Global warming is a complex international problem involving many actors. It is a direct consequence of anthropic emissions of greenhouse gases. Despite the fact that the first universal agreement on climate was signed in Paris in 2015, the international climate régime remains ill-equipped to respond to the urgency of the problem and to address its structural causes.

In 1979, the World Meteorological Organization (WMO) and the United Nations Environment Programme (UN Environment), along with three other UN bodies, organized the First World Climate Conference. These two organizations joined forces to create the Intergovernmental Panel on Climate Change (IPCC) in 1988, consolidating the central role of interactions between science and politics at the heart of the international climate regime.

Climate change indicators

Sources: NASA,; NOAA,; CDIAC,

Comment: Since 1958, has shown the concentration of CO2 in the atmosphere is higher each decade than it was the decade before. The increase is accelerating, so that in 2018, it exceeded the 1958 figure by 30%. Over a longer period, of several hundred thousand years, the current increase in the concentration of CO2 in the atmosphere, linked to human activity, is very sudden and unlike any preceding cyclic variations: concentration never exceeded 300 ppmv (parts per million volume) even at the height of the previous four interglacial episodes. As for the global monthly average temperature, the trend is similar: since 1880, the most recent years have always been hotter, while earlier years have been colder.

Causes and consequences of climate warming

According to the IPCC, the last three decades have been the warmest since 1850. Between 1880 and 2012, the average temperature of the earth’s surface (around 14°C) has increased by 0.85°C. This warming, unprecedented in both speed and scale, is the direct consequence of increased anthropic emissions of greenhouse gases (mainly carbon dioxide, CO , but also methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons and sulfur hexafluoride). While CO emissions are mainly produced by the consumption of fossil fuels (transport, electricity, heating, etc.), by some industries like cement production and by deforestation, anthropic methane emissions primarily arise from agriculture and livestock. Identifying the polluters, though, depends on how we decide to account for emissions (per capita? By country? Emissions from imported products?) and on the timescale selected (since the industrial revolution? Or current emissions?).

CO₂ emissions, 2016

Source: Global Carbon Project, Carbon Budget 2017,

Comment: The Global Carbon Project is a worldwide program, financed by NGOs, which develops scientific knowledge about greenhouse gases. This network’s estimates of CO2 emissions are a benchmark. If emissions are considered by country, China produces the most – almost a third of global emissions – ahead of the United States. Apart from these two main emission-producers, the global geography proves rather similar to the economic weight of different countries (according to GDP). When they are calculated per capita, these CO2 emissions reveal a geographical picture closer to that of the Human Development Index (HDI), with the exception of Europe, where the figures are less than in the Gulf States, North America, Russia, and Australia. They are lower in the countries of the South (Africa, Southern Asia).

Climate warming affects different regions of the globe to differing degrees – the Arctic being the most severely impacted – and the consequences of climate change are unequally distributed, too. Rising sea levels endanger the least developed small island states in particular, and the increased incidence of extreme climate events primarily impacts regions vulnerable to hurricanes, cyclones and tropical storms. Climate variability affects water stress and agricultural productivity, which in turn endangers food security and the living conditions of those populations most dependent on agriculture. Climate change take effect in contexts of vulnerability, where it heightens risks: in the absence of appropriate political responses, this can cause forced displacement and economic, social and political tensions. The causes and consequences of these changes are interdependent and mutually reinforcing. Exposure to climate risks is unequal, then, varying according to the region concerned, the vulnerability of the people affected, the policy responses adopted and other cross-cutting factors.

Sea-level rise and coastal hazards, 2018

Sources: Arenstam Gibbons et Nicholls (2006); Centre for Climate Adaptation (s. d.), Hinkel et al. (2014); IFEN (2006), IPCC (2014), Nicholls et al. (2008), Rowling (2014); Siméoni and Ballu (2012), Win (2014), Wöffler et al. (2012).

Comment: This map, taken from the Atlas des migrations environnementales [Atlas of Environmental Migration], shows the vulnerability of coastal populations to the rise in ocean levels. Two aspects are depicted: the population density of coasts affected by a centennial flood level, and the principal urban areas exposed to extreme flooding. These two indicators, which overlap somewhat, show that the coastal populations of Asia (Bangladesh, Pakistan, India, Vietnam, Indonesia, China, and Japan) are by far the most affected. Other regions are affected more locally, but they still impact millions of people: The Netherlands, the Nile Delta, the Brazilian coastlines, and the southern United States.

Number of natural disasters, 1980-2017

Source: NatCat Service, Munich RE,

Comment: Munich RE is a reinsurance company (that is, it insures insurers) which has developed an activity assessing natural disasters. According to them, the total number of events registered has multiplied threefold since 1980. Storms, and more commonly floods, are the types of disasters that have most increased since that time.

Framing the climate problem

Some studies have described climate change as a wicked problem: one that is hard to diagnose, and that lacks a clear solution. There is no central authority that can impose measures to reduce GHG emissions – yet the radical changes necessary to decarbonize the global economy involve cost-intensive decisions affecting the ways we organize our societies (energy, housing and construction, transport, food, etc.). And these decisions are inevitably shaped by how the problem is perceived – whether it is framed in environmental, economic, legal, ethical, international or individual or other terms. Proposed solutions might complement each other – but might also be based on incompatible choices (green growth versus degrowth, for example). The fragmented international governance system in which they operate might even make them counterproductive, by sectorizing the climate problem, by divesting politicians of responsibility, and by perpetuating the system that caused climate change in the first place.

The UN Framework Convention on Climate Change (UNFCCC), adopted in Rio in 1992, institutionalized the process of international climate negotiations. Following the failure of the Copenhagen summit in 2009, which sought to replace the Kyoto Protocol signed in 1997, COP21 led to the signature of the first global climate agreement (the Paris Agreement) in December 2015. This agreement is based on voluntary pledges made by states, establishing the principle of shared but differentiated responsibility. It also emphasizes the historic responsibility of industrialized nations, although this bias is increasingly contested given the rapid growth of emerging economies, China being currently the world’s largest polluter (in absolute emissions terms), having surpassed the United States. The agreement juggles attenuation policies, which aim to reduce GHGs and limit the global temperature increase to 2°C, and adaptation policies, which focus on strengthening states’ ability to adapt to the effects of climate change.

Climate negotiations involve a growing number of actors (scientists, NGOs, think tanks, economic actors, local authorities, etc.) and are shaped by the interplay of alliances between economic and political interests and coalitions which enable the most vulnerable countries to make their voices heard. Yet the UN climate regime remains out of step with the reality of phenomena such as market globalization, fossil fuel use, economic competition, national sovereignty issues, and so on. This “schism with reality,” identified by Stefan Aykut and Amy Dahan, is characteristic of a system centered on global collective action that disregards local and non-state initiatives, focuses on measuring emissions rather than the structural causes of climate change, and remains isolated from the spheres governing energy, trade and development in particular. The reality schism is heightened by the inherent contradictions involved in setting ambitious but unattainable targets (like the 2-degree threshold).

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