Research and analysis

Key points and questions: IPCC Working Group II report on impacts, adaptation and vulnerability

Published 31 March 2014

The UN’s Inter-Governmental Panel on Climate Change (IPCC) published the second volume of its 5th Assessment Report on Climate Change: Impacts, Adaptation and Vulnerability in Yohohama, Japan on 31 March 2014. The report was finalised after a six day meeting attended by delegates from over 100 countries and a number of the Report’s expert authors.

The IPCC’s first report on the Physical Science Basis of Climate Change was published in September 2013. It showed clearly that climate change is happening now and greenhouse gas emissions from human activities are the dominant cause. This new report shows how climate change is already having an impact on the natural environment and man. It warns that increasing magnitudes of warming will increase the likelihood of severe, pervasive, and irreversible impacts in the future. It assesses how climate change impacts and risks can be reduced and managed through adaptation and mitigation.

This is the most significant report on the topic since the IPCC’s 4th Assessment Report in 2007. It has been prepared over the last four years by 310 experts from across the world who reached their conclusions by reviewing thousands of published research papers. It has undergone peer review by many other scientists, experts and by IPCC member governments. The thoroughness of the process is without parallel in terms of scope, rigour, transparency and level of government engagement.

1. What are the key headline findings from the report?

  • Climate change is already having an impact on ecosystems and man on all continents and across the oceans. Evidence has grown since the last IPCC report.

  • As sea levels rise, coastal communities worldwide will experience ever more flooding, coastal erosion and submergence. Species face extinction and the ocean is warming and acidifying.

  • Unmitigated climate change poses great risks to human health, global food security, and economic development.

  • Urgent action to reduce emissions is essential to avoid dangerous climate change. The level of adaptation required is dependent on the scale of mitigation.

  • Adaptation is essential to deal with the risks of climate change but there are limits to what adaptation alone can achieve.

2. What sorts of impacts are we already seeing?

The report identifies many impacts that have already been seen, these include:

  • Terrestrial and marine species have shifted their geographical ranges and migration patterns;

  • In many regions rainfall patterns have changed, snow and ice are melting, glaciers are shrinking, and permafrost is thawing.

  • Trees and forests have been seen to die back, corals are declining, ice is melting and some species have become extinct.

  • Global aggregate production of wheat and maize has already been negatively impacted.

3. What are the main risks from climate change?

The risks from future climate change are significant with potentially severe impacts across all regions and many sectors. Key risks include:

  • A growing number of land and freshwater species face an increased extinction risk;

  • Coastal systems and low-lying areas will increasingly experience adverse impacts such as submergence, coastal flooding, and coastal erosion as sea levels rise;

  • Ocean acidification will pose substantial risks to marine ecosystems, especially polar ecosystems and coral reefs, if we do not reduce emissions to low levels;

  • Under low levels of warming, without adaptation the overall production of major crops (wheat, rice, and maize) is projected to reduce, although individual locations may benefit;

  • Climate change is projected to increase displacement of people and may amplify common drivers of conflicts, such as poverty and economic shocks;

  • Climate change will exacerbate existing human health problems and lead to increases in ill-health in many regions for example, through likelihood of disease, increased heat waves and fires;

  • Climate change impacts are projected to slow down economic growth and make poverty reduction more difficult.

4. What does the report tell us about responding to climate change?

Climate change poses significant risks however through good risk management we can avoid the worst impacts. The report confirms:

  • A combination of adaptation and mitigation will reduce the scale of the risk however, some risks will be unavoidable.

  • Recent extreme storms, flooding, heat-waves and droughts demonstrate that we are already vulnerable to climate and weather events

  • We need to act now. Actions and choices taken in the early part of this century will shape the risks we face in the latter part of the century.

  • Early action will allow more time to adapt to impacts but there are limits to adaptation. Some risks will remain so we cannot rely on adaptation alone.

  • Climate change will affect everyone. Poor and wealthy countries, rural and urban populations alike, must plan for the future and adapt to limit future risks.

5. What are the implications of climate change for the UK?

The IPCC didn’t focus on individual countries. It did however identify three key risks from climate change for Europe:

  • Increased economic losses and more people affected by flooding in river basins and coasts, as urbanisation continues, sea levels rise and peak river flows increase;

  • Increased water restrictions. Significant reduction in water availability from river abstraction and from groundwater resources combined with increased water demand (e.g. for irrigation, energy and industry and domestic use);

  • Increased economic losses and people affected by extreme heat events: impacts on health and well-being, labour productivity, crop production and air quality

These findings align well with the UK’s own Climate Change Risk Assessment (CCRA) published in 2012, which identified that the biggest challenges in the UK will be flooding and water shortage.

High levels of adaptation can significantly reduce these risks but does not remove them.

6. What are the costs of the impacts and adaptation?

  • Global economic impacts from climate change are difficult to estimate due to the complexity of the many variables they are trying to capture.

  • It is recognised that economic impact estimates do not fully consider all factors and are likely to underestimate true costs. Nonetheless scientists agree that the economic losses due to climate impacts will get increasingly large as warming increases.

  • Similarly there are significant challenges in trying to assess global adaptation costs and further research is needed. Limited evidence indicates a gap between global adaptation needs and the funds available for adaptation.

7. What has changed since the last report?

  • From its last major review of six years ago, it provides a strengthened body of evidence on observed impacts and future risks of climate change.

  • Compared to previous reports, the report assesses a substantially larger base of scientific, technical, and socio-economic literature; the number of scientific publications has more than doubled between 2005 and 2010.

  • It considers how mitigation and adaptation actions can help us reduce and manage the risks we face, capitalise on any potential beneficial changes and maximise co-benefits of measures to tackle climate change, such as improved air quality. This focus on risks is new since the last report and makes the report very valuable to governments and policy makers.

8. Is this the IPCC’s main report?

This is the second of three major IPCC reports in the 5th Assessment Report Series. The IPCC’s first report on the Physical Science Basis of Climate Change was published in September 2013. The third report, an assessment of the options for reducing emissions through mitigation measures, will be published on 13 April 2014. All these reports will be wrapped into a synthesis report to be published in October 2014.

  • Details on what the government is doing to tackle climate change can be found on GOV.UK

  • There is also a wealth of valuable information and handy tips on how to reduce your own energy consumption and lead a greener life on the Energy Saving Trust website

  • More details about the IPCC reports can be found on the IPCC website.