What with the ash cloud and everything, I haven't had time to post about a couple of studies on sustainable aviation that have come out in the last few days.
The first, Flight Path to Sustainable Aviation, was commissioned by Qantas, Air New Zealand, Boeing and Virgin Australia and calls on the Australian and New Zealand governments to help kickstart a local aviation biofuel industry for the region.
Without government assistance, says the report, supply chains will face "technological and market uncertainties" that will limit the investment and expansion needed to enable airlines to purchase alternative fuels.
A similar study, carried out by Sustainable Aviation Fuels Northwest, has pretty much the same message, but for the USA's Pacific Northwest region.
The need for government support to help make aviation more sustainable has been a bit of a theme for me this week.
Yesterday I interviewed Air Transport Action Group executive director Paul Steele, who kept coming back to the same point that "an injection of political will" is what's needed to drive forward the aviation industry's efficiency targets.
So, is it realistic to expect governments to step in and help the industry to reduce its carbon footprint?
Perhaps. In a speech delivered at Georgetown University in Washington DC in March, US President Barack Obama said: "I'm directing the Navy and the Department of Energy and Agriculture to work with the private sector to create advanced biofuels that can power not just fighter jets, but also trucks and commercial airliners."
For more on how the US Air Force is moving towards greening its fleet, see our recent feature, written by my colleague Stephen Trimble.
And if you're interested in finding out more about how algae is progressing as a potential source for aviation fuel, take a look here.
Oh, and the next big thing is expected to be alcohol-derived aviation biofuels, which I plan to find out more about during the Paris air show. Watch this space for a feature on that as soon as I can get it written.