes to air quality.

In response to the IPCC’s report, our editor in chief, Fiona Godlee, sets out a case in The BMJ this week for the World Health Organization declaring a public health emergency on climate change. Meanwhile, Bob Roehr tells us that China is digging its heels in and asking to be still considered a developing nation. This might be disputed by Hans Rosling. His impressive Gapminder data visualisation shows how countries have developed in terms of health and wealth over the years—it seems that the divisions between the development level of nations are becoming smaller and smaller.

But how can global health continue to improve? Jocalyn Clark feels that medicalisation is not always the solution, and says that tackling the root causes of social barriers to health is likely to be more productive.

Gavin Yamey, meanwhile, favours a multiplicity of approaches, including combining “horizontal” and “vertical” approaches—thus thinking more in terms of “diagonal” approaches to health.

Will Stahl-Timmins is The BMJ‘s interactive data graphics designer.