Davin News Server

On Sat, 22 Feb 2025 18:50:10 -0600
AlleyCat <katt@gmail.com> wrote:

> On Sat, 22 Feb 2025 16:40:51 -0800,  Alan says... =20
>=20
> > > Not all, not in the southern hemisphere =20
> >=20
> > But as your own source confirmed the "vast majority" are melting.
> >  =20
>=20
> So?
>=20
> And?
>=20
> Prove man is responsible.
>=20
>

We prolly caused the Hunga Tonga eruption too, in his atrophied mind...

https://judithcurry.com/2024/07/05/hunga-tonga-volcano-impact-on-record-war=
ming/
Tonga volcano prime suspect

Just over a year before the abrupt warming, in January 2022, an extremely u=
nusual volcanic eruption took place in Tonga. How unusual? It was an erupti=
on of VEI 5 explosivity, capable of reaching the stratosphere, which occurs=
 on average every 10 years.

Screen Shot 2024-07-05 at 10.03.01 AM

Figure 12. Time and cone elevation of VEI =E2=89=A55 volcanic eruptions of =
the past 200 years, their distribution by altitude (yellow bars), and the s=
uggested depth for a submarine eruption capable of projecting a large amoun=
t of water to the stratosphere (red line).

There have been a number of eruptions with VEI 5 or higher in the last 200 =
years, although not all of them have affected the global climate. This figu=
re shows with dots the date they occurred and the elevation at which the vo=
lcanic cone was located. The yellow bars show the distribution of eruptions=
 in 500 m elevation bins. The Tonga eruption was a submarine explosion at v=
ery shallow depths, about 150 m below the sea surface. It ejected 150 milli=
on tons of water into the stratosphere.

In our 200 years of records there is only one other submarine eruption with=
 VEI 5, which occurred in 1924 off the Japanese island of Iriomote at a dep=
th of 200 m and did not affect the atmosphere. Only surface effects were ob=
served. NASA scientists believe that the Tonga explosion occurred at the ri=
ght depth to project a lot of water into the stratosphere.[vi] This depth i=
s indicated by the red line. So, the Tonga eruption is a once in 200-year e=
vent, probably less than once in a millennium. Science was very lucky. We a=
re not so lucky.

We know that strong volcanic eruptions, capable of reaching the stratospher=
e, can have a very strong effect on the climate for a few years, and that t=
his effect can be delayed by more than a year. The eruption of Mount Tambor=
a in April 1815 had a global effect on the climate, but it took 15 months f=
or the effect to develop, during the year without a summer of 1816. These d=
elayed effects coincided with the appearance of a veil of sulfate aerosols =
in the Northern Hemisphere atmosphere due to seasonal changes in the global=
 stratospheric circulation.

Screen Shot 2024-07-05 at 10.03.38 AM

Figure 13. Stratospheric water vapor anomaly at 45=C2=B0N.

In this image on the vertical axis, we observe the water vapor anomaly in t=
he stratosphere between 15 and 40 km altitude with ocher tones for negative=
 values and greenish for positive ones. The measurement takes place at 45=
=C2=B0 latitude in the northern hemisphere. On the horizontal axis is the d=
ate, and we can see that the large anomaly created by the Tonga eruption do=
es not appear in the Northern Hemisphere until one year later, in 2023, whe=
n the warming occurred. Thus, there are dynamical events in the stratospher=
e that have the appropriate time lag to coincide with the abrupt warming in=
 2023.

Because the Tonga eruption is unprecedented, there is much about its effect=
s that we do not understand. But we do know that the planetary greenhouse e=
ffect is very sensitive to changes in stratospheric water vapor because, un=
like the troposphere, the stratosphere is very dry and far from greenhouse =
saturation.

As a group of scientists showed in 2010, the effect of changes in stratosph=
eric water vapor is so important that the warming between 2000 and 2009 was=
 reduced by 25% because it decreased by 10%.[vii] And after the Tonga erupt=
ion, it increased by 10% because of the 150 million tons of water released =
into the stratosphere, so we could have experienced much of the warming of =
an entire decade in a single year.

Screen Shot 2024-07-05 at 10.04.30 AM

Figure 14. Global water vapor anomaly above 68hPa.

The stratosphere has already begun to dry out again, but it is a slow proce=
ss that will take many years. In 2023 only 20 million tons of water returne=
d to the troposphere, 13%.[viii]

7. Dismissing natural warming

On the one hand, we have an absolutely unprecedented abrupt warming that th=
e models cannot explain and that has scientists scratching their heads. Suc=
h anomalous warming cannot logically respond to the usual suspects, El Ni=
=C3=B1o, reduced sulfur emissions, or increased CO=E2=82=82, which have bee=
n going on for many decades.

On the other hand, we have an absolutely unprecedented volcanic eruption, t=
he effects of which we cannot know, but which, according to what we know ab=
out the greenhouse effect, should cause significant and abrupt warming.

Of course, we cannot conclude that the warming was caused by the volcano, b=
ut it is clear that it is by far the most likely suspect, and any other can=
didate should have to demonstrate its ability to act abruptly with such mag=
nitude before being seriously considered.

So why do scientists like Gavin Schmidt argue, without evidence or knowledg=
e, that the Tonga volcano could not have been responsible? If the effect we=
re cooling, the volcano would be blamed without a second=E2=80=99s hesitati=
on, but significant natural warming undermines the message that warming is =
the fault of our emissions.