Introduction

1Awareness of climate warming and its global consequences has not yet made it possible to reduce the effect of human activities on the climate. The failure of international policies to coordinate a reduction of greenhouse gas1 emissions together with the observation of certain effects of warming that are faster than expected means that a shift in the direction of negotiations is necessary today.

2The 21st Conference of the Parties (COP 21) of the United Nations Framework Convention on Climate Change to be held in Paris in December 2015 should be a turning point in the political handling of the climate question. Beyond the ambitious universal and restrictive agreement that is hoped for, COP 21 will be more pragmatically the venue for a bottom-up approach to national contributions and the schedule for solutions, with each country contributing according to its means and according to the priorities in national policy with regard to the effort made to fight climate warming and its impacts. The final objective of the Convention is no longer that of spreading greenhouse gas emission reduction undertakings among states but that of incorporating the question of the climate in broader problems. This being so, the climate question is joining the sustainable development goals (SDGs) negotiated by the United Nations in 2015 and is also open to local initiatives by all stakeholders in society.

3This new framing of the climate question thus requires better understanding of local greenhouse gas emission conditions in order to limit them (mitigation), whatever the human activities concerned. It also involves better description of the diversity of the impacts of global warming on the planet, bearing in mind that all environments and all humans are concerned, and even the regions with small emissions or those that are remote from major sources of emission. This evolution matched the scientific approach aimed an explaining how local emissions contribute to the warming of the atmosphere and how this then has different repercussions in different regions of the world. These specific effects depend on the climatic risks in the region, the degree of exposure and sensitivity of the environment to these risks. Distinction between the direct impacts of the increased concentration of greenhouse gases and other pressures related to regional and local socio-economic activities is another challenge to scientists. Finally, the responses to be provided are conditioned by the variety of local social, health, cultural and economic contexts. Such complexity requires reflection on the definition and implementation of appropriate solutions for adaptation and innovation.

4Faced with such issues, interdisciplinary research must respond to three priorities: issuing the necessary alerts and monitoring climatic and environmental evolution, accompanying evolution by local innovations and recommendations concerning public policies and finally providing a critical analysis of international policies in order to render them compatible with sustainable development goals. The reality of climate warming and its repercussions is now clear but monitoring on-going changes is no less crucial. Setting up coordinated mitigation measures requires continuous monitoring accompanied by continuous information for civil society. This is aimed at sharing knowledge about the evolution and scale of changes with the largest possible number of people and reducing the zones that lack clarity in order to better quantify and anticipate the environmental and societal risks to come. This approach is based in particular on the strengthening of socio-environmental monitoring facilities and the improvement of integrated modelling tools.

5In the field, research must bring the question of climate change out of isolation by giving it social, economic and geopolitical dimensions and enabling better hinging of practices and means of action. This approach is more closely integrated than ever and must make it possible to link the diversity of environmental and societal dynamics and assess the degree of resilience of ecosystems and populations. By better taking local practices into account, the approach should also make it possible to devise solutions that reconcile adaptation to climate change, conservation of the environment and the enhancement of sustainable human development.

6For IRD, the mobilisation centred on COP 21 in France is an opportunity to take a long look at the research related to climate change conducted with its partners in the North and the South. In this book, the institute wishes to promote its most recent research results, highlight the specific features of environments and populations in the South and justify its engagement in a resolutely involved research approach. The linear structure running through the three parts results from a wish to make this complex reality more accessible, but the work is firmly founded on an ‘integrated’ scientific approach to the climate question in the South.

7The first part, entitled ‘Observing and understanding climate change’, is aimed principally at repositioning global climate warming with human causes in the perspective of the natural climate changes observed over long periods in tropical environments. Their exceptional nature is demonstrated. But the scientific approach is also highlighted—the rigour and caution required for pinpointing the causes of a variation or an extreme event observed at the local or possibly regional scale. Indeed, even if the reality of global climate warming has been shown, it is primordial not to wrongly hold it responsible for all the changes observed. Such errors could lead to ineffective or possibly counter-productive adaptation policies. In order to be pertinent, the approach must be based on observation networks adapted to the critical spatial and temporal scales for the continuous monitoring, detection and precise description of possible anomalies in the evolution of the climate and the environment. It must also benefit from high-performance modelling tools to determine the mechanisms involved and to identify the factors causing the anomalies. The reliability of these models also determines the confidence that can be awarded to the climatic scenarios compiled for the coming decades.

8The second part, ‘The impacts of climate change in the South’, addresses socio-environmental repercussions by major type of ecological environment in order to show the complexity of the processes involved and the large number of determinants. Oceans, coastal and island zones, semi-arid zones, highland zones, humid zones and forests and large cities are all environments threatened by climate change. However, the risks are expressed in distinct ways as each environment is subjected to specific climate threats with variable amplitudes (cyclones, floods, droughts, heat waves, rise in sea level, etc.). Furthermore, climate change is just one factor among other changes (deforestation, population growth, pollution, over-exploitation of natural resources, etc.) that can have drastic short-term effects on ecosystems and resources that sometimes outweigh climate change. It is then very difficult to discern the respective influences. Each environment also features vulnerability to a particular climate risk that is often aggravated in southern countries for reasons of poverty, inequality, poor governance and limited means for control. This means that the risks caused by climate warming take very different forms according to the environments concerned. This justifies the regional approach used in the second part of the book.

9The third part, ‘Societies and the test of climate’, puts political and social reality at the centre of preoccupations concerning the climate. The initial framing of the climate question by the United Nations Framework Convention on Climate Change (UNFCCC, 1992) as a planetary pollution problem did not allow, in particular, the mobilisation of societies and the world economy in a search for solutions to reduce the influence of human activities on the climate. Critical analysis of international negotiations on climate makes it possible to question this framing of the climate question. Beyond the climatic dimension, international climate policies are studied as a process of construction of global environmental governance affecting national environmental policies.

10The expected consequences of climate change in questions of health call for a strong international public health policy that would enhance the resilience of societies in the South with regard to the new health risks and improve their wellbeing. Health research must also use long-term studies of populations performed by monitoring facilities devoted to the environment, demography, farming and farming processes and also the socio-economic evolution of societies. Even when changes are extreme and have immediate health repercussions, monitoring facilities must analyse and monitor them over long periods of time. This long-term analysis will lead to adaptation scenarios that fully take into account the health and well-being of populations.

11The capacity of populations to face climate change issues does not depend only on the desire of decision makers to mitigate its effects: populations in the South have not waited for decisions by experts to adapt their strategies and behaviour to environmental changes. Indeed, mobilising populations requires an effort to understand the diversity of sensitivity and ecological practices. The question for scientists and politicians is therefore that of drawing inspiration from cultural experience of climate change in order to better design the actions to be undertaken. The numerous studies mentioned in Part 3 illustrate the adaptation capacity of rural populations in the South that are in close interaction with their environment. This applies in particular to their farming practices and management of resources. Using examples of recent programmes implemented in the South, the last part of the book thus shows the major role of men and women and of social and political aspects in the face of the climate challenge.