I have decided that I will here present the case for global warming at such an alarming scale that it warrants unprecedented action by all nations to mitigate a climate and social disaster. Then I will present the case for no reaction. To the best of my knowledge I will stick to the facts and be unbiased. Finally, I will present my own analysis based on these facts. Then (or before) you are invited to weigh in and express your views, analysis, predictions, etc. Hopefully at the end, we will all be a little better educated as to the facts and how we should interpret them.
There are many causes for the earth's atmospheric temperature to change: orbital changes, changes in the gasses in the atmosphere, solar influences, etc. For the last 150 (since the industrial revolution) the average earth's temperature has increased something like 4 to 6 degrees. What are the reasons? On such a short time scale, it is unlikely to be orbital effects. Also, solar activity changes on a quasi periodic scale with predictable results. From uncertain modeling results, and possibly because not much else is left, the change in composition of anthropogenic gasses, most notably trace "greenhouse" gasses seem to be the culprit. If this is the case, then we can probably expect a continued rise in temperature, particularly if the concentration of these gasses continues to increase.
Some scientists and non-scientists have claimed that that the increase in temperature will cause the sea levels to rise and the amount of severe weather to increase. It is certain that there will be changes and that there will be an increase in the sea level. However, as they say, "the devil is in the details". One thing for sure is that the oceans will respond more slowly to the change in atmospheric temperature (except for changes in salinity) because of its high heat capacity. But as the oceans warm, they will continue to release heat fort many, many years as it slowly releases the heat that it has gained.
The major greenhouse gasses and the contribution to the greenhouse effect are i) water vapor (36-70%) and this does NOT include clouds, carbon dioxide (9-26%). ,methane (4-9%), and ozone (3-7%). It is also true that with respect to carbon dioxide, the anthropogenic (as a result of human activity) contributes a small fraction to the total amount of carbon dioxide. We might as well also note that methane is more effective than carbone dioxide. Rotting organic matter and cow “exhaust” are a major contributors to the production of methane. So, we could eat fewer beans and beef for the sake of our environment. Killing all those buffalos in the late 1800s no doubt had a salutary effect on global warming. Burning fossil fuel has contributed ¾ of the increase in carbon dioxide. Presently there are about 385 ppm (parts per million) of carbon dioxide and it contributes to only 0.003% of the earth’s atmosphere.
Warm air can hold more water vapor than cold air. As the air warms, its ability to hold more water vapor increases and since water vapor is an powerful greenhouse gas (even more than carbon dioxide) , the warming accelerates. There are other both positive and negative feedback mechanisms. The bottom line is that the temperature will increase/decrease until there is radiative equilibrium.
Climate models have sought to forecast the apparent warming trend. Forecasts are extrapolations and inherently unstable in time. (How good do you think forecasts are for the next week or two or month? Now, how good do you think they are for 100 years, or 1,000, or 10,000 years).
Who is most responsible for the warming, and what can/should we do about it. Do nations have a responsibility or is it everyone, regardless of political boundaries, or nations?