• No summer since 2015 has gone without an extreme heat wave, according to our partner The Conversation.

  • Since it is too late to prevent them, it is time to adapt to the - inevitable - crises to come.

  • The analysis of this phenomenon was carried out by Magali Reghezza-Zitt, lecturer in geography at the École Normale Supérieure - PSL.

Global warming will change the intensity and frequency of weather and climate extremes, the IPCC has been warning for several years.

It will act on the recurrence of events of average intensity, the date of appearance of certain hazards - heat waves outside the summer season, for example - or their location.

Rising temperatures, changing precipitation, rising sea levels will affect human health and that of ecosystems.

These disturbances will modify the living conditions of exposed populations and threaten activities that depend on temperatures and precipitation, water resources, biodiversity and soils.

The effects of climate change will affect the populations as well as the productive sectors, financial systems, trade, mobility, etc.

Studies show, however, that the increase in claims by 2050 will result from the combination of natural climate variability, global climate change and the socio-demographic dynamics specific to each region.

The role of companies is therefore decisive.

Their resilience will depend in particular on the responses implemented within the territories.

They are found as much in attenuation, which is essential, as in adaptation, a term of everyday language used first in biology to speak of evolution, then in social sciences to account for the complex interactions between nature and human societies.

Aerial view taken in eastern France, September 15, 2020, showing the dry Doubs © Sebastien Bozon / AFP (via The Conversation)

France's climate is already changing very quickly

Climate change is already here.

During the 20th century, the average temperature in France increased by 0.1 ° C per decade, with a recent acceleration leading to a gap of 1.8 ° C above the pre-industrial era.

Heat waves are more frequent, the duration of snowfall decreases.

No summer since 2015 has gone without an extreme heat wave.

Cyclones of extreme intensity, like Irma, appear.

The evolution of precipitation is more contrasted, with an increase over two-thirds of France and a more pronounced seasonality.

If there is no increase in the frequency of storms, extreme rains are more intense and more frequent in the Southeast.

Map of the impacts of climate change already visible and to come by 2050 for France © Ministry of Ecological Transition, CC BY-NC-ND (via The Conversation)

Scientific advances now make it possible to attribute specific events to climate change, that is, to assess how many times a particular event is more likely due to human activities.

The causal link is demonstrated for heat-related events, extreme rains, and studies are underway for the other phenomena.

It is therefore necessary to improve immediately the warning, crisis management and compensation systems, and to take climate change into account in public policies, because the associated risks have increased.

At the heart of climate policies, mitigation and adaptation

But we must go further.

Climate action is part of the logic of disaster prevention: resilience is based on the ability to control shocks and stresses upstream and to prepare for crises that we know are inevitable.

To do this, it is both possible to act on the causes and the effects of climate risks.

The latter result from the combination of three components: climatic hazard and its derivatives, ie all the disturbances caused by global warming;

direct or indirect exposure of socioecosystems;

vulnerability, ie the level of sensitivity of these systems and their components to various hazards.

A polar bear leaping between two blocks of ice in the melting pack ice, on the island of Spitsbergen, in the Norwegian archipelago of Svalbard © Arturo de Frias Marques / Wikimedia, CC BY-SA 4.0

Climate policies must therefore aim to mitigate the hazard - global warming - by reducing greenhouse gas (GHG) emissions and achieving carbon neutrality, and to adapt by reducing exposure and vulnerability to impacts.

Adaptation, like mitigation, relies on a wide range of actions, which range from ad hoc or gradual adjustment, which does not fundamentally modify the system, to structural transformations which branch off the system by attacking the root causes of vulnerability and exposure.

Synergies between mitigation and adaptation

Mitigation and adaptation are complementary.

If for a long time adaptation was seen as a palliative solution to mitigation failures, these two aspects of climate action are not substitutable, if only because it is already necessary to adapt to climate change. current climate changes.

Postponing mitigation efforts mechanically increases the adaptation efforts to be undertaken, but also limits the possibilities of this adaptation.

The IPCC reminds that there are thresholds beyond which it is no longer possible to adapt, especially for the most vulnerable.

Figure taken from chapter 6 of the IPCC report “The ocean and the cryosphere in the context of climate change” (2019) showing the different types of action possible to deal with disruption © IPCC, CC BY-NC-ND (via The Conversation)

Mitigation and adaptation call for responses that can go hand in hand.

Nature-based solutions thus combine mitigation, adaptation and protection of biodiversity.

But adaptation can also harm mitigation - air conditioners or seawater desalination for example, biodiversity or well-being.

Finally, necessary and effective short-term responses can be a source of poor adaptation or poor attenuation in the medium and long term (dikes, water reservoirs, etc.).

It is then necessary to make choices.

Therefore, mitigation trajectories, and even more adaptation, are not given: they must be publicly and democratically debated, based on available knowledge, revised based on assessments, social and technical innovations, evolution of values.

For a "fair adaptation"

While the change is global, not all are equally exposed, nor are they equally vulnerable.

Postponing mitigation efforts amounts to throwing on local actors and future generations the costs of an adaptation undergone.

Not anticipating adaptation puts the consequences of inaction on the most vulnerable.

On March 28, 2021 in Nantes, youth demonstration for the climate © Loic Venance / AFP (via The Conversation)

Resilience and adaptation have been strongly criticized for being conservative and socially regressive.

The climate transition must be accompanied by a reflection on the fair sharing of efforts between mitigation and adaptation, between the different stakeholders, between territories and between generations.

Mitigation and adaptation have the same objective: to ensure the resilience of societies and territories in the face of climate change, by preserving the dignity of people, by not degrading their living conditions and by not reducing their well-being (or even improving it). ).

It is urgent ... to accelerate

While the 2015 Paris Agreement set an adaptation objective in its article 7, it is largely neglected.

In France, the record is slim and political support is not up to the challenges.

While the two National Climate Change Adaptation Plans have enabled real progress in the appropriation of adaptation by public decision-makers, if adaptation begins to be integrated locally, in planning, town planning and development documents. 'development, with a commitment that varies depending on the territory, there is still no national adaptation strategy, modeled on the National Low Carbon Strategy, revisable and assessable, which defines targets, management indicators and monitoring.

“CLIMATE WARMING” DOSSIER

The High Council for the Climate (HCC) reiterates that France, despite a reduction in its emissions (but not in its carbon footprint), is not on the right path to achieve carbon neutrality in 2050. We must not only keep the course, but accelerate.

In terms of adaptation, the start is timid.

It is urgent to move up a gear.

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This analysis was written by Magali Reghezza-Zitt, lecturer (authorized to supervise research) in geography at the École Normale Supérieure - PSL with the assistance of Robert Vautard, climatologist and director of the Pierre Simon Laplace Institute of Sciences of the climate.


The original article was published on The Conversation website.

Declaration of interests

Magali Reghezza-Zitt is a member of the High Council for the Climate.

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