Calls for Shipping and Aviation to Do More to Cut Emissions

[robert99]

http://www.nytimes.com/2016/04/17/science/calls-for-shipping-and-aviation-to-do-more-to-cut-emissions.html
Both industries are expected to grow over the next few decades, and their percentages of worldwide emissions may increase significantly as emissions are reduced elsewhere. Environmental groups say steps the industries have already taken, including regulations to reduce emissions from new aircraft and ships, will not help much because they are tied to baselines for improvement that are too low.

Yet after being included in initial drafts of the climate treaty, a paragraph on limiting or reducing emissions from the two industries was eliminated from the final version, which was agreed upon in Paris in mid-December.

(have wondered how 1 million barrels of aviation fuel being burned up everyday in the atmosphere for decades effects the environment - World Jet Fuel Consumption by Year (Thousand Barrels per Day) )

 

[Andy_T]

I see this as another effort to distract the general public from the little known fact (little known or accepted by the general public, that is) that animal agriculture accounts for more emissions than all transportation together....

 

[Blobbenstein]

I see this as another effort to distract the general public from the little known fact (little known or accepted by the general public, that is) that animal agriculture accounts for more emissions than all transportation together....

1 million barrels of aviation fuel being burned up everyday

I dunno Andy, that's quite a lot of aviation fuel just so people can have their picture taken at the Sphinx etc.

 

[robert99]

This was interesting (not sure about the science though)
Data suggests Global Temperature tracks Aviation Fuel Consumption
The trouble is that global water vapor concentration is difficult to measure and even harder to pin on humans. However since WWII humans have been conducting a great atmospheric seeding experiment. Thousands of large flying machines have been circling the earth day and night releasing millions of tons of water vapor into the upper atmosphere. The fuel used is typically kerosene (C12H26); when a molecule of kerosene burns in oxygen we ideally get twelve molecules of carbon dioxide and thirteen molecules of water vapor and a bunch of heat.
We can see the consumption was less than two million barrels/day in 1984 and has risen to about five million barrels/day in 2010. The growth rate since about 2004 has been modest due to significant improvements in airliner efficiency. In the next figure the GISS global temperature has been plotted against the aviation fuel consumption. The correlation is quite good, better in fact than that for carbon dioxide. So if we all stop flying will we save the earth? Maybe, maybe not, as correlation alone does not necessarily imply causality but we do have a viable hypothesis, water vapor is a significant greenhouse gas and we are injecting vast quantities of it into the atmosphere via air travel. The temperature hiatus (if it is a hiatus) is explained by lower consumption and emissions due to more efficient jet engines. If this mechanism were correct and we did stop emitting water vapor then the atmospheric water vapor would soon reach a lower equilibrium and the temperature should fall back.
It is interesting to speculate what might happen if we do back the wrong gas. We shut down our fossil systems; coal-fired power stations, hydrocarbon based transportation and replace these with say renewable or nuclear energy and develop a “green” hydrogen economy producing nothing but “clean” water vapor. We would stop our CO2 emissions but vastly increase our water vapor output. This could actually make the earth warmer so we must make sure we get it right. The right answer is not known, more real science is needed with all hypotheses on the table.

more at Greenhouse Gas Pollution in the Stratosphere Due to Increasing Airplane Traffic, Effects On the Environment