Global Air-Travel Emissions


The following post by Roger Pielke Jr. noting the projected increase in global air travel provides an eye-opening reason to stuff the cap-and-trade agenda the Senate is supposed to vote on later this month. Making some basic commonsense assumptions here (e.g., that the GDP growth driving this increase in passengers is elsewhere in the world, so that the increase is largely non-U.S. passengers), it seems fair to say that nothing we do to regulate carbon dioxide could have any impact on global emissions thanks to increased air travel from China, India, Mexico, et al. We could kill a million jobs here as no more than an offset for the increase in leisure activities of the tens of millions in the countries taking those jobs.

Boeing’s Eye-popping 2030 Air Travel Forecast

The incredible graph above comes from Boeing’s forecast of air travel to 2030 (PDF). The figure shows that RPKs (revenue passenger kilometers) are projected to increase by a factor of 6 by 2029 from their 1990 values. Boeings’ forecast from 2000 for 2000-2019 underforecast growth in air travel demand.

What is a critical factor for anticipating growth in demand for air travel? Not surprisingly, GDP growth:

Here is what Boeing says about the relationship between GDP and air travel:

Growth in air travel, measured in revenue passenger-kilometers (RPK), has historically outpaced economic growth, represented by GDP, by approximately 1.5 to 2.0 percent. This leads us to conclude that about 60 to 80 percent of air travel growth can be attributed to economic growth, which in turn is driven, in part, by international trade. This is consistent with the observation that countries whose economies are tied to trade tend to have higher rates of air travel. Air travel revenues consistently total about 1 percent of GDP in countries around the world, regardless of the size of the national economy. Globally, air travel has historically trended toward this consistent share of GDP, such that countries that are below or above this level will generally move toward it over the long term.

The remaining 20 to 40 percent of air travel growth results from the stimulation provided by the value travelers place on the speed and convenience that only air travel can offer. For example, travelers value choice of arrival and departure times, routings, nonstop flights, choice of carriers, service class, and fares. Liberalization is the primary driver enabling value creation in the global air transport network. Liberalization typically gives rise to a “bump” in traffic demand. Studies suggest that as the relative openness of a country’s bilateral air service rises from the 20th percentile to the 70th, the resulting increase in traffic can boost air travel demand by an additional 30 percent.

Often, economic growth, induced directly and indirectly by improved air services, creates a virtuous circle that leads to further air transport growth, which in turn leads to added economic growth, and so on.

This suggests some simple logic with straightforward implications:
*Demand for air travel rises with GDP increases
*Increasing GDP leads to increasing emissions
*Policy makers around the world are focused on sustained GDP growth
*New generations of aircraft are expected to be more fuel efficient
*Increased demand will have a much larger than efficiency gains on aviation emissions
*Aviation emissions are going to increase dramatically under this scenario

The inevitable implication of this logic is a need for technological advances in either carbon neutral liquid fuels (e.g., biofuels) or carbon capture and storage. Any other options?


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