Climate change, cause and effect, Part 2


Climate change, cause and effect, Part 2

 

In part one, we examined the positive terms, and came up with an estimate of global warming from CO2  from pure physics, making elementary calculations.

The value was about 1.2 degree Celsius by the year 2050. assuming a stable system with adequate negative feedback, but no secondary effects. To see if we can expect more or  less heating we must understand the real mechanisms for climate change.

 

Let us now go on to the negative feedback terms. These are the terms that make the whole system stable if their total sum exceeds that of the sum of the positive terms.

 

1. Pollution acts to absorb more radiation in the atmosphere and have less radiation reach the ground. The net effect is a cooling. A good example of pollution is a volcanic eruption. Dependent of what substance hits the stratosphere we get more or less additional cooling. The ashes can stay aloft for years and prevent radiation from hitting the earth. Historians record “The year without a summer” or as it was also called  “Eighteen hundred and froze to death”  The year 1816 did produce massive crop failures in the Northeastern United StatesNew England, the Canadian Maritimes and Northern Europe. The famine that ensued in those areas was due to the eruption of Mounst Tambora in Indonesia the year before, the largest volcanic eruption in over 1600 years, sending about 100 million tons of sulfur gas into the atmosphere. That decade also featured three other large volcanic eruptions. Around 1970 pollution was the political scare and we all knew that if we didn’t clean up our act a new ice age was going to come within 30 years. Global temperatures were going to be a full ten degrees cooler by the year 2000. One of the proponents of this view was our present Science Presidential Advisor John Holdren. But he was hardly alone. The effort was led politically by Senator Gaylord Nelson. Pollution was the grand theme of the first Earth Day 1970, and the political effort finally led to the Clean Air Act and the Clean Water Act. Through a combination of common sense, scare tactics and self preservation we put scrubbers on our coal plants, reformulated gasoline and diesel fuel and added all kinds of environmental regulations, and – voilà, it got warmer.

 

2. Vegetation is the major reducer of CO2 gases. Since we do not have enough vegetation for the current CO2 production the CO2 levels rise. Loss of vegetation does make this imbalance worse, but this is not the major reason why vegetation is important in the temperature control system. Plants and trees breathe in CO2, and breathe out water vapor.  This is called evapotranpiration and causes increased levels of water vapor in the atmosphere, which we know is a green house gas and gives positive feedback. In addition, wetlands emit huge amounts of methane gas, which is a 25 to 40 times more potent greenhouse gas than CO2.

Wait a minute! This went the wrong way! Vegetation is acting as a temperature destabilizer! Something else, more important must go on or we will never find the terms that make the system stable. So far, all we have found is pollution, but we – cough – know for a host of reasons that is not a path we want to pursue. Enter the

 

3. GAIA effect. Before we go into explaining this let me indulge in a couple of personal anecdotes. Many years ago, around 1977 Dr James Lovelock bought a number of our Gas Chromatographs to set up in the remotest corners of the earth to study pollution and its effect on the climate.  What he found was an unexpectedly large amount of dimethylsulphide (DMS) in the atmosphere, and that acted as a condensation point for cloud formation.  He was a paid consultant for the company I worked for, so he came back a couple of times a year, always willing to hold a seminar for us engineers, and at one of them he sprung “Daisyworld” on us, before it was published, mostly to see if we could poke holes in his hypothesis. It involved a world that consisted of only two flowers, black daisies and white daisies. The computer simulation starts out with a cold world and a weak sun. The sun warms up until suddenly black daisies appear and cover the earth. This warms the earth some more and white daisies appear. As the sun varies in intensity the mix of white and black daisies changes and this keeps the earth at a stable temperature since they have different reflective properties. He then went on to say that the whole earth is like a living organism.

He later presented the paper and the next year we asked him how it was received. “You won’t believe it”, he answered. ”Now there are people that actually believe the earth is a living organism. They demand follow up articles that justifies their belief.” Talking about religion the Mother Earth people now got their goddess, and expressions like. “The earth has a temperature” became commonplace. For me, being a Christian I read with wonderment what God has to say about the Ecosystem. We find this in Genesis 1:6-8 (NIV)

6 And God said, “Let there be an expanse between the waters to separate water from water.” 7 So God made the expanse and separated the water under the expanse from the water above it. And it was so. 8 God called the expanse “sky.” And there was evening, and there was morning—the second day.

The creation story is interesting reading. God takes a whole day out His busy schedule of creation just to create the clouds. In the other five days of creation He adds the statement “And God saw that it was good”, once it was “very good”. Could it be that God knows the ecosystem is fragile and we are going to mess it up beyond repair? Wait a minute! Exactly when was it very good? It was very good after the whole creation was complete, all the components that make up a stable ecosystem was put in place, First then could He finally say: Genesis 1:31 God saw all that he had made, and it was very good. And there was evening, and there was morning—the sixth day.

Let us hurry back to our quest for something other than pollution that acts as a negative feedback to make the temperature system stable. With some newfound anxiety (we are part of the ecosystem, we better understand it) but also assurance we return to the GAIA factor.

Dr Lovelock had found an unusual amount of dimethylsulphide (DMS) in places far from any pollution source. Something else must have put it there. It turns out it is a waste product from phytoplankton, an abundant life form in the oceans, low on the food chain. As ocean temperature rises, phytoplankton levels increase, suggesting a possible feedback mechanism. The DMS molecules act as a condensation kernel for the formation of

4. Clouds. This is something that it is hard to get a grip on. Clouds have a positive feedback as they hold in heat once captured by the earth, but that is more than offset by the large negative feedback that is caused by the albedo factor. The white clouds act as a reflector, and more of the solar energy gets reflected back out into space. This negative feedback factor can be as high as     – 1.9 W m-2/°C.  Whew! Good we found the negative term that could make the system stable. This only says it is possible. Now we have to find out if it is probable or maybe even true.

There are high clouds, Cirrus, Cirrocumulus and Cirrostratus, middle clouds, Altocumulus and Altostratus, low clouds, Stratus, Stratocumulus and Nimbostratus, and then there are clouds that span the heights, Cumulus and Cumulonimbus. There are other clouds but these will do for now. They all have two things in common. They all are the result of oversaturated water vapor, and they all reflect light. How do clouds form, really? Let us take an analogy with boiling water. It boils at the boiling point. If distilled water is used it heats up above the boiling point and erupts in a burst of bubbles that can be quite dangerous. If de-ionized water is used the effect is even more pronounced. The gas bubbles must have a core of something to form from.
It is the same thing with condensation. The air can be super-saturated with moisture and nothing happens unless there is a surface to condensate on. Dust particles, pollen and ions will do fine, but if the air is clean there will be no clouds. Dr Lovelock found the DMS from phytoplankton caused Cumulonimbus clouds in the oceans, from the west coast of Africa dust from the Saharan desert blows into the Atlantic, over landmasses there are always pollen and other pollutants to act as kernels.

Around mountains or ridges clouds always form, and we get clouds associated with weather fronts. So clouds form when the air gets supersaturated with water vapor and have aerosols to form on.

Normally 60 – 70% of the earth is covered with clouds, The Arabs have a saying: All sunshine makes a desert. The deserts (about 8% of the earth) have much less cloud cover, and even when there are clouds it does not rain much. On a tropical island, the morning starts out cloud free, then around noon cumulus clouds form and you get a short rain shower, or maybe a cumulonimbus cloud forms and you get a thunderstorm. In both cases the ecosystem got refreshed, vegetation could grow and allis bliss. They don’t call it an island paradise for nothing. Can we make a desert? We sure can. This was done in Brazil in earlier centuries. They cut down the lush forest in the northeast parts, south of the Amazon, and the nature changed from rainforest to savannah. Thanks to central planning in the Soviet Union a project to increase agriculture in the arid areas southeast of Lake Aral was started. They central planners decided on an irrigation project to harness the two rivers that flow into the lake. The results were catastrophic. Lake Aral is no more, and since there is no evaporation from the lake, sand blows over the irrigated areas, but since the air is dry there are no clouds and certainly no rain, so the rivers went dry too. Millions of people lost their sustenance and had to be resettled. From a temperature control standpoint we lost a temperature stabilizer, and the earth got a little warmer.

Another situation is going on right now: To avoid making the playground for a 4 inch fish a little bit more constrained, we turn off the water to a major part of the California Central Valley.  Note: The fish is not endangered, not even threatened, But we turn off the water to a thriving agricultural community with tomato fields, garlic, cotton and even almond Orchards.

Deliberate deforestation is taking place. Cutting down trees, or in this case just kill them, don’t use them for anything, reduces evapotranspiration, which reduces clouds in the mountains, which reduces the water flow the next season, which turns the whole valley into a desert.  The effect may not be quite so drastic for the ecosystem as a whole, but it did deny 60ooo people their livelihood, while at the same time do drastic damage to the ecosystem, the negative effects of which are yet to be felt.

 

We will talk more about the importance of water in part 4

Are there any other mechanisms by which clouds can form? The answer is yes, and the source is extraterrestrial.

This will be examined further in part 3.

 

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