The 2 per cent aviation emissions figure Cathay Pacific Mark Watson cites (“Aviation industry is committed to addressing climate change impact”, June 20) in response to my letter (“Emissions accelerating, not declining”, June 13) differ from the 3-3.5 per cent cited by the International Civil Aviation Organisation (ICAO) website.
The ICAO’s projected aircraft emissions growth of 3-4 per cent per year contrasts with Mr Watson’s planned halving of emissions by 2050. In 38 years, a 3.5 per cent exponential growth will quadruple, not halve, current emissions: 628 million tonnes of carbon dioxide (CO2) annually will become 2,512 million tonnes. Because aircraft engines release CO2, nitrogen oxides (NOx) and particulates into the stratosphere, their impact is amplified. Current contrail-generated cirrus clouds insulate the atmosphere adding an independent warming effect greater than all previous aircraft CO2/NOX emissions since we began flying. Also, the 70 per cent of improvement in aircraft fuel efficiency has already been achieved. To “radically reduce” that remaining 30 per cent of emissions is technically increasingly difficult.
Any future efficiency improvements are offset by the doubling of flights projected by the Airport Authority (advert in this paper on June 21). I quote: “HK’s GDP forecast at compound annual growth rate (CAGR) of 3.4 per cent” (GDP doubles in 20 years); “Mainland’s CAGR at 7 per cent” (an unrealistic quadruple GDP increase over 38 years); “Air traffic demand doubling by 2030”, coincidentally, a 3.5 per cent annualised growth in demand. Where is this growth to come from? Cheap extractable oil, without which these growth projections are unfeasible, is almost exhausted.
If the authority’s growth projections are correct, aircraft emissions will rise exponentially, making climate change a major problem – or peak oil will terminate the 20th century infinite-economic-growth/business-as-usual model, making flying prohibitively expensive, thereby killing demand. Thus, a third runway either adds to climate change or is redundant.
Richard Fielding, Pok Fu Lam
Letters to Editor SCMP