TECH TALK
Figure 2: NBAA Factbook - Global Emissions Chart
These charts will change in the coming years as many industry pundits say that the number of passengers is projected to double over the next two decades. This will challenge not only airlines and operators but the aircraft and engine manufacturers even more so in providing solutions to address climate concerns. ICAO estimates that air transport
is responsible for ~2% of global CO2 emissions, which is comparable to the overall annual emissions of Germany. But aircraft also emit other noxious particles such as are nitric oxide (NO) and nitrogen oxide (NO2), as well as soot and sulfur oxides (SO2), all of which contribute to trapping heat at high altitude and this implicates the industry for ~5% of global warming, according to the Climate Action Network (which is an umbrella group of environmental NGOs).
One statement by Carbon Brief (a UK-based website covering the latest developments in climate science) is notable, “Left unchecked, aviation could contribute over a quarter of the world’s carbon budget by 2050.” Aviation needs to do more as an industry to address all of this.
COMPARISON TO OTHER MODES OF TRAVEL For all of the criticism being heaped upon aviation lately, it is interesting to
14
DOMmagazine.com | dec 2019 jan 2020
see how the sector compares to other modes of transportation. There are many studies by various organizations, so wading through these to fi nd a common set of data was challenging. One of the main fi ndings that can be generalized is that driving generates less greenhouse-gas emissions than fl ying, and domestic fl ights (shorter fl ights) are less fuel- effi cient than cars. Figure 3 shows a comparison of diff erent modes of travel using current mileage estimates. The creator of the chart, Lindsay
Wilson of ShrinkThatFootprint, captured the overall carbon footprint from manufacturing and operations, to provide a more thorough visualization of the carbon footprint of each transportation mode shown. He states, “The major problem with fl ying emissions is not the carbon intensity of fl ying but the great distances covered in short periods. … a return economy fl ight from New York to London is roughly 7,000 miles (11,000 km), a distance comparable to an average driver’s yearly mileage. So the equivalent of a year’s worth of driving emissions can be created in just 15 hours of fl ying. “ He also adds that “Short fl ights (less than 3700 km) are often less carbon- intensive than long fl ights (greater than 3700 km) because they generally have higher occupancy and lighter fuel loads. This doesn’t hold for very short fl ights (less than 1000 km) which are in fact more carbon-intensive as they
Figure 3: Comparison of Carbon Generated by Modes of Travel (Courtesy:
ShrinkThatFootprint.com)
spend little time cruising, and are often not very direct.” The research (which we cherry-
picked only pertinent points relating to aviation only here) visualized in Figure 3 shows the wide disparity in the overall carbon footprint in the primary modes of travel, and aviation needs has more work to do. It can be generalized that long
fl ights are more effi cient than shorter routes since cruising at altitude uses less fuel than taking off and landing. A follow-on to this is that fl ying nonstop is a more economical choice than booking a trip with connections (as if you needed another excuse to try and fl y direct, right?). As Figure 3 shows, modern rail is the most effi cient way to travel, followed by mass transit and alternative transportation technologies, namely electric and hybrid vehicles. Larger aircraft are a long way off
from having electric propulsion systems due to the immaturity of the battery technology, which is needed to drive jet engines, but we may see hybrid solutions much quicker. Rail systems and automotive are ahead in regards to this technology, with modern ferries now going electric
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
