The sky’s bright blue right now, which is weird because I am
looking up through a 5,000-metre thick plume of volcanic ash from
Iceland. This has stopped all flights in the UK air space and much
of northern Europe.
(As somebody quipped on the radio, `Dear Iceland, we said send
CASH’.)
So there are no vapour condensation trails from jets, which
prompts the thought: did anybody ever figure out what con trails do
to the climate?
One study estimated that the 3-day shutdown in US aviation
after 9/11 increased diurnal temperature range by 1C!
Another study in the Journal of Climate in 2004 concluded
that:
It is concluded that the U.S. cirrus
trends are most likely due to air traffic
and
the cirrus trends over the United States
are estimated to cause a tropospheric warming of 0.2-0.3C [per]
decade
That’s huge. Anybody know if these studies still hold up?