AoC number

246

Primary domain

ENV

Secondary domain

AP

Description

Global average surface temperatures have risen at an average rate of 0.13°F per decade since 1901. Since the late 1970s, however, the United States has warmed at nearly twice the global rate. Worldwide, 2000–2009 was the warmest decade on record, and existing heat records are being surpassed year after year. Complicating the issue is the fact that the causes of this warming are hotly disputed and not well understood. Although manmade greenhouse gas emissions are widely acknowledged as a contributing factor to climate change, controversy has emerged over the extent of their involvement. A report by Dr. John R. Christy for the U.S. Senate accused existing climate models of overestimating the impact of greenhouse gases, citing balloon and satellite temperature data that showed warming of only 0.3-0.4°C total, rather than the 1°C suggested by the models. In general, 102 IPCC models typically predict 2.5x the temperature rise.
In practice, warming atmospheric temperatures make it more difficult for aircraft to maintain lift, and the effects are already being felt. In June 2017, a heat wave in Phoenix, Arizona grounded over forty flights, and similar cases are likely to occur as temperatures rise. Fokker faced similar issues when America West operated F70 out of Phoenix, forcing them to make an AFM addendum making operations until 53 °C possible. Furthermore, as air density and lift generation decline, a recent study suggests that between 10% and 30% of fully-loaded aircraft will have to reduce their weight loads to take off. Airports at lower elevations with denser air, such as JFK or Charles de Gaulle, will be less impacted. Some, including Dr. Richard Lindzen, argue that climate dangers to aviation are minimal, since aircraft are designed to withstand ambient tempartures up to 15°C above average and few operate in areas that would require load reduction. However, due to the fact that multiple flights have been impacted by rising temperatures already, the risks of climate change must still be considered.

Potential hazard

  1. Heat waves
  2. Increased precipitation duration and intensity
  3. More frequent and intensified winds and storms
  4. Rising sea levels and ocean acidity levels affecting operations of sea level airports, on average 1-1.5 mm/year.
  5. Changed bird migration routes

Corroborating sources and comments

Numerous studies on climate changes

Source: US EPA (http://www.epa.gov/climatechange)

Proceedings of the National Academy of Sciences: http://www.pnas.org/content/early/2010/06/04/1003187107.full.pdf+html

http://www.nsf.gov/news/news_summ.jsp?cntn_id=114961

http://www.nsf.gov/news/news_summ.jsp?cntn_id=111511

http://www.nsf.gov/news/news_summ.jsp?cntn_id=105692 https://www.wired.com/story/phoenix-flights-canceled-heat/

There are a number of studies suggesting that global warming may not be as great as estimated. Several are listed below:

A Climate of Doubt about Global Warming (Environmental Geosciences, Volume 7 Issue 4, pp. 213, December 2000)- Robert C. Balling Jr.

A comparison of tropical temperature trends with model predictions (PDF) (International Journal of Climatology, Volume 28, Issue 13, pp. 1693-1701, December 2007)- David H. Douglass, John R. Christy, Benjamin D. Pearson, S. Fred Singer

Analysis of trends in the variability of daily and monthly historical temperature measurements (PDF)(Climate Research, Volume 10, Number 1, pp. 27-33, April 1998)- Patrick J. Michaels, Robert C. Balling Jr, Russell S. Vose, Paul C. Knappenberger

Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming^l(Nature Geoscience, Volume 2, 576-580, July 2009)- Richard E. Zeebe, James C. Zachos, Gerald R. Dickens

Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming^l(Nature Geoscience, Volume 2, 576-580, July 2009)- Richard E. Zeebe, James C. Zachos, Gerald R. Dickens

Documentation of uncertainties and biases associated with surface temperature measurement sites for climate change assessment (PDF)(Bulletin of the American Meteorological Society, Volume 88, Number 6, pp. 913-928, June 2007)- Roger A. Pielke Sr. et al.

Environmental Effects of Increased Atmospheric Carbon Dioxide (PDF)^l(Journal of American Physicians and Surgeons, Volume 12, Number 3, pp. 79-90, Fall 2007)^l- Arthur B. Robinson, Noah E. Robinson, Willie H. Soon

Implications of the Secondary Role of Carbon Dioxide and Methane Forcing in Climate Change: Past, Present, and Future (PDF)^l(Physical Geography, Volume 28, Number 2, pp. 97-125, March 2007), Willie H. Soon

https://m.phys.org/news/2017-07-surging-limit-aircraft-takeoffs-globally.html (Rising temperatures due to global warming will make it harder for many aircraft around the world to take off in coming decades. During the hottest parts of the day, 10 to 30 percent of fully loaded planes may have to remove some fuel, cargo or passengers, or else wait for cooler hours to fly, the study concludes.) https://wattsupwiththat.com/2017/02/25/richard-lindzen-petition-to-president-trump-withdraw-from-the-un-convention-on-climate-change/ (Dissenting opinion by Dr. Lindzen, backed by 300 other scientists of various disciplines.) Comments from Evert Jesse: You know of course that we are not at all convinced of the catastrophic effects of climate change, but even under the more extreme scenarios the effect of this on world air transport will be quite limited. Main arguments for this are the following:

1. Current air transport has only a small fraction actually operating in conditions where payload/range may be limited, because the aircraft are already designed for unusual conditions: engines are generally rated (=deliver full thrust) for ambient temperatures 15°C higher than average.

2. The average temperature rise predicted by the climate models is about 0.3°C per decade. This means that in 30 years’ time the average world temperature would have increased by 1°C. Actual rates are much lower: about 0.1°C per decade.

3. In 30 years’ time a new generation aircraft will be available, which would of course be optimized to the new ambient conditions if these would prove to be materially different from now.

4. Sea level increase: at the moment, according to official figures from NOAA (National Oceanic and Atmospheric Administration) the sea level rises with 1.7 to 1.8 mm per year. No recent acceleration of this trend has been detected by NOAA. In the quoted 30 year period this means a sea-level rise of 5 cm. Due to the high thermal inertia of the ocean mass an acceleration of this rate will be very slow, giving ample time to move or protect the airports: Schiphol airport is situated about 4 m below sea-level.

Incidentally, many respected scientists do not accept the more alarmist predictions of the global temperature increase…. We think therefore that for strategic decisions it would be wise to watch developments on this front, but not act prematurely. The probability that nothing unusual is going to happen seems high, otherwise fundamental changes will develop quite slowly due to the thermal inertia of the oceans, which provide a huge damper on climate changes.

Last update

2017-08-28