Interdisciplinary Science Reviews

This paper reviews the climatic history of northern France from the grape harvest dates of the Burgundian vineyards. The grape harvest date is constrained by the mean surface air temperature during the growing season (April–August). At the start of the grape harvest dates series – during the 1380s and from 1415 to 1435 – the tendency is towards early harvest dates and warmer conditions, starvation due to crop scorching in 1420 included. During the second half of the ‘Quattrocento’, there are later harvest dates and cooler springs/summers, exemplified by the 1481 famine, due to rain and cold. The 1500s, 20s, 30s and 50s are characterised by blasts of warmer summers. The ‘midsummer night's dream’ (1596/7) can turn into a nightmare … Then, a cold ‘long seventeenth century'? This is quite pronounced from 1570 to 1630, with, however, a slight improvement around 1600–20. Major waves of hot summers were experienced during the 1630s, 60s and 80s. Is the Maunder minimum, between 1645 and 1715, responsible for a slight, synchronous, cooling? In this case, it would be mainly the Late Maunder Minimum (1675–1715), with the chill of 1675, the 1690s and 1709–1715. Then the great warming of the eighteenth century: the years 1704–07, 1718/9, the 1720s and 30s, 1757–65, the 1780s and above all 1778–81 all favour this interpretation, though we must not forget the cold, wet years 1725, 1740 and 1770. The years 1812–17 are not only snowy but also globally cold (due to the Tambora eruption in 1815 and the Dalton minimum?). And then there is the 1846 heatwave, so harmful to cereals. The Little Ice Age ends in 1860, with no return up to the present, the twentieth century warming from 1900, with an intensification of the phenomenon from 1976 and particularly the 1990s.

In the current context of climatic changes, climate science is becoming increasingly a focus of attention for large portions of society. At the same time, our basic understanding of climate processes is evolving very rapidly, following tremendous advances in Earth observation as well as in computing power. Still, the very notion of ‘climate’ appears not all that well defined, the physical contours of a ‘climatic system’ are often rather dependent on the given scientific question, and there is little obviously in common between – for example – researchers studying the climatic conditions experienced by the dinosaurs, those attempting to use satellite information to better quantify the present-day climate, and those who use the largest computers available to predict possible dire consequences of current global warming. But appearances are sometimes misleading. Indeed, climatology is in its essence highly interdisciplinary, and it has numerous firm connections with many other scientific disciplines in the physical, natural and human sciences. But first of all, it is necessary to discuss what is hidden behind the word ‘climate’. In particular, in order to move from a phenomenological towards a more physically-based view, a key question is to draw the contours of a climate system. In this respect, it is interesting to note that climate modellers are now increasingly defining their object in terms of an ‘Earth system’ instead of a ‘climate system’. I go on to present some recent progress in climate sciences over the last few decades. In particular, based on recent paleoclimatological discoveries, the climate appears now as a very dynamic system, with its own internal variations. The finding that past climate has changed ‘spontaneously’ and very abruptly, on a decadal timescale, has profoundly changed our vision of climate dynamics. Finally, I outline some possible future directions for climate sciences: ‘Earth system science’ is an emerging discipline that has the ambition to describe, in the same mathematical framework, the past and the future evolution of our planet.

This paper examines the genealogy of long-term studies in economics and its mobilisation in climate change research. Long-term studies differ from short-term forecasting and planning not only in their length of foresight but also by taking account of strategic and policy objectives. These strategic considerations are not within the scope of longue durée historians, nor are they integrated into econometrics or national accounting practices of forecasting. Only planning and prospective analysis include this dimension. The method of scenarios is then at the core of long-term studies and prospective approaches. The conception and use of scenarios is reviewed through various national and international studies since the 1970s – DATAR, OCDE, CPB and, finally, the IPCC scenarios report – as well as their implementation in integrated assessment models (IMAGE, for example).

When modelling is conceived as a means to illuminate policy-making in the field of climate change, modellers tend increasingly towards integrated assessment models to catch interactions between natural and economic systems on both sides. Ultimately models should elicit ‘projected equilibrium’, when achievements match expectations. Should we support this tendency, or should we set moral limits for the sake of freedom of choice of all generations? How should we view adaptation to climate change in the context of intergenerational ethics? Taking the Stern review as a background, this paper suggests that the use of fully integrated models for policy-making meets ethical difficulties and is caught up in paradoxes. The more we consider a long-term future, the more modelling should be disentangled and split into separate scenarios. It is also suggested that the focus of modelling should not be on maximisation of per capita consumption, but on how ecological capacities and human capabilities can be maintained or developed over time.

This paper considers the Intergovernmental Panel on Climate Change (IPCC), and in particular its key role in climate change dynamics. It highlights the significance of the links between scientific expertise and global governance, politics being a crucial issue between North and South. It thus studies the operation and activities of the IPCC, which on the one hand defends the traditional model of scientific expertise, but on the other is closely linked to political dynamics.

A global climate observation system is essential to improve our understanding of the climate system and our ability to anticipate trends. This article addresses the criteria that such a system must meet, and the range of observation techniques which must be implemented. Observations collected by satellite must be calibrated, validated and supplemented by surface and subsurface measurements in the atmosphere, the ocean and on land. All these observations need to be used in conjunction with numerical models and data distribution networks, and maintained in a complex of centres for archiving and reprocessing of environmental data. A global effort is required to meet these challenges, based on intensive international cooperation. The article describes activities in Europe and elsewhere, among them the World Weather Watch of WMO, the European initiative GMES (Global Monitoring for Environment and Security), and particularly the GEOSS (Global Earth Observation System of Systems), developed in the intergovernmental framework of GEO (Group on Earth Observations) to overcome obstacles of all kinds and achieve the objectives of a global climate observing system.

Citizen science, defined as participation of the general public in scientific research, could significantly help scientists to address biodiversity issues, through (i) monitoring the state of biodiversity, (ii) framing indicators which synthesise and communicate information on the state of biodiversity, (iii) building scenarios to evaluate the plausible consequences of different policies. A key asset of citizen science is that participating citizens disseminate the information they gain, thereby increasing the profile of issues being researched. We review further benefits associated with biodiversity monitoring, indicators and policy scenarios, envisioned as collaborative tools between scientists and citizens. Such collaboration promotes both the scientific adequacy and social legitimacy of these tools, so that they can meaningfully inform debates and decisions on public policy.