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Post by Xenos the ElderA friend of my was telling me that the permafrost in Siberia is melting
and this will release huge amounts of methane.
Methane being much worse for global warming.
Siberian permafrost (as is Alaskan and Canadian) is indeed melting.
Methane is, on a per molecule basis, a stronger greenhouse gas than
CO2 or water vapor. But: a) it isn't a guarantee that the permafrost
melting is going to release large quantities of methane b) if it did,
it isn't obvious that the methane will stay in the atmosphere long. --
Methane is readily oxidized by O2 and OH into CO2 and H2O, weaker
(per molecule) greenhouse gases, the latter of which rains out.
The fate and role of methane in the atmosphere is a serious question,
see my site for a faq on it with references, and even more so, see
http://www.ipcc.ch/
Post by Xenos the ElderWhat about the gulf stream being 30% weaker?
What about it? The gulf stream isn't, currently, 30% weaker than at
other observed times. Europe, though, needn't be very concerned about
the Gulf Stream. It is the North Atlantic Current (in part, fed by the
GS) which keeps Europe warm.
Post by Xenos the ElderOr 1/3 of the ice of the North Pole has melted already.
There a lot of garbling going on about the arctic ice pack. First,
be sure the reference is to the arctic ice pack. 'The north pole' usually
means statements regaring a few square meters near somebody's ship or
ice camp near the pole. Well, no surprise that the ice pack breaks up
and melts some in the summer -- even at the north pole. That 30% of
the area especially near the north pole becomes ice free in late summer
is no great suprise, nor climate change marker. It refreezes in the winter.
The arctic ice pack -- summer minimum extent -- is indeed experiencing
a decline over the period of record, about 2% per decade, possibly
accelerating in more recent years. With ca. 25 years of observations,
this is a 5% or so decrease. See http://polar.ncep.noaa.gov/seaice/Analyses.html
for current observations and http://polar.ncep.noaa.gov/seaice/Historical.html
for information more focused on climatology and history.
Post by Xenos the ElderMore fresh water coming from Siberian rivers and so further diluting the
salt content thus endangering the pump which keeps the gulf stream going.
Siberian rivers have always* fed water into the arctic. In part, it
is this which helps maintain the sea ice cover the arctic does have.
In the 1970s, a serious concern in the literature was whether the then-planned
Soviet river diversions would reduce the fresh water flow into the Arctic
enough to melt the ice pack. -- The fresh water forms a cold (exposed to the
cold atmosphere) stable layer over the warmer, but saltier deeper parts of
the Arctic. This is a thin layer, so could be eliminated by relatively small
changes. That would mean less ice in the Arctic.
Less ice forming in the Arctic means less ice melting in the nordic seas,
which helps destabilizing the column, which _strengthens_ the sinking on that
end of the conveyor belt, and _increases_ the flow of the North Atlantic
current.
More fresh water from Siberia, however, likely does not lead to the reverse
feedback. The Arctic can only freeze so much area, and it does already all freeze
in the winter. Fresher water, or more fresh water, doesn't make for thicker
freezing.
Again, though, it's North Atlantic Current, not Gulf Stream. And it isn't
clear that the Siberian river runoff really has had the intuitively expected
effects. It may, and it's something folks are watching. More important, though,
seems to be atmospheric circulation driving more or less ice out of the
Arctic and in to the Nordic Seas.
*always = last 12 ky or so, since the deglaciation was well under way.
Asking is good. Reading more is better -- again, see my web pages and
the IPCC site above. Many of the kind of question you have are addressed.
In most cases, we don't have absolute final answers, and those are indicated.
Post by Xenos the ElderWill the amount of carbon dioxide not increase in the future because of
Chinas and India's growing economy.
Depends on how they get their energy and how they use it. Dollars of
GDP do not correlate especially well to energy use, nor does energy use
correlate well to CO2 emissions. The US uses 2-4 times the energy per
dollar of GDP than the other 'industrial' countries do. The US also
gets most of its energy from fossil fuels, which gives it a high
kg_CO2/kW ratio compared to places, like France, which get most of
their energy from nuclear.
Business as usual certainly suggests, though, that as their economies
grow, they'll emit more greenhouse gases. It'll be a long time before
they catch the US on ghg emissions, though. They'll pass the US economy
in GDP first, at their current efficiencies (of $ per kW, and kg_CO2/kW).
--
Robert Grumbine http://www.radix.net/~bobg/ Science faqs and amateur activities notes and links.
Sagredo (Galileo Galilei) "You present these recondite matters with too much
evidence and ease; this great facility makes them less appreciated than they
would be had they been presented in a more abstruse manner." Two New Sciences