What can we do about the coincidence of runaway obesity and climate change?

Le résumé fourni par la source

Wherever scientists meet, it is becoming more common to ask whether humanity is getting a grip of the major contemporary challenges raised by scientific research. The lead article by Behrens and colleagues on the obesity and climate "co-crises" illustrates why (1). It raises fundamentally important issues about the way we live today and the drivers of existence.Firstly, the role of science is sometimes described as simply offering data. What to do about problems is left to the realm of policy and politics, not science. Behrens et al. cut through this "facts versus actions" distinction. The topics of obesity and climate are vast in themselves, but when both are seen to connect, it is surely correct to ask whether science's contribution of data, analysis, and advice regarding both has dented the trajectory of events for the better. If not, why not? Is science consigned to plotting the trajectory of falling over metaphorical cliffs? Surely not. The World Health Organization reported that the incidence of overweight exceeded that of underweight by 1995 (2). The United Nations Framework Convention on Climate Change was signed by 154 states (plus the European Commission) in Rio de Janeiro in 1992 (3). The lack of sufficient action on these matters since those dates is not for lack of data or scientific advice given to policymakers. There has been an avalanche.Secondly, Behrens et al.'s article illustrates one of the great successes of science in recent decades-the capacity of researchers and methods to pool data at multiple scales, from micro to macro, from within and across disciplines. The comprehension of complexity now possible is remarkable. This has partly been enabled by advances in technology-computer power, datasets, data pooling, and the capacity of microchips-but also the scientific imagination: asking what might be found if…. The effect is clear. The range of knowledge and the capacity to stand "above" the minutiae of particular studies are now almost taken for granted.We know today how to amalgamate bodies of knowledge and to differentiate between different methods for doing so. But the desire to do this is not modern. Many advances in science have been when boundaries are pushed, when different bodies of knowledge are juxtaposed. Recognition of this process informed, for instance, Thomas Kuhn's great thesis that science develops when paradigms-frameworks of understanding-are found wanting and replaced by newer frameworks that explain, or make sense of, the previously denied or ignored (4). Thirdly, asking "why?" inevitably leads to "what can be done?" The schism is not pure versus applied science. Historians of science sometimes suggest that these questions are reversed, and that a concern for change leads to questioning of the status quo. Twentieth century historians, for instance, argued that the explosion of innovation and commercial exploitation characterizing the development of industrialization was directly associated with the loosening of religious strictures on knowledge (7). As previously powerful European religions fragmented, it became possible to question norms and to think "outside the box".The spread of broad, ecological, and interdisciplinary thinking that began in the "gentleman science" era of the mid 18 th and 19 th centuries spread across society. Questioning existing frameworks of knowledge and daring to ask "why" characterize the growth of science. In the past, only those with private funds, facilities, and sufficient mental "space" in their lives could both ask why and pursue how to answer the question. Technical change more than pure science shaped the emergence of disciplines. This was gradually replaced by professionalized and more strict disciplinary focuses. Now, as Behrens et al. show, science can again capture the scientific imagination by offering data on a scale that was unthinkable a few decades ago. Surely, progress must follow from this power? But perhaps what is missing is a "narrative" of how to unlock the lock-ins.Fourthly, there is a worrying possibility that boredom might be setting in. If glucagon-like peptide (GLP)-1 receptor agonist drugs can seemingly cure obesity, why worry about it?Why not look to such technical fixes? We meet a friend, previously obese, but now find a slimmer echo. Those who can afford the bill, can cure obesity. This is the tantalizing prospect offered by some. In effect, it sidesteps rather than rebuts the systemic analysis of obesitythat social conditions determine population outcomes. Instead, the chimera of personalized medicine offers a resolution. But does it? These drugs come at immense cost and the parent pharmaceutical companies are subject to the vagaries of stockholder values. The equivalent technical fix approach to climate change is carbon capture (8). But few climatologists expect this to achieve the scale necessary to tame, let alone reverse, global warming.Fifthly, there is the matter of the public, not science. Behrens et al. expose the gap between science and policymakers, but will pressure from the public succeed where science is failing?We discern the obesity pandemic when walking down the street or when comparing photos across generations, for example within families or on beaches or in crowds. At the same time, we experience climate change in our gardens and towns, in the weather wherever we are. We should not need to read vast reports on obesogenic trends or witness glaciers melting.Immense scientific data and bodies of knowledge on obesity and climate change dovetail with human observation. What matters, however, is not the trends but our acceptance of their normalization. We barely remark on it. We take more notice when the previously overweight shrink. But both trends can coexist. The world gets fatter overall while some individuals get thinner thanks to the efficacy of a medical revolution. Meanwhile politicians shrug their shoulders and huge externalized costs are dumped on future generations (9). This gap between people's lived experience of these new normals and the need to tackle the implications of scientific data remain firmly in the "too difficult to handle" policy box.The policy-evidence-action gap can no longer be ignored or categorized as a problem only for specialists or policymakers. It is everyone's problem. The scale of the obesity, food, climate challenge requires a major recalibration of food supply and availability. Humanity is currently living with the outcomes of the post-World War II, mid-20 th century experiment with food. Seventy years of apparent success has in fact breached planetary boundaries. Life itself is threatened. The Malthusian problem of population growth exceeding the capacity of food supply may have been answered in the last century by a combination of economic wealth and technical advancement, notably the Haber-Bosch system for fixing nitrogen from the air. However, that model of pumping nutrients into the soil to accelerate plant growth is now running out of room. It has created vast environmental problems. The challenges now facing humanity and its diverse food systems are how to balance modes of consumption, production, and distribution with ecosystems, livable economies, and population health.If policymakers fail to act rationally in response to such data, at what scale might shocks and a rising scale of damage drag them to into action? Or will a combination of public alarm and societal disruption provide the missing incentive?

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.