I'm a believer that, in order to dismiss something out-of-hand, you need to have proved the opposite. In this case, the possibility that the weather system will react in such a way that it doesn't lead to catastrophe hasn't been disproved. After all, it has kept temps between liveable bounds as the sun has increased it's strength. So the very understandable worry concerning the highest concentration of CO2 that's been in the atmos since the 1st humans left the Savannah ~ xxxx years ago, becomes a risk assessment.
- CO2 could be the cause - but not necessarily...circumstantial evidence
- CAGW...It is well known that most of that warming is NOT due to the direct warming effect of the CO2 by itself, which is relatively weak. It is instead due to indirect effects (positive feedbacks) that amplify the small amount of direct warming from the CO2. The most important warmth-amplifying feedbacks in climate models are clouds and water vapor.....
- thus CO2 warming is tripled
I shall end with some statements often heard:-
- "Never has the world warmed so much so fast"
- When people perceive that scientists agree on catastrophic climate change, they’re more likely to support the need to prevent it
- 97% scientific consensus - a large number of sceptics (particularly the atmospheric researchers) agree that the additional co2 will cause some warming with a question of 'how much?' and 'will it be permanent?'.
the effect of atmospheric molecular collision processes on radiation transfer is not taken into account. Since the current atmospheric concentration of carbon dioxide is only 360 parts per million, almost all the collisions which carbon dioxide molecules experience are with oxygen or nitrogen. We know from studies of vibrational- translational energy transfer (vibrational relaxation) studies which go back some fifty years, that under atmospheric conditions most of the spectrally-excited molecular vibrations of carbon dioxide will be quenched and the excess energy transferred to translational energy for oxygen and nitrogen.
"sensitivity"? every doubling of CO2 = n deg C of warming? - fn of T, ppm? Lag in the system....dependency on other factors...coupling...any stress factors?
CAGW ..assumes that this kind of natural cloud variability does not exist, and that the Earth stays in a perpetual state of radiative balance that has only been recently disrupted by mankind’s greenhouse gas emissions.
Robert E. Stevenson, Ph.D.
subjects related to climate scale variations in the oceans and marine atmosphere, in both time and space. These were
- (1) Large-Scale Ocean Circulation,
- (2) Decadal and Interdecadal Variations in the Oceans,
- (3) Carbon Dioxide in the Ocean,
- (4) Air-Sea-Ice Interactions and High Latitude Ocean Processes, and
- (5) Ocean-Atmosphere Coupling and the Tropical Ocean and Global Atmosphere.
But all it would take is a small change in global average (or Northern Hemispheric average) cloudiness to cause global warming. Unfortunately, our global observations of cloudiness have not been complete or accurate enough to document such a change…until recently.
Such a cloud change would cause the climate system to go through natural fluctuations in average temperature for extended periods of time.
the warming in the 1920s and 1930s led to media reports of decreasing sea ice cover, Arctic and Greenland temperatures just as warm as today, and the opening up of the Northwest Passage in 1939 and 1940.
While the PDO is primarily a geographic rearrangement in atmospheric and oceanic circulation patterns in the North Pacific, it is well known that such regional changes can also influence weather patterns over much larger areas, for instance North America or the entire Northern Hemisphere (which is, by the way, the region over which the vast majority of global warming has occurred).
"...But it also means that the radiative forcing caused by increasing atmospheric concentrations of CO2 is not sufficient to cause PAST warming, either. So, this then leaves a critical unanswered question: What has caused the warming seen over the last 100 years or so?
Here I present new evidence that most of the warming could be the result of a natural cycle in cloud cover forced by a well-known mode of natural climate variability: the Pacific Decadal Oscillation (PDO). While the PDO is primarily a geographic rearrangement in atmospheric and oceanic circulation patterns in the North Pacific, it is well known that such regional changes can also influence weather patterns over much larger areas, for instance North America or the entire Northern Hemisphere (which is, by the way, the region over which the vast majority of global warming has occurred).
To demonstrate this physical interpretation, I modified the simple climate model of Spencer and Braswell (2008) to include an atmosphere, an ocean mixed layer, and a deeper ocean layer which slowly exchanges heat with the mixed layer. (These modifications were added one by one, as necessary, to explain characteristics of the satellite data which could not be expalined without those modifications.) The model was driven by radiative and non-radiative forcings that varied randomly in time, having a time scale of days to weeks. The radiative forcing only directly affects the ocean mixed layer, as might be expected with variations in low cloud cover causing varying amounts of absorbed sunlight by the ocean.
Others have noted that the warming in the 1920s and 1930s led to media reports of decreasing sea ice cover, Arctic and Greenland temperatures just as warm as today, and the opening up of the Northwest Passage in 1939 and 1940.
"The goal of Skeptical Science is to explain what peer reviewed science has to say about global warming."