MEDICAL METAPHORS FOR CLIMATE ISSUES An Editorial Essay RICHARD C J SOMERVILLE Scripps Institution of Oceanography University of California San Diego La Jolla CA 92093 0224 USA E mail rsomerville ucsd edu We climate scientists are planetary physicians We have learned many things about climate but we still have a lot to learn Like the findings of medical science our understanding of climate although incomplete is already highly useful For example the fundamental question of whether all of us more than 6 billion humans by adding to the greenhouse effect have caused the world to warm up in recent decades has already been answered The answer is yes We ve settled that issue At least we climate scientists consider it settled Some people may choose not to believe it There are people who are unwilling to believe things that they wish were not true or who simply don t trust experts The public has come to respect medical science however and although there will always be gullible people most of us know there s a difference between real experts and charlatans Most people won t listen to or act on medical advice from a quack who can talk plausibly about medicine but who isn t really a physician Everybody accepts this situation Even the least enlightened members of the U S Congress don t hold hearings to denounce modern medical science as a hoax Yet a few politicians and hard core skeptics do attack climate science in exactly this way Medicine is different At your annual checkup if you re sensible when the doctor tells you to lose weight and exercise more you don t argue You don t insult your doctor by complaining that medical science is imperfect and can t yet prevent cancer or cure AIDS You don t label your doctor a radical alarmist You know and your doctor knows that medical science while inevitably incomplete is still good enough to provide advice well worth following Of course some people just will not do what experts tell them Non compliance by some patients is a big problem for physicians We should keep all this in perspective Lest we fall into the trap of thinking that medical science is a perfect role model for us climate scientists who crave public esteem it is also good to remember that it took a long time for many medical results to acquire widespread acceptance Some This essay is based on a talk given October 8 2005 at the Yale Conference on Climate Change From Science to Action held in Aspen Colorado USA Climatic Change 2006 DOI 10 1007 s10584 006 9084 8 c Springer 2006 RICHARD C J SOMERVILLE scientists in the 1930 s already suspected that tobacco caused cancer The evidence was widely known to be strong by the 1960 s Yet the high profile anti tobacco lawsuits began in the United States only in the 1990 s Globally there has been a reduction in tobacco use in numerous countries Throughout the world however many people still smoke The big problem in human caused climate change is carbon dioxide emitted into the atmosphere by human activity We produce most of it when we burn oil and coal and natural gas to generate energy It adds to the greenhouse effect and causes climate change A few far seeing scientists realized this clearly more than a century ago Yet accurate measurements of carbon dioxide in the atmosphere began only in the late 1950 s We have known for only about half a century that atmospheric carbon dioxide is increasing We ought to remember this half century time scale when we get impatient about the slow pace of progress in action against human caused climate change Incidentally like many climate scientists I have an aversion to the catchy term global warming although I realize it s in the language to stay It s an oversimplification Climate is far more than just temperature Climate is a rich tapestry of interlinked phenomena multi faceted and inherently complex The most important aspects of climate change are local not global and are not confined to warming Global warming is just a symptom of planetary ill health like a fever You and your physician both know that fever is important but is not the whole story At your annual checkup you don t confine yourself to body temperature when discussing your health Even the most ignorant patient realizes that measuring temperature alone cannot enable the physician to diagnose an illness and prescribe treatment Instead everybody knows that a body temperature only a few degrees above normal is a symptom that can indicate medical problems that may have serious consequences sometimes including death Yet we still haven t educated most people to understand that a planetary fever of a few degrees can mean melting ice caps rising sea level massive disruptions in water supply killer heat waves and stronger hurricanes Many intelligent people still laugh at the small numbers we use in describing climate change They think a global warming of a few degrees is trivial They may say that moving from one city to another often involves a much greater warming yet may actually be quite pleasant These people don t grasp the important difference between local changes and global ones They don t realize that when the surface atmospheric temperature of the entire planet changes by a few degrees the implications are enormous Entering an ice age to cite one example involves a global cooling of only a few degrees Many people also mistakenly believe that a rapidly warming climate is just a minor inconvenience that can be handled by air conditioning and other simple technological fixes This massive degree of misunderstanding may be due in part to a failure to educate people about science It may also be the case that people MEDICAL METAPHORS FOR CLIMATE ISSUES have become confused by the widespread misperception that the science of climate change is immature uncertain characterized by raging controversy and not to be trusted An effective campaign of deliberate disinformation about climate science has helped spread this false impression Medical science has achieved a measure of widespread respect that climate science can only envy Journalists covering a medical discovery aren t usually suspicious of researchers and don t inevitably insist on hearing from the opposing view When reporting on research showing the need for people to eat sensibly and be physically active the media do not frame the story of these scientific advances in terms of a debate or dispute Journalists don t feel obliged to seek out medical contrarians for balance There are many parallels