Climate change is considered to be one of the most serious environmental threats to sustainable development, with adverse impacts expected on human health, food security, economic activity, natural resources and physical infrastructure. There is solid scientific evidence to suggest that despite the technology improvements as well as other operational and economic measures to reduce greenhouse gas (GHG) emissions, the climate could continue to change, and the potential consequences might be significant.

The likely impacts of climate change (storms, heat waves,etc.) were initially assessed by the Intergovernmental Panel on Climate Change (IPCC) in 1999 and these assessments have since been updated, the most recent one being IPCC’s Fourth Assessment Report issued in 2007. According to the latest IPCC assessments, the impacts of climate change will be felt worldwide (see article Adaptation to Climate Change– Challenges Facing Civil Aviation Stakeholders, Chapter 6 of this report). The need to address the adverse effects of climate change either by mitigation or by adaptation is becoming more pressing.

The articles in Chapter 6 of this report focus on how the changes in climate could affect aviation and the possible areas where aviation might need to adapt its ground and flight operations.


Adaptation — An International Concern

The Bali Action Plan adopted in 2007 at the thirteenth Conference of the Parties (COP13) of the United Nations Framework Convention on Climate Change (UNFCCC), identified “adaptation” as one of the four building blocks (along with mitigation, finance and technology) required for a strengthened future response to climate change. These building blocks are meant to enable the full, effective and sustained implementation of the UNFCCC through long-term cooperative action, from now to beyond 2012.

Most recently, in 2009 at COP15 held in Copenhagen, the UNFCCC Parties stressed the need to establish a comprehensive adaptation programme. It was agreed that enhanced action and international cooperation on adaptation is urgently required and that the developed countries should provide adequate, predictable and sustainable financial resources, technology, and capacity-building to support the implementation of adaptation actions in developing countries. Adaptation to the effects of climate change is now acknowledged as necessary for responding effectively and equitably to the impacts of climate change.



Adaptation versus Mitigation

The terms “adaptation” and “mitigation” describe two actions that are essential in the climate change area. From its beginning, the international climate effort has focused primarily on “mitigation” — reducing GHG emissions to address climate change. However, in recent years, more attention is being given to “adaptation” – adjusting to and dealing with the impacts of climate change. The inset box provides more formal definitions of climate mitigation and adaptation. While mitigation addresses the causes of climate change, adaptation addresses the effects of the consequences. Obviously, better mitigation, because of its proactive nature, reduces risks at an early stage and therefore lessens the need for adaptation. Similarly, early recognition of climate change and anticipation of its impacts will be essential for adjustments in the future. This early preparation will reduce the impacts to any given degree of climate change.


Climate mitigation can be defined as actions taken to stabilize or reduce GHG concentrations in the atmosphere. The IPCC defines mitigation as “an anthropogenic intervention to reduce the sources or enhance the sinks of greenhouse gases”. An example of a typical mitigation measure for aviation would be optimizing the air traffic management systems to enable more direct routings and therefore reducing GHG emissions.

Climate adaptation refers to the ability of a system to adjust to climate change to moderate potential consequences or to manage the consequences of those impacts that cannot be avoided. The IPCC defines adaptation as “adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderate harm or exploits beneficial opportunities”. Successful adaptation can reduce vulnerability by strengthening existing strategies. A typical case of adaptation for aviation would be improvements in coastal area airports’ defences against sea level rise.


Adaptation and Aviation

While drastic reductions in emissions through mitigation measures could stabilize atmospheric GHG concentrations at low levels, it is expected that they will be above the current levels in a few years. With higher concentrations, new phenomena will be observable such as a rise in temperatures and sea level, changes in precipitation, and more extreme weather as shown in Figure 1 (see article Adaptation to Climate Change – Challenges Facing Civil Aviation Stakeholders, Chapter 6 of this report).


Figure 1 IPCC 2007 Summary for Policymakers in Climate Change 2007


Anticipation of and adaptation to these impacts are vital to ensure a reduction in the magnitude of consequences of climate change. The impact of temperature and precipitation changes could increase the demand for cooling for buildings or increase the drainage requirements for runways. These are only some potential effects among others (see article Adapting to Climate Change at Airports, Chapter 6 of this report). Some limitations for ground and flight operations have already been noticed in Europe. These include high wind events, freezing rain, heavy precipitation and lightning strikes (mainly in summer) that can threaten buildings, facilities, and aircraft. Similarly, in winter, there are challenges associated with snow prediction and removal (see article European ATM and Climate Adaptation - A Scoping Study, Chapter 6 of this report).

The impacts of climate change will be more visible in low lying coastal areas in terms of sea levels and storm activities. Infrastructure such as runways and buildings at some airports could be impacted because of rising sea levels (see article Adapting to Climate Change at Airports, Chapter 6 of this report). According to a preliminary review of an OECD Report 5, 64 airports have been identified as likely to be affected by the predicted rise in sea levels. In view of the risks to major coastal cities, as indicated in the IPCC report, flooding and storm activities could impact movement of aircraft and travellers adversely. In addition, possible damage to infrastructure on the air and land side of the airports should be considered. Even though there are some uncertainties about the potential impacts of climate change on aviation operations and related infrastructure, clearly there are challenges that will need to be addressed.


Adaptation to climate risks may take the form of specific actions or projects, for example, construction of a sea wall to protect areas from rising sea levels, or establishment of an early warning system for potential flooding or heat waves. These solutions will require significant investments. States are becoming increasingly aware of the potential risks associated with climate change and will have to incorporate these risks into their future planning, such as for airport development, and design their adaptation strategies accordingly. While ICAO has shepherded improved aviation environmental protection since the 1960s through development of standards and recommended practices, it is aware that additional ambitious mitigation efforts are still needed. The Organization recognized the need to also consider adaptation since the consequences of climate change need to be anticipated and effectively addressed.