Context - Climate change is impacting the Earth, bringing a mixture of risks and benefits.
There are two ways of dealing with it: adapting to the changes, (adaptation) or reducing their severity (mitigation).
This is a summary of the contribution of the working group II to the IPCC’s fifth assessment, evaluating various aspects of climate change impacts, adaptation, and vulnerability.
This is a faithful summary of the leading scientific consensus report produced in 2014 by the IPCC : "Climate Change 2014: Impacts, Adaptation, and Vulnerability ".
How are uncertainties handled in this report?
The IPCC uses a very specific language when it comes to expressing the degree of uncertainty or agreement for each statement in the fifth assessment report. For an overview of the specific meaning of each qualifier, you can read the relevant section in our summary of the Working Group I report.
What impacts have already been observed?
Climate change has had clear impacts on natural systems. For instance, changing precipitation and snow and ice melting are altering water resources. This has affected the geographic ranges, seasonal activities, migration patterns and abundance of many species, whether terrestrial, freshwater or marine.
Climate change already has also had some observable impacts on human systems for which we are not well prepared. It has more negative impacts on crop yields than positive ones. The people who are the poorest are also the least able to prepare and adapt, and thus the most vulnerable. However, impacts on human health are so far relatively small.
What are the drivers of climate change-related risk?
The risk of impacts related to climate change results from the interaction between climate-related hazards and the vulnerability and exposure of human and natural systems, which are all driven by changes in both the climate system and socioeconomic processes including adaptation and mitigation.
How is adaptation to climate change implemented?
Throughout history, people and societies have adjusted to climate variability and coped with its extremes with varying degrees of success. Currently, some adaptation processes are being planned but few of them are being implemented.
Climate-change adaptation is an iterative process with multiple feedbacks that require adjustments. There are currently very few assessments of the actions implemented and their effects. The adaptation and mitigation measures (such as CO2 emission reductions) that will be chosen in the near-term will affect the consequences of climate change throughout the 21st century and beyond.
Projections of climate change risks depend heavily on the development pathways considered. For instance, there are less risks and needs for adaptation in pathways where a lot of mitigation actions are taken than where carbon emissions continue to increase.
However, the vulnerability, exposure, and responses of interlinked human and natural systems are difficult to predict.
What are the main risks related to climate change?
The eight main categories of identified risks
|(1) Flooding, storms and sea-level rise in low-lying coastal zones and islands ||5) Food insecurity and breakdown of food production chains |
|(2) Inland flooding in large urban zones. ||(6) Insufficient access to drinking water and lack of irrigation water affecting agriculture |
|(3) Breakdown of infrastructure networks due to extreme weather events ||(7) Loss of marine and coastal ecosystems, their biodiversity and the services they provide |
|(4) Mortality and morbidity during periods of extreme heat ||(8) Loss of terrestrial and inland water ecosystems, their biodiversity and the services they provide. |
Many key risks pose particular challenges for the least developed countries. The precise level of climate change that would trigger abrupt and irreversible change remains uncertain, but the higher the global temperature gets, the more risk there is.
- In urban areas, global risks are concentrated and are expected to affect people, assets, economies, and ecosystems;
- In rural areas, they are expected to disproportionately affect the poorest (such as female-headed households) and those with limited access to land or to modern agriculture, infrastructure and education.
The slowdown in economic growth due to climate change will make poverty reduction more difficult, further erode food security. It will prolong and create poverty traps, particularly in urban areas and hotspots of hunger. Climate change can indirectly increase the risk of violent conflicts, civil war and inter-group violence, by amplifying conflict causes such as poverty and economic shocks.
Increasing efforts to mitigate and adapt to climate change imply an increasing complexity of interactions, particularly between water, energy, land use, and biodiversity, but tools to understand and manage these global interactions remain limited. By reducing climate change through mitigation, the scale of the adaptation needed can be reduced; but under all scenarios of adaptation and mitigation, there are still some risks of adverse impacts.
How can we manage future risks?
A first step towards adaptation to future climate change is reducing vulnerability and exposure to present climate variability. The capacity of social, economic, and environmental systems to cope with climate change is known as resilience. Strategies and actions are currently available to increase this resilience. Prospects for doing so are fundamentally linked to what the world accomplishes in terms of sustainable development through mitigation actions.
Transformations in economic, social, technological, and political decisions and actions can enable climate-resilient pathways. Specific examples are presented in table SPM.1 of the IPCC report.
However, poor planning, overemphasizing short-term outcomes, or failing to sufficiently anticipate consequences can result in maladaptation.