I always find it interesting when people feel they can summarize a problem or even a solution of enormous magnitude and complexity in a 140 character tweet, or 1 sentence Facebook status update. Far too often we sacrifice accuracy for simplicity. We want a binary reality when it comes to politics so we can feel as informed as possible without having to dive in and understand all these issues. Now, I am not saying we shouldn’t want to know what issues are being discussed and which are relevant for an upcoming election, but far too often the science gets left behind for convenience. Global warming is one such issue. It’s implications are as far reaching as any problem we’ve ever faced, but it has been treated as a non issue in this presidential election cycle.
The earth is getting warmer. There is no intelligent debate saying that it isn’t. The debate comes into play when you ask yourself why, and is it our fault, and is it within reason. The earth goes through cycles of warmer and cooler periods. This cyclical process takes about 100,000 years and has been very stable over the past million years. In this cycle there is about an 80-90 thousand year ice age complimented by a 10-20 thousand year ward period. You can find out more about the natural cycle of earths climate here. There was a recent high point in temperature 8,000 years ago and that marked the beginning of a relatively stable cooling trend. That is, until the industrial revolution.
Since then we have seen a reverse in the expected trend of global cooling. Despite the fact that we shouldn’t be experiencing a global warming trend for another 90,000 years we have found ourselves in a very steep upward trajectory. You can see in the chart below that we have risen quite dramatically in temperature to above the peak temperature in the past warm period. To understand why exactly this is alarming, it is important to know why the earth naturally goes through these cycles in the first place, known as the Milankovitch Cycle. This isn’t a spooky geologically internal phenomenon, this is very straight forward orbital mechanics, since the earth rotates on an axis, it causes our orbit around the sun to ‘wobble’ a little bit. Think of how a top can be spinning very fast, but you will see secondary cyclic motions as a result of that spin, the head of the top might move in a little circle, or the top itself will traverse the table in a circle (assuming the table is flat enough). This is basically what happens to the earth but on an orbital level. This changes our distance from the sun, resulting in a very obvious mechanic to increase or decrease the temperature. We are in a state of moving away from the sun in the cycle, yet our temperature has skyrocketed. That is the root of the issue, and that has been caused by our massive increase of greenhouse gasses and in much the same way our bodies raise in temperature to kill bacteria, the earth is heading for a feedback loop that takes control of this process out of our hands.
note: the multicolored lines are temperatures at various locations that make up the global average (black)