In this week's podcast, Chris sits down with Mark Cochrane to discuss global climate change.
Mark is a professor and senior research scientist at the Geospatial Science Center of Excellence (the GSCE) at South Dakota State University. He is also the creator of Peak Prosperity's excellent forum thread on climate change.
In this interview, Chris and Mark explore the science behind the study of climate change, what it tells us, and what steps individuals concerned about the trend can take.
As a scientist, Mark sees an abundance of data that shows the planet is indeed warming. The key questions that concern him are By how much? and How fast?
The whole crux of climate change just comes down to the energy balance of the planet. If things are stable, where we have the same amount of imported energy from the sun and exported energy with the heat, then the climate will be fairly stable, it will be balanced out. If we lose more energy than we gain over a period of time, then the planet would cool and we get things like the Ice Ages that we are familiar with in our past. Conversely, though, if we are gaining more energy than we lose, the planet will warm, like it is doing right now.
Climate change science can sound incredibly complex. But, there are, in fact, just three mechanisms that we could come up with that would cause the planet to warm the way it is.
The first would be, the sun could be getting brighter, providing a bigger energy budget. We have satellites measuring solar radiation very closely and have for decades. We know for a fact the sun is not getting brighter, and we are actually coming out of one of the dimmest periods over the last hundred years, where we have these 11-year sunspot cycles, and we were at a major low in these cycles – it was the lowest in over a hundred years. We should have actually had global cooling over the last decade. Instead, we have had something that has been apparently more flat in terms of global temperatures. But a lot of energy is still accumulating in the oceans.
The second way we could potentially warm the planet, if we were trying to, would be to try to make the planet darker, so thereby we would absorb more solar energy and reduce our albedo tax. So, it is the difference between if you are out barefoot and you step onto white concrete on a hot, sunny day – not so bad. But, if you step onto the blacktop, the asphalt, it is very hot on your feet. So, if we get darker, we would absorb more of the sunlight and turn it into heat. We have been measuring the energy reflecting back off the earth for decades as well, and we know for a fact that the planet is not getting darker. If anything, it is getter brighter, due to the amount of atmospheric haze that we have created through pollution.
The third possible alternative for warming the planet is that, for some reason or other, the rate of energy dissipation, the thermal energy leaving the planet, is slowing down. We are not losing it as fast as we used to. This occurs because of changes in the atmospheric concentrations of the so-called greenhouse gases, things like carbon dioxide, water vapor, methane. When we look at the measurements we have, in fact, the rate of change corresponds very closely with the observed rate of the increase of those gases and the warming that we are experiencing. Measurements, theory and observations all support one another. Anthropogenic greenhouse warming is the only scientific theory that accurately explains what is occurring. We have had over a hundred years of scientists trying to prove this theory wrong, and there is as close to unanimous scientific agreement on this as you ever going to find, with at least 97% consensus among scientists who actually work on the subject.
And, when I mention anthropogenic greenhouse warming as a theory here, I mean that it is a theory that is on par with the theory of gravity or evolution. Scientists are still investigating the nuances and implications of climate change, and the modeling of potential future climate projections is active and a continually developing field of study. But, the existence of ongoing and geologically rapid global climate change is as settled as science gets. There is no remaining scientific debate about the subject. The scientific discussions are only about the rate at which the warming is occurring and what the implications are of this climate change as it happens.
Years of moderating discussion on this topic have taught us that it's a highly sensitive one that people often bring a lot of emotion to, as passionate belief systems operate on many sides of the issue. Civil discourse can often be a challenge.
We've received much urging from readers to have a "broad daylight" discussion on this topic, which is understandable and something we're happy to do. But we realize doing so will likely generate some major differences of opinion, so we ask that comments made below be respectful and in-line with our civility guidelines (i.e., our moderators are on high alert).
Click the play button below to listen to Chris' interview with Mark Cochrane (55m:10s):