The Inconvenient Skeptic: The Comprehensive Guide to the Earth's Climate

by John Kehr

I am a global warming skeptic. I am in fact very skeptical about the whole idea that carbon dioxide (CO2) can cause global warming. The funny part is that I was not always a skeptic. A few short years ago I wasn't a skeptic at all. It was my research into the science of global warming that turned me into a skeptic. The conclusion I reached from my research was that atmospheric CO2 plays a very minor role in regulating the Earth's temperature.

I am skeptical that CO2 played a significant role in causing that change in temperature. So when I say I am skeptical of global warming, I am very specifically discussing the theory that increasing CO2 levels will cause the Earth's temperature to increase. That is the foundation of AGW (Anthropogenic Global Warming). This theory states that humanity is causing the warming that the Earth has recently experienced by increasing the concentration of CO2 in the atmosphere through the burning of fossil fuels. I never intended to write a book about global warming. If you had asked me 4 years ago about global warming I would have answered that CO2 levels would probably make a difference, but the dangers were overstated. In my discussion with many other engineers that is a fairly normal position. It was certainly the view I had before I began my research.

There is simply no place where someone can go to get a good scientific overview of the Earth's climate. That is all I wanted to find, but everything that was available was just arranged as talking points designed to highlight the flaws in the other side's arguments.

perhaps the most important thing that I want readers to gain is an understanding that the Earth is always changing. Not once in the past 50 million years has the Earth's climate stayed the same for any significant amount of time. The third is directly tied to the second one. It is to understand that the Earth will change in the future, no matter what mankind does.

Weather and climate are different. The easiest way to describe the difference is contained in this saying. “Climate is what you expect, weather is what you get.”

Here are some of the basic physical attributes of the Earth (1). Radius: 6371 km (mean), 6378.1 km at equator, 6356.8 at the poles. Total Surface Area = 4π r2 = 510,064,041 km2 148,940,000 km2 of land (29.2% of the surface) 361,132,000 km2 of water (70.8% of the surface) Aphelion: 152,097,701 km (farthest from the sun in its orbit) Perihelion: 147,597,887 km (closest to the sun in its orbit)

Basic physical attributes of the earth.

Temperature Anomaly: The difference between the measured temperature and the average historical temperature.

Temp anomaly: the difference between the measured temperature and the average historical temperature.

Understanding this one simple fact puts a different perspective on the entire topic of global warming.

The seasons on Earth happen because of how the Earth orbits the sun. The main orbital factor that causes seasons is the Earth's tilt. This causes the Northern Hemisphere (NH) and the Southern Hemisphere (SH) to get different amount of sunlight at different times of the year. In December the NH gets much less sunlight than the SH. So the SH has summer while the NH has winter. In June the situation is reversed.

The amount of sunlight the Earth gets is the cause of both cycles that most people are familiar with. Every 24 hours the Earth goes through the day/night cycle. The words dawn, noon, twilight are all used to describe the daily relationship that the Earth has with the Sun. There are also words to describe the yearly relationship with the Sun. Spring, Summer, Autumn and Winter are the words to describe the yearly cycle of the Earth. These seasons are directly caused by changes in the amount of sunlight that the Earth receives.

The NH has more than twice as much land as the SH. Oceans do not change temperature as much as the land does. Since the NH has more land it changes temperature more than the SH.

This is true even though the Earth is closest to the sun in January (at least for the next several hundred years). If the land and oceans warmed up the same then January should be the warmest month. Since it is one of the coldest months of the year, this is the first really big indicator that land plays a much larger role than oceans do in changing the average temperature of the Earth. It is also makes a big difference in WHERE the land is. The SH has very little land around the South Pole. The only large piece of land near the South Pole is Antarctica. That continent is surrounded by water. Since the poles experience the most change in weather from season to season the fact that the South Pole is land surrounded by water is very important. The NH is the opposite. The North Pole is water surrounded by land. So in the summer the land around the North Pole warms up much more than the ocean that surrounds Antarctica. So the NH warms up more in the summer than the SH. The reverse is true in the winter. The land around the North Pole (Asia, North America, and Europe) cools more than the ocean around Antarctica. Illustration 7: Southern Hemisphere is mostly open ocean. That is another part of why the NH has more temperature swing than the SH. It is also why Antarctica remains frozen and also why it has been frozen for such a long time. The water around it does not warm up enough in the summer to cause the air to warm up enough for it to thaw out. While it does warm up by a fair ...

Greenland is the ONLY land north of the Arctic Circle that doesn't have a large landmass to the south of it. It is no surprise then to find that Greenland is the one place that is the most like Antarctica in its climate. Antarctica and Greenland are the two places where there are large permanent ice sheets. Ice sheets are what glaciers grow into when they continue to grow for hundreds of thousands of years. An ice sheet can cover thousands of square miles and be thick enough to cover mountain ranges. Antarctica has had some amount of permanent ice sheets for more than 34 million years now. The only current ice sheets in the NH are in Greenland and they are less than 3 million years old.

The tropics are important because they are the only region of the world that receives large amounts of excess energy from the Sun. This excess energy is the main driving force for the ocean and atmospheric currents. It is the interaction of the ocean currents and the atmosphere that make the Earth livable for humanity. Without the extra energy that the tropics get there would not be enough evaporation to drive the rains and snows that make the continents habitable. The ocean currents also drive the winds. The currents and the winds are what mix the oxygen into the oceans so that sea life can thrive.

Today there are two main methods used to measure the Earth's temperature. The first is what I call station method and the second is called satellite method. Each of them has advantages and disadvantages.

Station Method (3): This is the one that is more familiar to people. It involves a thermometer that is 1.5 meter above the the ground and out of direct sunlight. The high temperature and low temperature each day are averaged for each reading to give the daily average temperature.

Satellite Method (4): This involves a series of satellites in orbit that measure the electromagnetic transmittance of a region of the atmosphere. This is converted into a temperature for that particular region of the atmosphere and averaged over the Earth as a whole. The satellites cover far more of the Earth each day than the stations do, but they don't cover the entire Earth every day, due to the nature of the orbits the satellites are in.

The satellites overall give better resolution to what is going on with the Earth's temperature than the station method does, but the satellite method only went into effect in 1979 while there is somewhat accurate station data going back into the 1800's. How accurate that early data is can be debated: some of it is very accurate, but for most places on the Earth there is almost no accurate temperature data from before 1900.

Unless specifically stated otherwise, the temperature data I use in this book is a combination of two station methods and two satellite methods. Specifically I use the CRU (5), GHCN (6) station methods and the UAH (7) and RSS (8) satellite methods. In this way I incorporate the modern, more sensitive satellite method with the longer period of the station method. So any data past 1979 includes data from all 4 methods. I call the set I use the blended method in the book and on my website to make it clear that is a hybrid temperature set.

The two methods that agree the most are the two satellite methods. The two that agree the least are the CRU and UAH, each from a different method. Those two also happen to be the ones that are most used by warmists and skeptics. I will let you guess which group uses which data set.

Since different groups prefer different temperature sets I tried to use all of them as much as possible. There is one other station set that I did not include that is also commonly used and that is the GISS. I wanted to have 2 of each so I chose the ones that I considered the best of each category and have stuck with that. There is also the HadCRUT which is a version that includes the ocean and the CRU (which is land only), but that method interestingly enough matches the blended set fairly well. So instead of using that one, I use the CRU (the oldest one) and the GHCN for the station.

One of the main factors that cause geography to have such an influence on temperature is the ocean currents. The oceans play a critical role in controlling the Earth's climate because that is how the Earth transports energy from the tropics to the cooler Polar Regions. Anything that alters the flow of energy will have an impact of the climate of the Polar Regions.

Epochs of the Cenozoic

Geologists are the ones that deal with the history of the Earth's changes the most. They have broken that history down into many different names (14). The current era is the Cenozoic and it started 65 million years ago. Geologists picked that point because that was when the Chicxulub asteroid hit the Earth and wiped out ~75% of all species on the Earth (15). That is one of those traumatic events that occasionally happen to the Earth. Just like a car crash can change a person’s life, the beginning of this era started with a large and sudden change to the Earth.

In the beginning of the Cenozoic, the Earth was much warmer than it is today. Most of the past 65 million years has been warmer than today. The current Era started off roughly 8-10 °C (18 °F) (16) warmer than it is now. The major difference in temperature was at the poles. Antarctica had no permanent ice and was probably comparable to Canada as we know it today. The Arctic was probably even warmer than Antarctica.

This is most evident from the climate that existed at the beginning of the Cenozoic. When the era started, there were no glaciers or ice caps on the Earth. Both Polar Regions were too warm for those to exist (17). Today the average Arctic temperature is -14 °C (7 °F) which is warm compared to the average Antarctic temperature which is a stunning -50 °C (-58 °F) (18). When the era started, both regions had average temperatures that were above freezing (19).

The reason that the Polar Regions were warmer is the ocean currents (21). 65 million years ago the ocean currents were able to directly come from the tropics to the poles. The warm water from the tropics helped keep Antarctica and the North Pole warm and prevented permanent ice from developing. There is evidence that the Arctic region was warm enough for at least temperate forms of sea life (22) to live there. It was probably comparable to what the Mediterranean is like today.

Antarctica, which started to cool down. 41 million years ago Antarctica was cold enough for snow and ice to form during the winter. This also coincides with the opening of the Drake Passage between Antarctica and South America. Illustration 16: Drake Passage was closed in the early Cenozoic. The opening of the passage altered the Earth's climate. Over the course of 7 million years the passage continued to open. As the passage became larger it allowed the formation of a new ocean current that is today known as the Antarctic Circumpolar Current (23) (ACC). As the ACC grew in strength, less warmth from the tropics reached Antarctica because the ACC is a current that completely surrounds Antarctica. This changing of the ocean currents resulted in the steady average cooling trend that happened from between 34 to 41 million of years ago. It is important to understand that while the average temperature of the Earth was decreasing, the average drop was caused by a large drop in temperature that was happening in Antarctica. The whole Earth was not getting cooler, Antarctica changed from what was likely a temperate place to a frigid wasteland. Illustration 17: Changing geography plays a major role in changes to the Earth's climate. (Zachos, 2008) A little over 34 million years ago the ACC became strong enough to block the warm tropical currents from reaching Antarctica, when that happened Antarctica started to form the permanent ice sheets that exist today. At the time when Antarcti...

There was one global effect of Antarctica freezing over. That was the drop in the global sea level. The sea levels around the world dropped ~55m as the ice sheets in Antarctica developed 34 million years ago. The effect of the dropping sea level would have been felt around the world. Shallow seas over continental shelves would have disappeared and more land would have been above sea level. So severe was the global impact that the largest species extinction since the time of the dinosaurs occurred. Species that had been separated by oceans were free to colonize new continents much to the detriment of the slower and weaker species. This extinction is called the Eocene-Oligocene extinction (25). Sea level change, species extinction and radical change in the Earth's climate all naturally occurred as a side effect of the change that happened when Antarctica's climate changed. The global effect was significant enough that the time before Antarctica froze is called the Eocene epoch of the current era and the time after is called the Oligocene epoch. It was truly a global change that was caused by a long-term change in ocean currents. This is not to say that Antarctica has stayed the same for the past 34 million years. It has had many periods where glaciers and ice sheets grew, but it has also had many periods when the glaciers and ice sheets were shrinking. That is their natural behavior. For more than 20 million years Antarctica swung back and forth between periods of deep cold ...

It was at this point 2.6 million years ago that the Earth entered its current Ice Age behavior. While the Antarctic ice sheets that had existed in some form for over 30 million years already, it was 2.6 million years ago that the northern hemisphere started to have periods of glaciers advancing and retreating.

Ice Age: A time of extensive glaciation covering vast areas of the earth. Glacial: Is an interval of time within an ice age that is marked by colder temperatures and glacier advances. Interglacial: Is an interval of time within an ice age that is marked by warmer temperatures and glacier retreats. Marks the periods between glacial periods.

By these definitions the Earth is currently in an Ice Age, but experiencing an interglacial period between glacials. Geologists all agree that this is the correct state of the Earth at this time.

Ice Age

Over the past 2.6 million years there have been over 40 glacial/interglacial cycles. Most of these happened when the cycles were short.

In the past 65 million years the average temperature of the Earth has been at least 16 °C (29 °F) warmer than now and 10 °C (18 °F) colder than now. Most of that change has been concentrated in even larger changes in temperature that have taken place in the Polar Regions. One important cause of those changes has been the changing geography of the Earth. The altered geography has had a lasting impact on the ocean currents and that has changed the Earth's climate. During that period of time the oceans have also been at least 150m (500ft) higher and 130m (425ft) lower (28) than they are today. It is safe to say that the Earth changes over time. For anyone that thinks all the change happened millions of years ago, just keep in mind that the lower limit of the sea levels happened a mere 20,000 years ago, a mere blink of time for the Cenozoic Era in which we live.

In the study of past climates, known as paleoclimatology,[1] climate proxies are preserved physical characteristics of the past that stand in for direct measurements (as statistical proxies), to enable scientists to reconstruct the climatic conditions that prevailed during much of the Earth's history. As reliable modern records of climate only began in the 1880s, proxies provide a means for scientists to determine climatic patterns before record-keeping began. Examples of proxies include ice cores, tree rings, sub-fossil pollen, boreholes, corals, lake and ocean sediments, and carbonate speleothems. The character of deposition or rate of growth of the proxies' material has been influenced by the climatic conditions of the time in which they were laid down or grew. Chemical traces produced by climatic changes, such as quantities of particular isotopes, can be recovered from proxies. Some proxies, such as gas bubbles trapped in ice, enable traces of the ancient atmosphere to be recovered and measured directly to provide a history of fluctuations in the composition of the Earth's atmosphere.[2] To produce the most precise results, systematic cross-verification between proxy indicators is necessary for accuracy in readings and record-keeping.[3] Proxies can be combined to produce temperature reconstructions longer than the instrumental temperature record and can inform discussions of global warming. The distribution of proxy records, just like the instrumental record, is strongly non-uniform, with more records in the northern hemisphere.[4]

One of the factors that drive the climate changes over periods of millions of years is the changing geography of the Earth. 50 million years ago there was no Mediterranean Sea. There was a vast ocean from the continent of India to the continental shelf north of the African continent. The portion of the Earth that is now Spain to the Himalayas, were a series of tropical islands surrounded by warm oceans. All of that land has now merged together and the warm oceans and seas that separated them are gone. Only the small Mediterranean remains. Oceans do not have big temperature changes, land does. As the lands merged together to form a large and more continuous land mass, the NH started to experience more significant swings in temperature. A true tipping point was reached 2.6 million YBP when the balance between the landmasses and ocean currents changed enough to initiate the modern ice age. Eventually what is now Siberia will straddle the North Pole in a similar way that Antarctica covers the South Pole. When that happens it is also extremely probable that it will be covered in ice sheets that dwarf those of Antarctica. The current ice ages will be much warmer than what will happen in the future. This will not happen for tens of millions of years, but that is the direction the climate of the Earth is going. Nothing humanity can currently do will change that in the slightest. The changing geography of the Earth is one of those very long-term changes that people cannot see. Thos...

55 million years ago there was the most recent which is known as the Paleocene-Eocene Thermal Maximum (PETM). In a very short period of time the temperature of the Earth increased rapidly (31). While generally the chart may slightly over-estimate the temperatures 55 million years ago, it is possible that the spike in temperature at that point was much, much larger than the chart can show. The Arctic Ocean exceeded 22 °C (32) in this period. There are many theories as to what happened, but there are problems with all of them. All that is really known is that the Earth had a period of very rapid warming and for about 200,000 years the Earth was much warmer than at any other time in the past 65 million years. It isn't a surprise the some warmists have proposed that it was caused by a rapid increase in methane (33) and CO2. I will not speculate as to what triggered the change, but I bring it up only to point out that the Earth also cooled down almost as rapidly as it warmed up. This is a fine example of the Earth staying in balance. Large changes can quickly take place, but something always balances out those changes. That balancing force will be explained later in the book.

With the idea in mind that the Earth's climate will change, it is time to focus on the Earth as it is now. The main focus will primarily be on the last 135,000 years. This will cover two interglacials and one glacial period. Earlier I mentioned that the Earth has longer cycles besides the daily and the yearly ones. That 135,000 year period is the minimum amount of time needed to cover one of the longer cycles that I discussed earlier. I am going to call the longer cycle of the Earth the Climate Cycle. The climate cycle has seasons just like the yearly cycle does. The hardest part to understanding the climate cycle is simply the time scale that it takes for a cycle to happen. The yearly cycle lasts 365.25 days, or 365.25 times longer than the daily cycle. The last climate cycle lasted about 120,000 times longer than the yearly cycle. Thinking of natural cycles that take this long is a challenge, but that is how the Earth has been behaving for the past million years or so. The climate cycle does contain more noise than the yearly cycle, but the similarity between the two cycles is obvious. In the yearly cycle, each point is a single month. In the climate cycle each point is 1,000 years. They are two different cycles operating on very different time scales. It is clear that the Earth has just recently (~15,000 years ago) experienced it's 8th significant warming period in the past 720,000 years (34). Instead of summer in the climate cycle, there is an interglacial. Instead of ...

CLIMATE CYCLES Roughly 150,000 years in length.

The climate cycle has four distinct phases or seasons much like the daily and yearly cycles have. It can be simplified into two phases much like day and night, warm and cold seasons. The warm phase is the interglacial and the cold phase is the glacial. When most people refer to an ice age they are usually discussing what scientists call a glacial.

Duration of each “season” in the different cycles of the Earth.

Any comparison of the temperature trend in the past 100 years is meaningless in comparison to the full scope of the climate cycle. Trends that involve tens of thousands of years cannot be compared to a temperature trend that takes place over 20 years. Such a comparison is absurd in every way.

Another interesting fact is that the Earth was 3-5 °C warmer when CO2 levels were 270-280 ppm. The same level that the Earth has had for the past several thousand years while it has been much cooler than it was during the Eemian. If the CO2 level determines the global temperature, then the Earth was broken during the Eemian interglacial because the current theory doesn't work for the warmth of the Eemian.

The biggest problem that the Eemian presents to the theory of global warming is that it ended. 120,000 years ago the Earth was warmer than it is today by a degree or so. CO2 levels were ~270 ppm at that point. By 115,000 YBP the temperature of the Earth had dropped 4 °C, but CO2 levels were still ~270ppm. The Earth had shown dramatic cooling in a 5,000 year period while CO2 levels remained almost identical to what they had been. Illustration 34: CO2 levels dropped ~8,000 years AFTER the temperature dropped. The cooling could not have been caused by dropping levels of CO2. In all, the global temperature dropped more than 10 °C, while CO2 levels remained constant at ~270ppm. If the greenhouse effect of CO2 is so strong, why did the CO2 level during the Eemian fail to keep the interglacial from ending? Since the CO2 level did not drop until long after the temperature dropped, some other factor must have caused the Earth to cool. How is it possible to correlate CO2 levels to temperature when the range of temperature for given CO2 levels is so broad? That is the only reason why CO2 is associated with temperature change in the past, but the problem is that it only shows a match to temperature change when the Earth is warming. When the Earth is cooling, CO2 stays at the same level while the temperature drops. It is only after the Earth has cooled that CO2 levels start to drop. This should make scientists wonder just how much influence CO2 has on global temperatures. In addition, ...

The Eemian does not exist according to the geological naming system. All the previous cycles are stuffed into a single epoch by the name of Pleistocene. Then the current interglacial is given an epoch all to itself by the name of the Holocene. So the current interglacial is treated in a very different way, even in how it is named. This introduces a bias that this current interglacial is unique, but it is not. It is only from the perception of a human lifetime that the Earth is stable. Geologists are not immune from that bias and certainly in the past there was good reason to suspect that the Holocene was unique, but that is no longer the case.

It is very clear from many different types of proxy data that the Eemian was warmer than the Earth has been during the modern interglacial and the sea levels were also higher during the Eemian. The main methods of reconstructing past temperatures are deep sea cores that measure the oxygen isotope ratios and also ice cores. There are two methods of determining the past temperature from an ice core (49). One is to measure the ratio of heavy and light oxygen atoms in the ice and the other is to measure the ratios of heavy and light hydrogen. Since these are the two components of water there are plenty of both to measure in ice. The ratio of heavy and light oxygen is the standard measurement. Water that is made of the light oxygen evaporates more easily. Water made of the heavy oxygen condenses more easily. This means that the warmer the oceans are near the location of the glaciers or ice sheets, the more heavy oxygen there is in the ice core.

Understanding insolation is important. If you think in terms of light bulbs, then what Milankovic proposed was that changes in the orbit caused long-term changes in the summer and winter insolation over periods of hundreds of thousands of years. If the summer insolation gives 400 W/m2 (4 light bulbs), then the winter will typically give 180 W/ m2 (less than 2 light bulbs). That is why winter is colder. Less light bulbs of power from the sun. The long-term orbital changes cause the winter and summer insolation to change over time. So if the summer right now is 400 W/m2, 5,000 years from now the summer could be 380 W/m2 while winter could be 200 W/m2. In this case the total energy stays the same, but the winter would be warmer and the summer colder. It is these long-term changes in insolation that drive the glacial-interglacial cycle.

Winter is colder in the NH because it gets less energy for a shorter period of time. Summer gets more energy for a longer period of time. This energy difference is the entire and complete cause for cold winters, warm summers, chilly mornings and warm afternoons. It entirely causes all aspects of the daily and yearly cycles of the Earth.