Its no wonder the world's cooling on global warming

[pacharan]

....

What took you so long PJ?

I do concede xoggoths point about there still could be a warming effect from greenhouse gases even though decreased sunspot activity has led to a global cooling.

[pacharan]

Nah it's not. Greenhouse effect was rebranded global warming and was all due to CFC and the loss of the ozone layer above Australia - climate change is the popular/unpopular CO2 effect.

Just making that statement sounds silly - but I suppose Obfuscation / confusion works ey?

I thought the whole CFC thing caused ozone depletion which led to a higher level of harmful solar radiation hitting the earth's surface. Didn't think there was an issue with warming there.

[pjclarke]

I do concede xoggoths point about there still could be a warming effect from greenhouse gases even though decreased sunspot activity has led to a global cooling.

Actually, the relative forcing from solar activity vs greenhouse gases is quite well-known. Turns out, that even if the sun were to get 'stuck' in a Maunder minimum type phase (which hasn't happened), assuming emissions continue unabated, the increasing GHGs would negate the solar effect in just 5 years...

This cyclic solar variability yields a climate forcing change of about 0.3 W/m2 between solar maxima and solar minima. (Although solar irradiance of an area perpendicular to the solar beam is about 1366 W/m2, the absorption of solar energy averaged over day and night and the Earth's surface is about 240 W/m2.) Several analyses have extracted empirical global temperature variations of amplitude about 0.1°C associated with the 10-11 year solar cycle, a magnitude consistent with climate model simulations, but this signal is difficult to disentangle from other causes of global temperature change, including unforced chaotic fluctuations.

The solar minimum forcing is thus about 0.15 W/m2 relative to the mean solar forcing. For comparison, the human-made GHG climate forcing is now increasing at a rate of about 0.3 W/m2 per decade (Hansen & Sato 2004). If the sun were to remain "stuck" in its present minimum for several decades, as has been suggested (e.g., Independent story) in analogy to the solar Maunder Minimum of the seventeenth century, that negative forcing would be balanced by a 5-year increase of GHGs. Thus, in the current era of rapidly increasing GHGs, such solar variations cannot have a substantial impact on long-term global warming trends. Furthermore, recent sighting of the first sunspot of reversed polarity (reported Jan. 4 by, e.g., SpaceWeather.com and NOAA) signifies that the ~ 4-year period of increasing solar irradiance is about to get underway.

NASA, Summary of 2007.

More recently Foster and Rahmstorf (2011) attempted to remove all short-term variation due to ENSO, solar, volcanic influences etc..



Source: http://iopscience.iop.org/1748-9326/...4022/fulltext/

[BlasterBates]

An interesting comment from Prof. Fritz Vahrenholt

Global warming: second thoughts of an environmentalist - Telegraph

[Scoobos]

I thought the whole CFC thing caused ozone depletion which led to a higher level of harmful solar radiation hitting the earth's surface. Didn't think there was an issue with warming there.

Yeah, it was the fact that these rays bounce around once inside , once they are in through the hole; that coined the term "Greenhouse effect"