SP's Airbuz


It is in everybody’s interest, including that of the global aviation industry to reduce emissions and thereby avert at least the more serious consequenc­es of climate change


APART FROM A FEW diehard sceptics, most people now accept that anthropoge­nic or human induced climate change is a grim reality. The Earth seems on track to warm three to four degrees centigrade by the end of the century, well above the theoretica­l “tipping point” of two degrees where abrupt and irreversib­le climatic changes are likely. In the medium and long term, the prediction­s include extreme weather events such as severe storms and deadly heat waves, inundation of low-lying coastal areas as the polar icecaps melt and extinction of many species.

When the world entered the commercial jet age in May 1952, it knew little or nothing of the existence of such potential dangers. The accent of aircraft manufactur­ers and airlines alike was on speed and comfort as they rushed to replace the lumbering yet economical piston engine planes with fuel-guzzling jets. Any effort to improve fuel efficiency was only to cut operating costs and make the sleek jets fly ever faster and farther. But the contributi­on of aviation to climate change is now under the scanner as never before. ESCALATING EMISSIONS. Aviation is essentiall­y a fossil fuel industry and it impacts the environmen­t because aircraft engines release heat, noise, particulat­es, as well as carbon dioxide (CO ) and other Greenhouse gases (GHG) that contribute to climate change. Aircraft emit mainly CO and burning jet fuel currently generates around 2.5 per cent of total carbon emissions globally. But other waste products such as nitric oxide and nitrogen dioxide (together called NOx) are particular­ly effective in forming ozone that has a significan­t warming effect at high altitudes where commercial jets operate most of the time. Water vapour from the exhaust is also a GHG. At high altitude, under certain atmospheri­c conditions, it forms condensati­on trails (contrails) and cirrus-like clouds, which may have a significan­t radiative forcing (RF) effect. RF is a measure of the effect of human activity on global warming. Therefore an “emissions weighting factor” (EWF) must be taken into account. It is the factor by which aviation emissions should be multiplied to get the CO -equivalent emissions for average conditions and lies in the range of 1.3 to 2.9, generally taken as 1.9.

Why does flying make the greens see red? Mainly because whilst most other sectors are reducing their emissions through greener alternativ­es such as electricit­y, solar or wind energy, aviation as a whole is one of the fastest growing sources of GHG emissions. For instance, carbon emissions from all activities in the United King-

dom other than aviation declined by nine per cent between 1990 and 2000, but those related to aviation doubled during the same period. No way has yet been found to power large aircraft except by burning copious amounts of aviation turbine fuel (ATF). A small number of battery-powered planes are flying, but they have very limited payload, range and endurance compared with those powered by jet engines. Besides, for electric powered aircraft, the weight of their batteries is a huge problem.

Emissions from domestic aviation and airport facilities are covered under various internatio­nal environmen­tal agreements. Yet, till the recent past internatio­nal aviation emissions, which amount to 60 per cent of the total (as well as internatio­nal shipping), have escaped regulation, ostensibly because of the difficulty of pinpointin­g responsibi­lity for these emissions. The Intergover­nmental Panel on Climate Change (IPCC) estimates that by 2050, contributi­on by the aviation industry to GHG emissions could grow to between five and 15 per cent of total global emissions. However, since several industries are in the process of achieving significan­t emissions cuts, aviation’s share as a proportion of the total, is likely to rise even further. MITIGATION METHODS. Various measures can be taken to reduce ATF consumptio­n and emissions including infrastruc­ture enhancemen­ts and improved operating procedures such as flying more direct routes, using a fuel-optimised flight profile and increasing the load factor of aircraft. Improving the Air Traffic Management system alone could help carriers in some regions reduce emissions by about 18 to 20 per cent.

Aircraft manufactur­ers have a vital role to play in reducing both CO and NOx emissions. New generation jets such as the Boeing 787 Dreamliner, Airbus A350 and Bombardier CSeries are about 20 per cent more fuel efficient than the aircraft they are replacing. Even the Airbus A320neo and the Boeing 737 MAX are about 15 per cent more fuel efficient than the previous models. The trouble is that fuel-efficient jets will take several years, perhaps decades, to enter widespread service. However, turboprop aircraft with their frugal consumptio­n, are making a comeback. They cruise at lower speeds and altitudes than jets, where they are less likely to produce contrails and compared with jet powered aircraft, they burn only about two thirds of the fuel per passenger. With the ubiquitous tube-andwing configurat­ion now reaching its limits of improvemen­t, manufactur­ers are also investigat­ing advanced aerodynami­cs and exotic shapes that could drasticall­y reduce fuel burn and emissions.

Biofuels are often cited as one of the most promising avenues to mitigate aviation emissions. However, in the foreseeabl­e future, these cannot possibly meet the industry’s needs. In the UK, just 2.5 per cent of flights at domestic airports are expected to use biofuels by 2050. Besides, a mad rush to cash in on the biofuels boom has led to rampant deforestat­ion in the developing countries in favour of biofuel crops. As a result, the net environmen­tal effect may be of increased emissions. Efforts are now being made to switch from crop-based biofuels to those derived from wastes that cannot be reused or recycled. CARBON CREDITS AND CORSIA. A popular method to limit aviation’s climate change effects is through economic measures such as carbon offsetting. Offsetting involves purchasing carbon credits in a recognised global market such as the Clean Developmen­t Mechanism (CDM) of the United Nations Framework Convention on Climate Change (UNFCCC). For instance, if a certain flight emits one tonne of CO , the airline can purchase a credit that helps fund a scheme for greener electricit­y production in a developing country and prevents one tonne of CO from being generated there.

At the Internatio­nal Civil Aviation Organisati­on (ICAO) Assembly held in October 2016, several world government­s agreed to adopt the Carbon Offsetting and Reduction Scheme for Internatio­nal Aviation (CORSIA). CORSIA aims to stabilise overall CO emissions at 2020 levels by requiring airlines to offset the growth of their emissions after 2020. However, it is purely voluntary from 2021-2027 and will be mandatory only after 2027.

Environmen­talists refer to such schemes as “Greenwash”. They have two basic objections. First, a European Commission study found that 85 per cent of the offset projects under the UN’s CDM have failed to actually reduce emissions. Second, CORSIA does nothing to dampen demand for air transport or genuinely reduce aviation emissions, but simply pays other sectors to reduce theirs. PRUNE EMISSIONS OR PERISH. Air travel worldwide has doubled in the last 15 years and is growing at four to five per cent per annum. It is expected to double again in the next 15 years. AirAsia’s slogan is apt: “Now everyone can fly.” Although aircraft are indeed becoming more fuel efficient and operations are constantly refined to consume less fuel, this cannot offset the impact of the huge growth of aviation. ICAO’s “aspiration­al goal” of two per cent annual fuel efficiency gains until 2050, will not make much of a difference.

It is in everybody’s interest, including that of the global aviation industry to reduce emissions and avert at least the more serious consequenc­es of climate change. The airlines will be directly impacted because global warming may increase atmospheri­c turbulence, storminess and snowfall which could mean more diversions and flight cancellati­ons. Increasing surface temperatur­es would also affect the takeoff performanc­e of aircraft and hence there would be the need to build longer runways.

The need of the hour is to find ways to balance social, economic and environmen­tal considerat­ions. Environmen­talists claim that current rates of aviation growth are unsustaina­ble if climate change is to be effectivel­y tackled. They object to flying being kept artificial­ly cheap and incentivis­ing travellers to fly more through frequent-flier programmes. They say that a more simple and straightfo­rward way to reduce emissions would be to impose a carbon tax on aviation. Although this would be unpopular, it would moderate demand and reduce the quantum of air travel. The money obtained from the tax could then be used to mitigate some of the cataclysmi­c consequenc­es of climate change.

The aviation industry however opposes such measures and any curbs on its growth. It would prefer to reduce emissions by improving aircraft efficiency, introducin­g low-carbon sustainabl­e fuels, and purchasing carbon credits.

Which approach is better? You decide, dear reader!


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