The Intergovernmental Panel on Climate Change is the United Nations body for assessing the science related to climate change. It represents a state of scientific, technical and socio-economic knowledge on climate change, its impacts and future risks, and options for reducing the rate at which climate change is happening.
The Working group II published, on the 22nd February 2022, its contribution to the IPCC Sixth Assessment Report (AR6) which focuses on the impacts, the adaptation and the vulnerability of human societies and ecosystems facing climate change.
Three versions have been uploaded. The first one is the Full report. It covers the impacts of climate change on nature and humanity, and their capacities and limits to adaptation. Its length is over 3500 pages long. The second version is the Technical Summary which provides an extended summary of crucial elements of the report and is 96 pages long. The last version is the Summary for Policymakers[rS1] (SPM) and provides a concise summary of the key findings of the Working Group II report and is 40 pages long.
What is the IPCC?
The Intergovernmental Panel on Climate Change (IPCC) was created in 1988 to produce detailed knowledge on the state of climate change, its causes, its consequences and the possible strategies to avoid it. It is important to note that the IPCC is not an association of physical persons but one of countries. Indeed, its members only represent member countries.
Transparency is a cornerstone element of the IPCC and on the website it is possible to have information on how the authors are selected, on the reference of the diverse studies, how a report is approved and more. IPCC is not a research body but a body that makes a review and a summary of the current knowledge of the matter. There are three working groups and one Task Force.
Moreover, the IPCC does not make concrete recommendations but only projections.
In this tweet, we can see that Dr Masson-Delmotte is correcting, in July 2020, Airfrance’s reference to the IPCC report. The company was stating its desire to compensate for its CO2 emissions by CO2 captations elsewhere.
The IPCC reports are approved by IPCC members but a dialogue shall take place between “those who use the report – the governments – and those who write it – the scientists.”. Hence each member state validates the reports (that are the responsibility of the authors) and each government especially validates the Summary for Policymakers. Hence, each member state, despite diverging interests, approves the following reports.
The scientific papers on which the IPCC reports are done include all work, including those which could challenge the human impact on the climate. Scientific papers have to be peer reviewed to be accepted though. Moreover, the number of scientific studies that are included in the writing of the different reports increased tremendously over time, as the number of climate change documents on the Web of Science did. Indeed, the Working Group II contribution is the synthesis of approximately 34 000 scientific papers.
Human responsibility for global warming is now a consensus.
How is the IPCC report structured?
The IPCC is using a list of terms to give us an idea about the level of likelihood of a certain phenomenon happening (indicated in italic in the reports).
We will here focus on the SPM that hands out the key findings of the Working Group II (WGII) contribution to the AR6 of the IPCC. This report is based on the WGII contribution to the Fifth Assessment Report (AR5) of the IPCC of 2014, and the Working Group I (WGI) contribution to the AR6 cycle.
The key findings of the new IPCC report
Observed Impacts from Climate Change
1: Human-induced climate change, including more frequent and intense extreme events, has caused widespread adverse impacts and related losses and damages to nature and people, beyond natural climate variability. Some development and adaptation efforts have reduced vulnerability.
Across sectors and regions, the most vulnerable people and systems are observed to be disproportionately affected. The rise in weather and climate extremes has led to some irreversible impacts as natural and human systems are pushed beyond their ability to adapt. (High confidence)
Vulnerability and Exposure of Ecosystems and people
2: Vulnerability of ecosystems and people to climate change differs substantially among and within regions (very high confidence). This is due to patterns of intersecting socio-economic development, unsustainable ocean and land use, inequity, marginalisation, historical and ongoing patterns of inequity (high confidence).
Approximately 3.3 to 3.6 billion people live in contexts that are highly vulnerable to climate change (high confidence). A high proportion of species is vulnerable to climate change (high confidence).
Human and ecosystem vulnerability are interdependent (high confidence). Current unsustainable development patterns are increasing the exposure of ecosystems and people to climate hazards (high confidence)
Risks in the near term (2021-2040)
3: Global warming, reaching 1.5ºC in the near-term, would cause unavailable increases in multiple climate hazards and present multiple risks to ecosystems and humans (very high confidence). The level of risk will depend on concurrent near-term trends in vulnerability, exposure, level of socioeconomic development and adaptation (high confidence)
“(b) With every tenth additional degree of global warming, more species will be exposed to potentially dangerous climatic conditions and more biodiversity will be lost.”
World map showing the percentage of species potentially exposed to hazardous climatic conditions according to the average increase in temperature compared to the pre-industrial period.
World map showing the loss of terrestrial and freshwater biodiversity according to the average increase in temperature compared to the pre-industrial period.
World map showing the projected changes in global marine species richness in 2100 compared to 2006, as a function of average temperature rise.
Near-term actions that limit global warming to close to 1.5°C would substantially reduce projected losses and damages related to climate change in human systems and ecosystems, compared to higher warming levels, but cannot eliminate them all (very high confidence)
Mid to Long-term Risks (2041–2100)
4:Beyond 2040 and depending on the level of global warming, climate change will lead to numerous risks to natural and human systems (high confidence). For 127 identified key risks, assessed mid- and long-term impacts are up to multiple times higher than currently observed (high confidence).
The magnitude and rate of climate change and associated risks depend strongly on near-term mitigation and adaptation actions, and projected adverse impacts and related losses and damages escalate with every increment of global warming (very high confidence).
To have a more precise understanding of the lecture on the graph, more information is available on these IPCC graphs explanations.
Complex, Compound and Cascading Risks
5: Climate change impacts and risks are becoming increasingly complex and more difficult to manage. Multiple climate hazards will occur simultaneously, and multiple climatic and non-climatic risks will interact, resulting in compounding overall risk and risks cascading across sectors and regions. Some responses to climate change result in new impacts and risks. (high confidence)
Impacts of Temporary Overshoot
6: If global warming transiently exceeds 1.5°C in the coming decades or later (overshoot), then many human and natural systems will face additional severe risks, compared to remaining below 1.5°C (high confidence). Depending on the magnitude and duration of overshoot, some impacts will cause the release of additional greenhouse gases (medium confidence) and some will be irreversible, even if global warming is reduced (high confidence)
Adaptation Measures and Enabling Conditions
Current Adaptation and its Benefits
Progress in adaptation planning and implementation has been observed across all sectors and regions, generating multiple benefits (very high confidence). However, adaptation progress is unevenly distributed with observed adaptation gaps (high confidence). Many initiatives prioritise immediate and near-term climate risk reduction which reduces the opportunity for transformational adaptation (high confidence).
Future Adaptation Options and their Feasibility
There are feasible and effective adaptation options that can reduce risks to people and nature. The feasibility of implementing adaptation options in the near-term differs across sectors and regions (very high confidence). The effectiveness of adaptation to reduce climate risk is documented for specific contexts, sectors and regions (high confidence) and will decrease with increasing warming (high confidence).
Integrated, multi-sectoral solutions that address social inequities, differentiate responses based on climate risk and cut across systems, increase the feasibility and effectiveness of adaptation in multiple sectors (high confidence).
Limits to Adaptation
There are limits to adaptation and the IPCC report defines two of them. The soft limits to adaptation are the options to face the impacts of climate change that are not currently available due to its costs or technological limitations but might be overcome in the future. Hard limits represent the ones for which existing adaptation options will cease to be effective and additional options are not possible. These hard limitations will increase with climate change (high confidence).
Hard limits to adaptation have been already reached in some ecosystems (high confidence). With increasing global warming, losses and damages will increase and additional human and natural systems will reach adaptation limits (high confidence).
There is increasing evidence of maladaptation across many sectors and regions since the AR5. Maladaptive responses to climate change can create lock-ins of vulnerability, exposure and risks that are difficult and expensive to change and exacerbate existing inequalities. Maladaptation can be avoided by flexible, multi-sectoral, inclusive and long-term planning and implementation of adaptation actions with benefits to many sectors and systems (high confidence).
Enabling conditions are key for implementing, accelerating and sustaining adaptation in human systems and ecosystems. These include political commitment and follow-through, institutional frameworks, policies and instruments with clear goals and priorities, enhanced knowledge on impacts and solutions, mobilisation of and access to adequate financial resources, monitoring and evaluation, and inclusive governance processes (high confidence).
Climate Resilient Development
Conditions for Climate Resilient Development
Evidence of observed impacts, projected risks, levels and trends in vulnerability, and adaptation limits, demonstrate that worldwide climate resilient development action is more urgent than previously assessed in AR5. Comprehensive, effective, and innovative responses can harness synergies and reduce trade-offs between adaptation and mitigation to advance sustainable development (very high confidence).
Enabling Climate Resilient Development
Climate resilient development is enabled when governments, civil society and the private sector make inclusive development choices that prioritise risk reduction, equity and justice, and when decision-making processes, finance and actions are integrated across governance levels, sectors and timeframes (very high confidence).
To facilitate this climate resilient development, international cooperation and governments must work at all levels with the communities, including the traditionally marginalised groups such as women, youth, Indigenous Peoples, local communities and ethnic minorities (high confidence).
Societal choices towards higher Climate resilient development (CRD) in green or lower CRD in red, are the result of decisions and actions and their interactions made by diverse governments, private sectors and civil society actors. The addition of societal choices may shift the global development pathways toward higher or lower CRD. Past conditions have already eliminated some development pathways towards greener CRD (dashed green line).
The CRD merges strategies to adapt to climate change with actions to reduce greenhouse gas emissions; adaptation and mitigation. The CRD involves everyone and aims at improving well-being for all by reducing climate risk, tackling the many inequities and injustices experienced today and rebuilding our relationship with nature.
Climate Resilient Development for Natural and Human Systems
Interactions between changing urban form, exposure and vulnerability can create climate change-induced risks and losses for cities and settlements. However, the global trend of urbanisation also offers a critical opportunity in the near-term, to advance climate resilient development (high confidence). Coastal cities and settlements play an especially important role in advancing climate resilient development (high confidence).
Integrated, inclusive planning and investment in everyday decision-making about urban infrastructure, including social, ecological and grey/physical infrastructures, can significantly increase the adaptive capacity of urban and rural settlements. Equitable outcomes contribute to multiple benefits for health and well-being and ecosystem services, including for Indigenous Peoples, marginalised and vulnerable communities (high confidence).
Safeguarding biodiversity and ecosystems is fundamental to climate resilient development, in light of the threats climate change poses to them and their roles in adaptation and mitigation (very high confidence).
Achieving Climate Resilient Development
It is unequivocal that climate change has already disrupted human and natural systems. Past and current development trends (past emissions, development and climate change) have not advanced global climate resilient development (very high confidence). Societal choices and actions implemented in the next decade determine the extent to which medium- and long-term pathways will deliver higher or lower climate resilient development (high confidence).
Importantly, climate resilient development prospects are increasingly limited if current greenhouse gas emissions do not rapidly decline, especially if 1.5°C global warming is exceeded in the near term (high confidence). These prospects are constrained by past development, emissions and climate change, and enabled by inclusive governance, adequate and appropriate human and technological resources, information, capacities and finance (high confidence).
Despite the urgency of the situation, this report did not receive the media coverage it deserved. Political figures shall read it and integrate it into their programs. Most of the time, it is only done partially or not at all. Without an illumination of their part or a democratic leap pressuring them to act, the situation is stalled. Actions must be taken now to have a chance to limit global warming under 1.5ºC and to improve everybody’s life.
 Risk occurring simultaneously and overlapping
 Overshoot is when the global average temperatures exceed 1.5ºC but then return to that level or below after several decades.