Too much hype has been going on around the media and the Catholic blogosphere in regards to global warming. The potential effect of increased human activity on climate change carries many consequences that quickly turn this issue into a political one. One of the main ramifications is the possible increased regulation of fossil fuel production and consumption, which for a carbon-based global economy, can heavily affect economic activities as we know them today.
As Catholics, we cannot fall into political partisanship, but fulfill our divine responsibility in protecting the environment. Sadly, we have seen the former in main Catholic blogs, rather than an informed approach and a genuine interest in the issue. The starting point for all of us in this issue is to understand what is global warming, its potential causes, and a path forward. This is what I attempt to include in this post, which will be divided in two parts: the first will deal with the basics of the earth’s energy balance and the greenhouse effect and the second will touch on the results of the latest study published by the Intergovernmental Panel on Climate Change.
Disclaimer
As a Chemical Engineer, I had to take several courses on chemistry, kinetics, thermodynamics, mass transfer, and organic and physical chemistry, so I know a thing or two about these things. I will touch mainly on energy balances on this post, which I happen to deal with every day in my job responsibilities. However, I’m not a metereologist or a climatologist and they are the ones who have the final word. Hence, I will talk about their data and conclusions on my second post. What I present here and on this post are not my personal views, but I would still encourage you to do your own study and read reliable scientific sources on the topic that do not have any political affiliation and that deal with the different positions on global warming.
Put Al Gore aside
We have written much about the Holy See’s position on global warming (here and here) and the Nuncio’s call to Catholics to take personal responsibility in this issue by working less, spending less, and wanting less. Firstly, let us learn the mechanics of the earth’s heat balance and then let us dig into the available data and determine whether human activity is a direct cause of global warming. In order to begin the discussion, let us forget about Al Gore for a second. We have mentioned how Christian truths contained in Catholic teaching, and in this case, the concern of caring for God’s creation, can be found in ideals of the liberal wing just as they can be found in the conservative wing. As a result, we should not start talking about what Gore “thinks,” but what the challenge of global warming represents for us as Christians.
Thermodynamics 101
Before we start talking about how greenhouse gases trap heat and, in return, heat the Earth, let us talk about energy balances. As we were taught to memorize in Engineering, the first law of thermodynamics states that energy cannot be created or destroyed, but only transformed. What does that mean? Basically, it means that energy simply does not disappear into thin air—it is transformed. For instance, when you run for a mile, you will sweat and emit body heat. You are not creating that energy (heat), but transforming the energy stored in your body in the form of nutrients (calories) into motion (mechanical energy), and then into heat, which finally is released into the atmosphere. Of course this is a small contribution of energy, but for our purposes, just understand that the energy goes somewhere to be transformed into another form of energy–it does not just disappear.
Think of a large concert hall where you are by yourself, because you got there early to watch the show. The air conditioner in the hall is set at 70 deg F and it turns on and off in order to maintain that temperature and right now you are feeling quite comfortable. Minutes later, more people start to come in and before you even know, the hall is filled with over a thousand people. The air conditioner is still set at 70 deg F, but now you need to take the concert brochure out and turn it into a fan, because you are getting a bit hot. What is happening in this hypothetical situation is that the air conditioner is now turning on more often in order to keep the temperature down, due to the increased body heat emitted from the increased number of people. It feels hot now, because the A/C has a limited capacity (in BTUs) that can “remove” the energy (heat). Therefore, if a thousand more people enter the concert hall, you will feel even more uncomfortable, because the air conditioner capacity is not large enough to keep up with the increased generation of energy in the hall even if it remains on the entire time. Hopefully, if the engineers of the concert hall did their job correctly, they designed the air conditioner big enough to handle the maximum capacity of people in the hall.
The Earth’s Energy Balance
Similar analogy of the concert hall and the air conditioner applies to the earth. Think of the the atmosphere as the air conditioner and the concert hall as the surface of the earth. However, the atmosphere, different from the air conditioner, does not release cool air, but filters radiation from the sun instead, preventing the earth’s surface from getting too warm.
The earth has a natural energy balance that allows life to exist. We know now from history that whenever that energy balance is affected in any way, the earth surface cools or warms up, which has led to ice ages, for instance, and explains why certain species have disappeared, such as the dinosaurs. The controversy around global warming is that in the past this energy balance has been affected by natural elements and that the subtle warming the earth is experiencing now may be affected by an unprecedented new element: human activity.
Similar questions arise as with the air conditioner and concert hall example. In theoretical terms and for the sake of the analogy with the given example, we can ask: Is the atmosphere designed with enough “capacity” to handle the increase in energy generated by natural processes and human activity?
What is the “greenhouse effect”?
The surface temperature of the sun has been estimated to be anywhere from 5600-6000 deg C (10,000-11,000 deg F). Think of those pictures you used to see in your grade school textbooks of the sun sending radiation to the Earth. If you still have any doubts of how hot radiation from the sun can be, stand out in the sun in the summer time at noon for about an hour somewhere in the Gulf coast or if you can make it to the Equator, even better. In any case, thanks to the atmospheric layers, the surface of the Earth does not see extremely high temperatures radiating from the sun even if sometimes it feels like it is 200 deg F outside! Think of the atmosphere as a filter, or even a shield. The atmosphere reflects some of that radiation coming from the sun back to space, but the rest of it is absorbed in the atmosphere or makes it through to the surface of the earth. Just as we mentioned that energy cannot be created nor destroyed, but transformed, natural processes on the surface of the earth (e.g. water vapor from oceans or other bodies of water) generate heat that rises to the atmosphere. On this second step, the atmosphere does the same thing than with the radiation coming from the sun: it lets some portion of the radiation pass through into space and the rest is absorbed by the atmosphere. Let us recapitulate:
1. Radiation comes from the sun to the earth.
2. The earth’s atmospheric layers reflect some of the heat coming from the sun into space and the rest goes through to the earth surface.
3. Natural infrared radiation generated on the earth’s surface rises to the atmosphere.
4. This radiation either passes through the atmospheric layers into space or is absorbed.
Now our attention turns to that infrared radiation coming from the Earth that is trapped in the atmosphere. Keep in mind, that this is a natural process and that this infrared radiation is a normal part of the earth’s thermodynamic balance. That same trapped heat in the atmosphere warms up the gas molecules which in turn, release heat back to the earth—these gases are called “greenhouse gases.”
What are greenhouse gases?
The atmosphere is made up of a combination of gases: 78% nitrogen, 21% oxygen, and the remaining 1% is composed of carbon dioxide, methane, hydrogen, and inert gases such as argon, neon, helium, and neon. The extent to which certain gas molecules alter the balance of incoming and outgoing energy between the Earth and the atmosphere is called Radiative Forcing. The gases that have a greater positive radiative forcing tend to warm the Earth’s surface, whereas those gases with a negative radiative forcing tend to cool the earth’s surface. Of the gases that make up the atmosphere, carbon dioxide has the highest radiative forcing, which means that it tends to warm the surface of the earth the most. 
There are three major greenhouse gases: carbon dioxide (CO2), methane (CH4), water vapor (H2O), and nitrous oxide (NO2). If you remember your chemistry and biology correctly, you will know that these gases occur naturally on the earth and are even byproducts of natural processes such as combustion, photosynthesis, fermentation, and more. What is the big deal then around greenhouse gases? The issue at hand is that we are seeing concentration levels of these gases in the atmosphere—especially carbon dioxide—in unprecedented levels and scientists believe that this is due to increased human activity, because of its exponential increase in post-Industrial times (see Figure from Intergovernmental Panel on Climate Change).
For Christians around the world, the question becomes: if we are seeing that concentration levels of CO2 have increased dramatically since the Industrial Revolution and we are being told by scientists that this can cause an increased heat release to the earth… do we sit and say that this is all a myth constructed by the far Left? Or do we attempt to understand the problem at hand and do something about it?
On Part 2:
– Conclusions from the Intergovernmental Panel on Climate Change
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