Global Dimming

Do a radio programme always have accurate data - In SA fat chance!!

The % figures quoted seems a bit high, but I live in sunny SA and may not know what is happening in the global part of the world.

I also studied available climate data (±1920 - 1990 and more) for crop water requirement and found some cyclic changes but nothing permanent.

Please consider the following.

Somewheres in the past the earth (or at least a big part of it) was under permanent cloud cover. The earth could have been regarded as a paradise.

At some stage later the system collapsed (due to global cooling) and the water came down as heavy rain. The Skye's were then clear and the rainbow could have been observed.

There are also natural events where dimming occurred (volcano's & meteorites).

Saying the above do not imply that I am in favour air pollution.

Pollution emissions will introduce material in the air that will capture the energy as heat and prevent the sun from reaching the ocean or plants where it is needed too power the activity of filtering out CO2 and produce O2 and save some energy for future generations.

Pollution (air/water/environment) should be reduced to sustainable levels.

As an alternative the population should be reduced.

How to stop or reduce pollution is the question to ask.

Interesting reply.

As to statistics, 46.32% of statistics are made up on the spot!

To say that human activities like vapor trails and power plant emissions can cool or warm the climate of Earth should be good news. It is already too hot in some places and too cold in other places.

I wasn't aware of the pan evaporation studies or the short term climate changes when air flights over the USA were stopped, but those observations confirm that atmospheric moisture and particulates can affect the weather and climate. No one has ever demonstrated that carbon dioxide can do any of the things claimed for it, but we can pretend that it does and alter our activities as if human existence depended on entirely eliminating greenhouse gasses.

I enthusiastically support eliminating all greenhouse gas emissions because I believe it won't make any difference whatsoever in the climate. I also enthusiastically support all efforts to cool or warm the planet as needed with controlled release and extraction of water vapor from the atmosphere.

In its simplest form, we reduce the amount of sunlight on the daylight side of the Earth to keep temperatures down as it has been demonstrated and observed. We also remove cloud cover from the night side of Earth to radiate excess heat into space as it has been demonstrated and observed. With coordinated efforts, we can control rainfall so that it rains when and where we want it and does not rain when and where we don't want it.

No one has ever demonstrated that carbon dioxide can do any of the things claimed for it, but we can pretend that it does and alter our activities as if human existence depended on entirely eliminating greenhouse gasses.

The next time you sit down to eat, find something on your plate that would be there without Carbon Dioxide. Eliminate Carbon Dioxide and you will starve to death. Now let's find the real source of global warming. Put a thermometer in the grass on your lawn and another on the street pavement. Real estate development, not carbon dioxide emissions, is the real culprit, even though that is not politically correct. Take a one acre plot of grass covered land, remove the grass, and build a 25-story skyscraper, (AKA radiator), and see how much more heat you add to the atmosphere.

Look at the recent NASA photographs of the night lights on earth and then consider that most of it has occurred in the past 100 years. There's your global heater. Global dimming was well demonstrated following 9/11 when the ice crystals normally formed by air flow over the upper surface of the wing of high altitude aircraft were eliminated. Drop in pressure on the upper wing surface triggers condensation of water at a temperature will below freezing resulting in fine ice crystals. re-evaporation takes a while.

I will respond to comments to oertg@aol.com

Global dimming actually couter acts global warming. Global dimming causes surface cooling. The effects of global dimming have actually reduced the effects of global warming in the northern hemisphere. Since it is related to the formation of very fine water droplets in the upper atmosphere that act to reflect solar energy into space away from the planet, it helps cool the planet. Adversely water vapor helps trap heat, apparently more effectively than carbon dioxide. Without the fine particles to function as surfaces for the condesation of water in the upper atmosphere, the vapor remains or precipitates out as larger particles are formed that are not stable in the upper atmosphere and fall out. At any rate more heat is trapped, and less incoming energy is reflected. So we need to stop the pollution reduction efforts to remove fine particulate, and produce more fine particulate to drive a global cooling effort.

something else to note about global dimming, the cloud cover/haze helps trap heat from escaping during the night. It not only cooled the daytime, but something not mentioned is the effort of warming the overnight lows on average, It consistently reduced the diference between the lows and the highs driving both towards a more average temperature. So more like 70 degrees f all the time, and less of that 80 in the day 20 at night stuff.

The simple observation that global dimming counteracts global warming is just that. Simplistic. I recently decided to revisit a PBS NOVA video about the subject, which I think occurred after this thread and before I was a member here.

If it were only an issue of counteracting forces, with no other repercussions, it might be little more than of academic note. The NOVA broadcast strongly implies it might already have had severe consequences in real human suffering.

I searched and there are other threads where this subject comes up. But I thought it better to put this link in the thread titled for the subject matter.