Things Your Professor Didn’t Tell You About Climate Change
Davos 2018 is gone, but not forgotten. This year’s World Economic Forum provided yet another opportunity for those who believe in apocalyptic climate change to harangue us about the evils of greenhouse gases amid warnings the world will end in 2050 or 2100 or one of these days when it gets warm enough. Most striking is the annual spectacle of the world’s wealthy and privileged disembarking from their fuel-gulping private jets and limousines or emerging from luxury hotel suites, to proclaim the world must cut back on the use of fossil fuels, or to question why the world’s common people do not feel as deeply or passionately about climate change as they do.
Other than a propensity for believing everything they are told, why are these people so agitated?
If you look at climate change predictions, almost all of them are bad. Critics refer to these views collectively as climate alarmism. Alarmists believe the Earth’s climate is warming because greenhouse gases are being added to the atmosphere through human activities, primarily the burning of fossil fuels. They claim unless the buildup of greenhouse gases is stopped, global temperatures will begin to rise exponentially, which will have terrible consequences, such as major flora and fauna extinctions, coastal inundation caused by melting ice caps, heatwaves, drought, famine, economic collapse, war, and the potential for human extinction.
The basis for many of these predictions are the reports issued by the United Nations Intergovernmental Panel on Climate Change (IPCC). One of the functions of the IPCC is to model the Earth’s climate to predict changes in global temperature. Although the Earth is warming a bit, their models always seem to be more enthusiastic about warming than the Earth appears to be. In fact, a recent study from the UK suggests climate models factor in too much warming.
In science, if a hypothesis is proposed and predictions based on that hypothesis happen as predicted, the hypothesis becomes a theory. If not, the hypothesis is rejected. Not so with global warming. When global temperatures fail to meet the IPCC’s model predictions, they simply move the prediction date out into the future, all the while making it clear the global warming apocalypse is still coming.
Speaking of ominous, in 2006 former vice-president and climate change activist Al Gore claimed:
Unless drastic measures are taken to reduce greenhouse gases in the next ten years, the world will reach a point of no return.
I doubt that point was reached a few weeks ago when I shoveled a surprise blanket of frozen climate change off my driveway. Fortunately, this and many of Gore’s other ominous climate predictions, have not come true.
So, what do we really know?
First, we know the percentage of carbon dioxide and other greenhouse gases in the atmosphere is increasing. Carbon dioxide levels are approximately 45% higher now than they were 150 years ago, likely caused by the burning of fossil fuels during the twentieth century and recent industrialization in Asia.
Even though the present warming trend may be linked to rising amounts of CO2, this is an unproven hypothesis, not settled science. Scientists are still arguing over surface temperature data, including the way it is collected, adjusted, and interpreted; whether CO2 is affecting global temperatures as much as believed; and if water vapor, which humans have no control over, really dominates the greenhouse effect in the Earth’s atmosphere.
Incidentally, the news about carbon dioxide is not all bad. An international study found plant life thriving worldwide thanks to higher CO2 levels.
We know the Sun has a larger effect on the Earth’s climate than anything else. Small changes in solar insolation due to variations in the Sun’s energy output or cyclical variations in the Earth’s orbit, known as the Milankovitch Cycles, can make a big difference in the surface temperature. Yes, greenhouse gasses, ocean currents, volcanic eruptions, and many other things can affect the climate, but the Sun is still the 800 lb. gorilla in the room.
We live in an ice age. Over the last 450,000 years the ‘normal’ average global temperature has been approximately 5 degrees Centigrade cooler than it is today. During that time our climate cycled between long cool periods, known as glacials, which can last 50,000-100,000 years, and shorter warm periods called interglacials, which usually last between 10,000-20,000 years. During glacial periods glaciers and continental ice sheets develop and grow. During interglacial periods, like the one we are experiencing now, the Earth warms and sea level rises as most of the ice melts.
We know, due to the above-mentioned factors and other natural climate oscillations, such as the El Niño Southern Oscillation (ENSO), the 11-year Sunspot Cycle, the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), and perhaps the De Vries Solar Cycle, the world’s climate continually changes. This means the present warming trend could be a natural climate oscillation unrelated to CO2 or possibly a combination of both.
One of those oscillations occurred between 1940 and 1977 as the Earth went through a minor cooling trend, possibly linked to the PDO. This prompted a global cooling scare as scientists feared we were sliding into another glacial period.
We are fairly certain the Earth has been warmer in the past than it is today, perhaps as recently as 950 -1250 AD during the Medieval Warm Period, or 5000-8000 years ago during the Holocene Climatic Optimum, or during the Eemian Interglacial Period around 130,000-125,000 years ago.
We are also certain sea level was higher in the past than it is today. In their 2014 Climate Report the IPCC claims:
Maximum global mean sea level during the last interglacial period (129,000 to 116,000 years ago) was, for several thousand years, at least 5 m higher than present.
So, if the Earth was naturally warmer in the past and sea level was higher, both without extra carbon dioxide in the atmosphere, doesn’t this cast doubt on the CO2 apocalypse?
One item of concern is sea level, which has risen a bit over eight inches since 1880. Alarmists point out roughly ten percent of the world’s population live near the ocean at elevations of ten meters or less, and they present this information as if sea level rise is an imminent threat.
The present accepted rate of sea-level rise is about the thickness of two pennies stacked one on top of the other, around 3 millimeters per year. At this rate, sea level would rise barely 9 inches by 2100, meaning New York City, average elevation 10 meters, would be flooded in a little over 3,000 years. The point is this is a slow-motion process and something we can deal with.
To sum up, there are plenty of reasons to doubt human activities are the sole cause of climate change. If you are feeling anxious or guilty because of alarmist predictions, relax. The climate will continue to warm and cool and it is a good bet Mother Nature will be the one in the driver’s seat. If you still want to be an eco-warrior, recycle, plant a tree, and try to be energy efficient. It is good for the planet.