Andrew Stephenson

2016-10-16 14:11:11 -0400

“George Luck commented 14 hours agoThere is an really easy way to make warmists go away. Ask them for actual proof that Co is a green house gas. "I’ll bite.There are a couple of ways of approaching this. First, we can approach this from first principles. What is a greenhouse gas? In its simplest form,a greenhouse gas is merely any gas that absorbs infrared light and converts it to thermal (vibrational or kinetic) energy. Temperature is nothing more than a measure of the average kinetic energy of molecules in a gas, so if the carbon dioxide molecule absorbs a photon of IR light, and starts vibrating, by definition its temperature increases.. That is to say, if you shine infrared light on a bottle full of a greenhouse gas, it will warm up. This is indeed the case for carbon dioxide, which absorbs very strongly at about 2300/cm (associated with “in phase”lengthen/shorten of C=O bonds), and about 650/cm (“flexing” of whole molecule – ie, if the molecule O=C=O, the carbon atom ’bounces" up and down). Simply by being an infrared absorber, it meets the most basic definition of “greenhouse gas”.Scaling up, what does this mean for climatology? Obviously, a cloak of gas around a planet that contains infrared absorbers … will absorb some of the incident light from the Sun, and convert it to thermal energy .. warming the atmosphere. Most critically, how much is absorbed, depends on the concentration of whatever’s absorbing the infrared light. This is something called the Beer-Lambert law, which states, directly, that absorption is directly proportional to the concentration of the substance, and how well it absorbs. You can see this for yourself – put a drop of milk in a glass of water, it turns slightly cloudy. Another drop makes it cloudier, etc. As milk does to visible light in water, so does carbon dioxide to infrared in the atmosphere. Increasing carbon dioxide thus increases infrared absorption.Now we come to the crux of the debate … if, due to increased concentrations of an absorbing substance, the atmosphere is absorbing infrared radiation that was previously being reflected into space .. where is that energy going? The key lies in the ultimate dissipation, which relies on re-readiation of lower-grade infrared from warm ground. This process is strongly dependent on temperature. If you’re absorbing more energy, then you have to re-radiate more to stay in equilibrium … which requires things to be warmer. Secondarily, some of this re-radiation is also held in by atmospheric absorption. By definition, increased infrared absoption, forces the planet to become warmer.That’s the physical principle behind it. Now, does that actually happen?Yes. It does. This is observed directly in several circumstances. Most obviously, Venus’s thick carbon dioxide atmosphere makes that planet hotter than airless Mercury, despite being considerably further from the sun. On Earth. we gain substantial baseline warming from our own greenhouse gases. Water is the dominant influence, but carbon dioxide and methane are also significant contributors. This has been studied ad nauseum. I will not reinvent the wheel and “prove” it directly but here’s a link to an abstract which will help you in your own studies. Unfortunately most of this was done decades ago, prior to the proliferation of open-source journals, so it is paywalled. The link is here: http://www.nature.com/nature/journal/v344/n6266/abs/344529a0.html So… knowing that we already have significant greenhouse effect warming from carbon dioxide, and that basic physics tells us that the proportion of this effect is directly related to carbon dioxide concentrations, we now must realize that … carbon dioxide concentrations are in essence a planetary thermostat – increased levels warm the planet. It’s really that simple. Our observations, both directly and via proxy data from ice cores, agree with this model.This means, then,, that human emissions are problematic from a climatic perspective. isotopic analysis indicates that the observed accumulation is geological rather than biogenic, and there’s only one source of geological carbon dioxide that is anywhere near large enough to have that effect … which is human consumption of fossil fuels.Long story short, we are causing climate change.