By Richard Bleil
Editorial Note: This topic was recommended by a friend.
The Earth is warming, and polar ice is melting significantly faster than expected. As the ice melts, the ocean rise. As oceans rise, there is more water so…why do droughts still occur?
Before delving into that, let us explore climate change and if human activity can have a global effect. The first hole in the Ozone Layer was reported in 1985 over the south pole. It is an oscillatory occurrence at its worst in the first South Pole “thaw”. See, the South Pole ice cap is on land that is significantly higher than the North Pole. It’s like a polar winter in the mountains, and as such, is much colder than the North Pole winters. Special ice clouds occur that are generally only seen in the winter over the South Pole, which is believed to absorb chlorine free radicals and accumulate them as the adsorb onto the ice. In the thaw, the ozone depleting chlorine is released suddenly, depleting the ozone that is naturally thinnest at the poles to begin with since it primarily is formed at during electrical storms at the equator and diffuses towards the poles.
Every year, NASA monitors this ozone hole, which recently has become large enough to reach populated land in South America. Two more ozone holes have been discovered since; the first, of course, over the North Pole as might be expected. The third, as it turns out, was briefly over New York City. There is no way to explain this third ozone layer hole except for human activity.
So back to the question at hand. As the polar ice caps melt, sea levels can be expected to rise (up to 9 inches in the most drastic estimates with more conservative estimates at 3), so more water will be available. But, let’s be real; the globe won’t be covered in water. Less than a half foot of sea level rise will primarily cause coastal flooding, affecting sea-front property and maybe some additional flood-plane problems. Don’t get me wrong; this flooding will cost billions or perhaps trillions of dollars worth of damage, which provides the economic argument for stopping global warming.
So if flooding isn’t the problem, the question becomes what effect global warming will have. To understand this, we have to understand the water cycle. You know this; you’ve learned it and it is logical if you think about it anyway. Water vapor condenses into water droplets, forming clouds and eventually rain which is absorbed by the ground, plants, animals, and makes its way into streams, lakes and rivers and eventually to the ocean. Eventually, it evaporates, and becomes water vapor again, and the cycle continues.
This is all well and good, but where does all of this happen? It makes most sense that water will evaporate the most where the earth is warmest, namely, the equator (hence the thunderstorms and ozone production). Here, water is evaporating the heaviest, and diffuses towards the poles. As the water vapor reaches the cooler regions of the Earth, it re condenses and rains. Where it rains, you will also have evaporation, which will reach the upper atmosphere, and diffuse, again, towards the poles, until it reaches a cooler climate, condenses and rains again.
If you look at a globe, you’ll see bands of desert and temperate weather. These bands occur where, on average, the rain passes over (having evaporated but not yet cool enough to condense) and where it falls (the temperature is cool enough from where it evaporated to condense and fall). The US government plots these band and makes recommendations for farmers to plant based on what crops need little water, what crops need a lot of water and those that are in between.
As the Earth warms, it can be anticipated that water vapor will have to travel further to reach a region cool enough to re condense and fall again. This means that these desert regions can be expected to begin to move northward, which indeed they have as shown by these crop recommendations. So as this occurs, regions that had experienced good rain historically (and hence the average rainfall is moderate to high) may begin to experience desertification, and the average rainfall will falter. Conversely, some regions that were historically desert and low rainfall regions may suddenly have significant average rainfall resulting in flooding.
And here we are, with portions of the country flooding, and others suffering drought. This might just be a bad year, but such extreme weather can be anticipated to increase, I’m afraid, as the weather seeks a “new normal”.