Tuesday, November 6, 2007

In a lengthy discussion on The Conscious Earth, an anonymous reader posed the following questions. To avoid cluttering Odiyya’s space with a very lengthy answer, and to foment further discussion, I’ve created space, here.

“ok smart guy explain why i have colder and colder years then huh this summer was a record cool summer and last winter was the coldest in a long time. and if there is so much global warming then when the water gets evaporated where does it go does it just incinerate no i think it goes to clouds so more cloud cover equals cooling down right?

besides you are all missing the point and that point is that God created the earth we are to worship him not the creation. we are straying from him and it will be the end of us all.”

To address your first question:
When climate scientists describe an increase in the global temperature, they are typically describing an average. An average is a method of describing central tendency, or a trend in data. In this case, they are describing both a geographical average and a temporal average.
To calculate the simplest kind of average, we simply add all of the terms together, and then divide this by the total number of terms. For example, if we look at two sets of numbers:
Set 1
A, 19
B, 22
C, 23
D, 22
E, 14

Set 2
AA, 22
BB, 25
CC, 26
DD, 25
EE, 10

For Set 1, the sum of all the terms is 100. If we divide by the total number of terms (5), we find that the average is 20.
For Set 2, the sum is 108. Dividing by the number of terms (again, 5), our average is 21.6.
The average value for the second set is higher than the first, even though one of the terms in the second set is substantially lower than its counterpart in the first set.
We see this in temporal and geographical temperature changes with which you’re already familiar: If you take the temperature in Memphis, TN every day for a year, you’ll find that on average, the temperature in the summer is higher than in the winter. However, there may be a few particularly warm days in the winter when the temperature is higher than on a particularly cool day in the summer. Or you could look at the temperatures in New York City and Dallas, TX. While the average in Dallas will be higher than in New York, there may be days in which it is warmer in New York.
Beyond this, and perhaps more importantly, the Earth's climate is a complex system. There are differences over time (summer is warmer than winter) and from place to place. The Earth's temperature is not equal across its surface, rather there are places at extreme latitudes, high elevations, low elevations, windy places, places near otherwise invisible atmospheric or oceanic currents, &c. Keeping in mind the concept of global and annual averages, it's important to note that many climate models predict that a small number of regions may actually become slightly cooler, even as the average temperature around the world increases. For instance, a NOAA model indicates slightly lower temperatures over the middle of the Sargasso Sea. However, as with the example about averages above, we see that some measurements can move in the opposite direction of the trend. A brief cool period, or a small number of regions with stable or even falling temperatures does not speak for the trend seen across the entire planet.

To answer your second question:
Water does evaporate to form clouds, and clouds do reflect some incoming sunlight. However, there is not a 1:1 relationship between the temperature increase caused by the greenhouse effect and that reflected through the albedo effect. Scientists continue to debate the quantitative relationship between these; this is part of the difference between models that predict a low level of warming, and those that predict higher levels. Also, remember that clouds are not the only features that reflect sunlight. Glaciers and snow-caps also reflect a great deal of light. And as temperatures rise, glaciers and snow-caps shrink.

I presume from your last statement that you’re writing about the relationship between environmentalism and Christian theology. My first question to you is, who suggested that environmentalists “worship” creation? Environmentalists as a group don’t worship the natural sciences or nature any more than NRA-members worship the Second Amendment to the Constitution or hand guns, engineers worship math, or anyone with a savings or retirement account worships money. Anyone who tells you otherwise is simply bearing false witness against his neighbor.
Second, it’s clear that Christians have a religious duty to care for the Earth. The Book of Genesis creates a parallel between the care God has for His people and the care His people are intended to exercise for His fundamentally important gift to them, Creation. Moreover, this gift seems to have been given to everyone, not simply one generation or a few generations of people who choose to consume everything for themselves.
Moving ahead to the teachings of Christ, we are told, “love your neighbor as yourself”. The outcomes that scientists predict from uncontroled global warming will dramatically worsen the quality of life for the world's poorest people. Is it loving behavior to reject warning after warning that we are ultimately risking other peoples’ lives? Is it loving behavior to make the world’s poorest people even poorer?
Environmentalism is not straying from a God-fearing way of life. On the contrary, if Christians take our commission from The Father seriously, or pay any heed to the teachings of Christ, we must work to make a healthy, dignified life for others.

If you have questions, please ask them. If you need time to digest any of this, feel free to take your time.
To readers of The Influence Machine, I am indeed back in the saddle. Please join me, Sue, Panhandle Poet, Progressive, and our readers as we explore topics like the one I've addressed here.