When learning biology for my school exams (longer ago than I imagine but not so many years ago) I clearly remember that atmospheric carbon dioxide (CO2) was rounded down to 0.03%. If I gave that answer today it would be marked as incorrect. According to the US government’s Mauna Loa laboratory, atmospheric CO2 has now risen above 400ppm for the first time in human existence.

I came across this information on a news website last week. It was a relatively small headline under “Science and Nature.” The real headline that day being the retirement of the Manchester United boss. The CO2 news has been repeated by a number of news sources with its prominence dependent upon each news outlet’s political and economic stance.

I have been to work for three weeks since I read the CO2 news. I have not had a single conversation about it nor heard it mentioned by anyone. I have though had at least three conversations about the possible new manager of Manchester United (thankfully a question now resolved).

What has amazed me for some years is the apparent indifference of large numbers of human beings to the possible cataclysmic changes in the climate that we may be causing. Climate change deniers are vocal, but far more common are those who don’t really worry because any effects will be some vague time in the future. Like all of us they are busy getting through their day—whether a subsistence farmer in Africa or a financial services worker in New York wondering if the next round of redundancies will involve them.

Whilst I can sympathise with the distractions of daily existence, what I have never understood is the needless use of fossil fuels. A couple of years ago I was watching David Attenborough’s Frozen Planet in which he was warning about the real danger of melting of the ice caps and the vicious cycle that could ensue. Following this, on BBC TV, was coverage of the Indian Grand Prix! Is there anything more gratuitous in its glorification of pollution than motor racing? What contradictory message does this give to the average viewer? Or is it perhaps a very subtle example of BBC balance?

I often wonder if doctors have a moral responsibility in regard to climate change. We have a direct responsibility for our patient’s internal environment so perhaps we have a duty to their (and our) external environment? It seems likely that global warming will bring with it adverse health effects and perhaps, like smoking, we should strive to warn patients of direct dangers to their health if CO2 levels continues to rise?

If we do have a responsibility then we need to be (and be seen to be) environmentally friendly. We should ensure our work places recycle, use renewable sources, and don’t waste energy. We could be seen to be walking or cycling to our place of work. We could forgo our shiny BMWs or Mercedes for low emission vehicles or even (horror of horrors) use public transport when possible.

Then again perhaps we do not have a moral responsibility as far as the external environment is concerned. We are not moral arbiters of our patient’s behaviour—quite the contrary in fact. We are however generally intelligent, well read human beings who can make our own minds up about the anthropomorphic element of global warming. Many doctors may not be convinced about climate change science though I have to say that I am. Even if I weren’t I would have thought it prudent not to take the risk of assuming we are in a natural cycle of increased global temperatures rather than one we have created ourselves.

Looking back to those school exams, part of the science syllabus concerned climate change and global warming. Indeed this was the first time that I became aware of the possibility. Since then the warming trends have continued and the evidence for man made climate change has become stronger. Yet we continue to pollute our planet at a greater rate. I can only assume when my grandchildren are doing their science exams that the correct answer will be 500 ppm of atmospheric CO2. Will this be the figure where something is done or will the next Manchester United manager take the headlines?

Scott Fraser is a Consultant ophthalmologist at Sunderland Eye Infirmary. He is visiting professor at the University of Sunderland and adjunct professor at the University of New England.

I have read and understood the BMJ Group policy on declaration of interests and declare the following interests: None.