Climate change: its impact on aviation. The time to plan is now.

Summary

• Changes in temperature, precipitation, storm patterns, sea level and wind patterns are the five main ways climate change is expected to affect aviation.
• Temperature change affects aircraft performance, infrastructure and demand patterns. Changed precipitation patterns could increase delays and cancellations.
• More strong storms are expected, with increased schedule disruption. Rising sea levels could reduce airport capacity and cause network disruption.
• Changing wind patterns could increase turbulence, affect journey times and cause disruption.

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Temperature change affects infrastructure, aircraft performance and demand patterns

Europe is experiencing climatic warming at a faster rate than the global average. It has been predicted that some parts of the continent could undergo temperature increases of 4C-5C by the end of the century under a high emissions scenario (according to the Intergovernmental Panel on Climate Change, or IPCC).

Even under the IPCC's medium emissions scenario, a minimum of 2C is expected for most of Europe. The strongest warming is expected in Southern Europe in the summer and in north eastern Europe and Scandinavia in the winter.

In addition to average temperature increases, climate change is leading to a greater range of extreme temperatures.

Increased temperatures have an impact on aircraft performance, for example reducing lift, and this has a knock-on effect on runway length requirements. Aircraft payload and range will also be affected.

Temperature change will have further impacts on infrastructure, such as heating and cooling requirements and heat damage to runways and taxiways.

Change in temperature can also be expected to change demand patterns, both seasonally and geographically.

Changed rain and snowfall patterns could increase delays and cancellations

Europe is expected to experience less rain in the south, but more in the north of the continent. Although snowfall is expected to reduce overall, there will be more heavy precipitation of both rain and snow.

These changed precipitation patterns will lead to delays and cancellations of flights. There are also likely to be increased incidences of flooding of airports and surface access. Changes to snow clearance and de-icing requirements could be a positive if there are fewer occurrences, but this could be offset if those occurrences are more severe.

More strong storms are expected, with increased disruption

As with all things related to climate change, but perhaps even more so, there is much uncertainty in the modelling of storms.

Nevertheless, an increase in the frequency of strong storms is expected, particularly in the autumn and winter on the North Atlantic and in northern and central Europe. In the Mediterranean, there may be fewer tropical-like cyclones, but their intensity may increase.

This will lead to delays, capacity reductions and cancellations, the rerouting of flights and a consequent increase in fuel burn, damage to infrastructure, and an increase in lightning strikes (with possible consequences for aircraft maintenance needs and costs).

Rising sea levels could reduce airport capacity and cause network disruption

As a result of climate change, sea levels in most of Europe are predicted to rise broadly in line with the global average over the longer term.

Under the IPCC medium to low emissions scenario, many parts of Europe are predicted to experience an increase in sea level of more than 0.4 metres by the end of this century (although in the northern Baltic region land is rising and so, sea level increase is reversing).

A rise of 1 metre would put 96 European airports at risk of inundation, according to the European Union Joint Research Centre.

In addition, there could be surges in sea levels resulting from severe storm events, although this is an area of significant uncertainty and regional differences.

Rising sea levels could lead to the loss of airport capacity, either permanently or temporarily, and consequent network disruption. Surface transport links to airports could also be affected.

Prevention of these impacts, such as via enhanced sea defences, airport relocation and the development of secondary airports, will mean increased costs. However, the longer timescales involved with expected rising sea levels allow more time to plan for the necessary actions.

Changing wind patterns could increase turbulence, affect journey times and cause disruption

There is some evidence to indicate that climate change is increasing the variability in the strength, position and shape of the jet stream.

The jet stream is a strong westerly wind (i.e. blowing from the west) of up to 320km/h at an altitude of 5 to 7 miles above the earth's surface - a similar height to that of aircraft crossing the North Atlantic.

The jet stream is important for trans Atlantic flight planning, since it provides a tailwind for aircraft flying from North America to Europe and a headwind for those flying the other way. In addition, changes in the speed and pathway of the jet stream result in air turbulence for aircraft (changes in the jet stream also affect weather patterns below it).

A climate change-induced strengthening of the North Atlantic jet stream is expected to increase both the frequency and strength of clear air turbulence roughly twofold.

It is also expected to reduce eastbound journey times, but to increase westbound trips by a greater amount. This means a lengthening of the average round-trip journey time, a consequent increase in flight time, fuel burn, emissions and costs and challenges in terms of schedule planning, slot management and aircraft holding patterns.

Other expected wind-related changes resulting from climate change are shifts in the direction of prevailing winds and increased vertical wind shear. In addition, there may be increases in extreme wind speeds in the northern parts of central and western Europe, but possible decreases in southern Europe.

In addition to increased clear air turbulence and greater variability in trans Atlantic times and routing, the potential effects of changing wind patterns on aviation include crosswind impacts on airport capacity and operational disruption if winds are too strong.

The aviation industry needs to take actions to adapt to climate change

Clearly, participants will need to train staff in the use of meteorological data and in how to react during disruptions, and will need to increase the sharing of such data with other organisations. This will include greater use of onboard weather detection technology.

The industry needs to adapt schedules, both on a seasonal basis (to cope with changes in demand) and within each day (for example to ensure that larger aircraft can depart at cooler times). Cooling and heating requirements need to be considered in airport terminal design and surface material specifications need to be considered in runway and apron design.

In addition to actions that can be taken now, in all areas where climate change may adversely affect aviation more research is required. This is particularly so in the areas of changing prevailing wind patterns and technologies for the detection of clear air turbulence.

The details of the impacts of climate change on aviation are still fraught with uncertainties. However, it is accepted that the world's climate is changing, and this will undoubtedly pose significant challenges for the entire aviation industry.

The industry has a strategy to mitigate its impact on climate change, although more could be done. However, it currently has a less coordinated approach to mitigating the impact of climate change on aviation.

(See: Aviation's challenging environmental outlook: faster action needed)

Solutions will require the involvement and collaboration of all industry participants, including aircraft operators, airports, air navigation service providers, aircraft manufacturers and regulators.