On 17/02/2016 08:40, JCW wrote:
On Tuesday, 16 February 2016 22:58:27 UTC, Martin Brown wrote:

[snip]

There certainly could be some effect since a highly active sun can fluff
up the outer atmosphere and increases drag on satellites. It is also
very slightly brighter by 0.1% when active despite having dark sunspots
it also has bright faculae which occupy a much larger area.

A Dalton minimum-type possibility, eh?

There is always a slight possibility of anything.

There is some evidence that the solar dynamo is weakening and if it
drops below a certain threshold then sunspots will become rarer.

I noted that, Martin. There's more than enough evidence from the qualified scientific community supporting climate change.

Less evidence, yet, to show direct correlation to sun cycles and more work to be done I think?
But gladly accept pointers to sources where this may not be do!

There is a slight correlation about +/-0.1% in solar luminosity ~1W/m^2
with the solar sunspot cycle brighter with an active sun, and also some
still slightly circumstantial evidence that UV emissions increase more
strongly with an active sun and make the Earth's atmosphere fluff up and
retain heat slightly better. The TSI records from satellites show the
slight variation in total solar irradiance over the 11 year cycle.

http://www.acrim.com/

There is always room for more research on the solar variability. We
would be in severe trouble if the suns luminosity changed abruptly!

Here is one such study from GISS

http://www.giss.nasa.gov/research/briefs/rind_03/

Even if there was a low sunspot cycle coming for #25, would the signal be over ridden
in any event by what's happening with our climate?

That tipping point they talk about isn't that far away it seems, if it's not here already?

TBH I am fairly sceptical of claims about tipping points although it
could be that the world's chaotic climate will at some point jump to
another attractor and then we get different climates in some places.

If it happens then hysteresis means that the planet will have to cool by
quite a long way before it will jump back to our present state.

Meanwhile, the "weather" will continue to bounce around and vary cold/hot in the short term.....

That is sort of the meaning of weather. The only certainty is that a
warmer atmosphere and a prevailing wind coming in over warmer oceans
means more precipitation in the highlands. Prepare for more flooding.

--
Regards,
Martin Brown