Human Impact - Part Two
IMPORTANT NOTE: THE TEST YOU WILL BE TAKING ON 12/11/17 WILL COVER EVERYTHING CONTAINED IN THIS SECTION OF THE ONLINE TEXTBOOK, INCLUDING LINKS THAT ARE CONTAINED IN THE TEXT AND THE STUDY LINKS LISTED AT THE END OF THE TEXT.
In Part One, you got a broad overview of how humans have impacted the environment. Now, in Part Two, we'll take a deeper dive into the ways humans have caused changes to the environment, how those changes threaten life itself, and why there are some who deny human involvement.
As part of our Human Impact curriculum, you were assigned group projects using Google Slides. There were a total of nine different topics assigned:
- Solid Waste
- Ocean Pollution
- Freshwater Pollution
- Air Pollution
- Ocean Acidification
- Deforestation
- Habitat Destruction
- Climate Change - Temperature
- Climate Change - Extreme Weather
You will find links to these slideshows at the end of this unit of the Online Textbook. Please familiarize yourself with each of the topics.
Climate Change - Some Background
We know that the climate on Earth has not always been the same. There have been times when the Earth was in an Ice Age, and very cold. Other times, it has been hotter. Precipitation patterns, too, have changed over time. Some places that are deserts today were once tropical rainforests, or even covered by oceans. None of these facts are in dispute except, perhaps, by people who believe that the Earth is only 6,000 years old.
It's important to know a little bit of history here. Scientists have long known that CO2 is a byproduct of the combustion (burning) of fossil fuels. As early as the 1800s, some scientists were concerned that increasing the amount of CO2 in the atmosphere would make the planet warmer. This is known as the greenhouse effect. But even into the 1950s, scientists were not concerned about adding CO2 to the atmosphere, because it was believed that CO2 eventually made its way to the ocean. This was the prevailing view among scientists until 1957, when Roger Revelle discovered that the oceans could not absorb excess CO2 at the rate previously believed. You can read more about Revelle's discovery here.
Revelle's ideas caused scientists to start taking another look at the possible long-term effects of increasing atmospheric CO2 levels. One of the first things that scientists noticed was that Revelle had made an error. He assumed that the amount of CO2 being added to the atmosphere would continue at the same rate. In fact, the rate at which CO2 was being added to the atmosphere was increasing rapidly. This is because many countries, including some with huge populations like China and India, were rapidly industrializing. This rapid industrialization required huge amounts of electricity to run manufacturing industries and also to meet increasing consumer demands for reliable electricity, refrigerators, televisions, and other electrical devices. Scientists understood that if Revelle was right about the ocean's inability to absorb excess CO2, the rising CO2 levels would accelerate the greenhouse effect.
Humans use many different types of fossil fuels. But, they are not all equal when it comes to CO2 emissions. Some types of fossil fuels produce nearly twice the amount of CO2 as others Energy output is commonly measured in British thermal units (Btu). The chart below shows the number of pounds of CO2 emitted for each million Btus.
You can see from the chart that switching from coal to natural gas would result in a huge reduction in CO2 emissions. Converting our energy production to solar or wind would result in even greater reductions. Keep in mind that neither solar nor wind means zero CO2 emissions. Even though there are no solar emissions from a solar panel or a wind turbine, they both need to be manufactured. Manufacturing requires energy, and given the current state of our energy production, manufacturing solar panels or wind turbines results in adding CO2 to the atmosphere.
What Causes Global Warming?
Although anthropogenic climate change is driving global warming, there are also natural processes that can act to change Earth's temperature. Solar radiation, or the amount of energy coming from the sun, is not constant. It changes over time. Scientists believe that the "Little Ice Age" was caused by a decline in solar activity. The Little Ice Age was a period of unusually cold temperatures that lasted from about 1650 to 1850. Volcanoes, too, can play a part in changing Earth's temperature. Volcanoes emit both particles and gases when they erupt. The ash that is spewed from an erupting volcano will cool the Earth, because the ash reflects sunlight away from the planet. The CO2 emitted by an erupting volcano will eventually cause the planet to get warmer because of the greenhouse effect.
Scientists were able to observe a reduction in global temperature for a year or two after the massive eruption of Mount Pinatubo in 1991. You can't use a single eruption as proof that volcanoes make the planet cooler, but scientists have observed the same reduction in global temperature when examining multiple eruptions.
The U.S. Geological Survey has estimated that volcanoes emit about 100 million to 300 million tonnes (a tonne is equal to 1,000 kilograms, or about 2,200 pounds) of CO2 per year. That's equal to about 1% of the amount of CO2 that humans release each year just from burning fossil fuels.
Regardless of whether greenhouse gases are produced by humans or from natural sources, these gases are what cause the greenhouse effect. And, the greenhouse effect is what causes the planet to get hotter.
Earth's climate results from a balance between the amount of energy coming from the sun and the amount of that energy that is radiated back into space. The radiation from the sun consists of visible light, infrared (heat), and ultraviolet radiation. Some of the radiation produced by the sun is absorbed by the atmosphere, the oceans, and the surface of the Earth. Some of it is reflected back into space. For the temperature on Earth to remain stable, the amount of solar radiation coming into the atmosphere should be about the same as the amount leaving the atmosphere.
Changes in the atmosphere cause changes in this balance. As the amount of CO2, methane, nitrous oxide, and other greenhouse gases in the atmosphere increase, the atmosphere acts increasingly like a blanket around the Earth. The infrared radiation that strikes the Earth is not radiated back into space, because it cannot pass through the blanket of greenhouse gases. This causes the heat to be trapped. This illustration shows how that works.
Anthropogenic Climate Change
We know that the climate is changing right now. The Earth is getting warmer. We see that air temperatures are rising and ocean temperatures are rising. We see that ocean levels are rising because ice sheets and glaciers are melting. We see that increased ocean temperatures are leading to more frequent and more powerful storms. We see rising atmospheric CO2 levels. We see that the ocean is growing more acidic due in part to these rising CO2 levels. We see that some organisms are no longer able to live in their chosen environment because of rising temperatures, while others have been able to expand their reach into environments that were once too cold. The question is not whether the Earth is getting warmer. The question is why?
Scientists have concluded that climate change is being driven by humans. This is called anthropogenic climate change. "Anthropogenic" means "caused by man." Does every scientist agree? No, but it's hard to find anything that 100% of scientists agree on. But, the overwhelming majority of scientists believe that climate change is happening and that it is happening because of things that humans are doing. What does "overwhelming majority" mean? Well, the commonly stated number is 97%. There are some who disagree with this number, and say that it is closer to 90%, or even 85%. Honestly, does it matter? If you had a wart growing on the tip of your nose and you went to 100 doctors, would it really matter if 85 or 90 or 97 of them gave you the same advice? Remove that wart before it eats your head!
There are, of course, people who disbelieve the scientists. They are called "climate deniers" and we'll discuss them later. For now, let's just have a look at the evidence that scientists have relied on to reach the conclusion that the climate change being observed is anthropogenic. The evidence consists of:
- Global air temperature rise.
- Warming oceans.
- Shrinking ice sheets.
- Glacial retreat.
- Decreased snow cover.
- Sea level rise.
- Declining sea ice.
- Extreme weather events.
- Ocean acidification.
Let's examine each of these.
Global Air Temperature Rise
Today, we measure the air temperature in many places. There are thousands and thousands of temperature measurement stations all over the world. But that has not always been the case. The longest continuously-running measurement of temperature started in England in 1659. Ever since, there has been a continuous measurement of temperature at the same location. But that is just a single location. The longest running global measurements began in 1850. When you look at charts of temperature, you'll notice that many of them begin in 1850.
We know that the average surface air temperature on Earth has increased by about 2 degrees Fahrenheit since the late 1800s. We also know that the bulk of that warming has occurred just in the past 35 years.
If you look at the measured temperature record, you'll see that 16 of the warmest years on record (remember, that goes back to 1850) have occurred since 2001. In fact, 2016 was the warmest year on record. And, 8 of the 12 months in 2016 were the hottest on record for those months.
Here are some graphics that show the change in global surface temperature. In these photos, blue means much colder, light blue means colder, white means no change, yellow means hotter, and red means much hotter.
1950
1980
1998
2016
Warming Oceans
Heat will move from one object to another. When you put a pot of water on the stove, the heat from the flame makes the pot hot, and the heat from the pot makes the water hot. The same thing happens to the water in the oceans. If the temperature of the air is warm, the heat from the air will be transferred to the ocean, making the ocean warmer. Not all substances absorb heat at the same rate, nor do they release heat at the same rate. Let's go back to the example of the pot of water. When you first put the pot of water on the stove, it's perfectly safe to put your hand in the water. It's still cool. If you were to push your hand further into the pot, though, you would burn your hand when you touched the bottom of the pot. Metal absorbs heat much faster than water. If, after the water boiled, you poured into another container and waited a few minutes, you'd discover that the pot wasn't too hot to touch anymore. The metal in the pot transfers its heat to the air quickly. The water, though, would still be hot enough to burn your hand. Water takes longer to get hot, but it retains heat. This is one of the reasons that temperatures near the coast rarely get very hot or very cold. The ocean absorbs heat from the air, keeping the air from getting too hot. It also releases heat into the air, preventing the air from getting too cold. Remember that. It will be important later.
We have observed that much of the increased heat on Earth has been absorbed by the oceans. Since 1969, the top 700 meters of the oceans has gotten about .3 degrees Fahrenheit warmer. That might not seems like a big change, but consider the difference between 32.1 degrees Fahrenheit and 31.9 degrees Fahrenheit. It is the difference between ice and water! So even small changes in the temperature of the ocean can mean huge differences where the ice sheets meet the ocean. Have a look at this chart that shows the change in the temperature of the oceans at the surface since 1880.
Shrinking Ice Sheets
If you think that warmer air and warmer oceans might have an effect on ice sheets, you'd be right! The ice sheets are melting, and in doing so they are causing sea levels to rise. In the Northern Hemisphere, Greenland lost between 36 and 60 cubic miles of ice each year between 2002 and 2006. In the Southern Hemisphere, during the same time period, Antarctica lost 36 cubic miles of ice. In the past 20 years, two ice shelves in Antarctica have already collapsed into the ocean. A third shelf is in danger of similar collapse. When ice shelves collapse into the ocean, the allow glaciers to flow more quickly into the ocean. Which leads us to...
Glacial Retreat
Glaciers are retreating almost everywhere in the world. Glaciers in the Alps (Europe), the Himalayas (Asia), the Andes (South America), and the Rockies (North America) are melting. The same thing is happening in Alaska and Africa. This chart illustrates what is going on:
The photograph below shows the difference in Alaska's Muir Glacier using photographs taken in 1941 and again in 2004. The difference is striking.
Glacier National Park, in Montana, is one of the places in the continental United States where glaciers still exist. In the mid 1850s, there were about 150 glaciers in the park. By 2010, only 25 remained. Chances are good that by the time you are ready to take your children to Glacier National Park, the glacier will be gone. Scientists have estimated that the glaciers will disappear by 2030 if current climate patterns continue. We seem to be okay with that. Can you imagine the uproar if tomorrow the government announced that we would be converting the Grand Canyon to a landfill?
The photos below show the Grinnell Glacier in Glacier National Park in 1911 and again in 2008. Plan your visit soon!
Decreased Snow Cover
Another piece of evidence that scientists relied on in concluding that Earth is growing warmer is snow cover.
It's important to understand the difference between the amount of snow that might fall during Winter and snow cover. Snow cover measures how much of the ground is covered by snow. Snow cover is important for two reasons. First, because snow is white, it reflects light (and heat) from the sun back into the atmosphere. Snow cover reflects about 80% to 90% of the sun's energy back into the atmosphere, helping to cool the planet. Second, snow helps to keep the ground warm. At first thought, this might seem ridiculous. How can something as cold as snow keep anything warm? Well, snow acts like a blanket. Yes, it is cold, but it is often not as cold as the air temperature around it. Perhaps you've heard that if you find yourself stranded in a blizzard you should build a snow cave. That's because the snow cave will help to keep you warm. So snow cover helps to prevent ground moisture from evaporating and protects soil and the organisms that live in soil from changes in the air temperature above.
Climate change might actually cause more snowstorms because of increased evaporation. But the number and intensity of snowstorms is not as important to the overall climate as snow cover is. And, because temperatures are increasing, the snow that falls is not lasting as long before it melts. So, higher temperatures result in less snow cover, and less snow cover results in higher temperatures.
Rising Sea Levels
In the last century, the level of the ocean rose by 8 inches. And, the rate at which sea levels rose in the past 20 years is double the rate of the last century. Now, 8 inches might not seem that significant. But, the effects of even this modest rise in sea level is already being seen. In parts of the U.S., the higher sea levels are allowing sea water to get into aquifers and other sources of fresh water. Residents of the Carteret Islands, an atoll in the Pacific Ocean, have left their homes and relocated because of rising sea levels. And, they are just the first in what is expected to be a flood of climate change refugees. The chart below shows the increase in sea level since 1880.
Remember reading about shrinking ice sheets a few paragraphs ago? Well, not only are they shrinking, but they are becoming unstable. The ocean is getting under the ice at the coastline of Greenland, causing the ice to become unstable and break off. When the ice breaks off into the ocean, it melts fairly quickly. Sometimes, a portion of the ice shelf melts into a lake that is held out of the ocean by an ice dam. If the ice dam fails, then all that fresh water is released into the ocean at the same time. A major collapse of the Greenland ice shelf would cause a quick and catastrophic increase in sea levels.
How many people might be affected by an increase in sea levels? A lot! These two charts will give you an idea.
Please notice that the first chart shows estimates based on two different increases in temperature -- 2 degrees C and 4 degrees C. The Paris Agreement (more about that later) sets a target of 2 degrees C. But, independent analysis suggests that even if the countries who have signed the Paris Agreement meet their CO2 emission limits, Earth's temperature will rise by 3 degrees C. And, many countries are neither meeting their reduction targets or even taking the actions they promised to take to meet those targets. Unless something changes, the actual increase in temperature will be much closer to 4 degrees than 2 degrees, putting a huge number of people at risk.
Declining Sea Ice
It's not just melting ice sheets that we need to worry about. The amount of sea ice in the Arctic is also declining. The area of the ocean covered by sea ice has declined rapidly. In addition, the thickness of the remaining ice has also declined. The graphic below shows the change in Arctic sea ice between 1984 and 2012.
Keep in mind that ice works a lot like snow cover. That is, it reflects much of the energy of the sun back into the atmosphere, helping to keep the planet cool. As the amount of ice declines, less energy is reflected, allowing temperatures to rise.
Extreme Events
One of the most visible effects of climate change is the increase in the number and severity of extreme weather events. The number of record high temperature events in the U.S. has been increasing since 1950. You don't need to go far from home to see examples. Just this week in Los Angeles, we broke records for high temperature (this was written on November 25, 2017.) The number of record low temperature events in the U.S. has been declining since 1950. The number of intense rainfall events in the U.S. has been increasing. You can see a chart of extreme 1 day rain events in the U.S. below.
Storms and hurricanes are one of the most destructive examples of extreme weather events. Of the 15 years with the most named storms since 1851, 10 of them have occurred since 2000. Of the 10 seasons with the most hurricanes since 1851, 7 have occurred since 1950, 5 have occurred since 1995, and 3 have occurred since 2005. Global warming is causing larger and more intense storms and hurricanes because they get their energy from warm water. As the ocean absorbs more and more heat from the atmosphere, we can expect hurricane activity and intensity to increase.
Ocean Acidification
Since the beginning of the Industrial Revolution, the acidity of ocean surface waters has increased by 30%. This is because the ocean absorbs some of the CO2 in the atmosphere. The amount of CO2 absorbed by the ocean is increasing by about 2 billion tons per year. The chart below illustrates this.
You can see from the chart that as the amount of dissolved CO2 increases (the charts on the left,) the pH level drops. Lower pH levels indicate increased acidity. Some of the effects of increased ocean acidity are already being observed. Coral reefs, which are home to a huge number of plant and animal species, are being bleached and are dying. Increased acidity can also kill phytoplankton. Besides being food for a large number of ocean species, phytoplankton and other marine plants are responsible for producing about 70% of the oxygen in Earth's atmosphere.
How Is the World Responding to Climate Change?
As the evidence for anthropogenic climate change has piled up, more and more nations realized that they needed to take action. Unfortunately, global problems require global solutions, and getting countries with very different political systems, very different populations, very different perspectives, and very different economies to agree is a huge challenge. But, it has been accomplished before.
In 1973, scientists discovered that the ozone layer that protect the Earth (and everything on it) from ultraviolet radiation from the sun was being destroyed by a class of chemicals known as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). By 1985, the 20 largest producers of these ozone-destroying compounds signed a treaty and agreed to phase out the production and use of the compounds. By 2015, 197 countries had signed. This was the very first time in United Nations history that a treaty was universally ratified.
A similar approach was taken in response to climate change. In 2015, after much negotiation, the Paris Agreement as adopted. It has been signed by 195 countries, but the United States has said it will pull out of the agreement. Although the Paris Agreement is a good first step, it does not go far enough, because it does not actually force any of the signatories (countries who signed the agreement) to take specific actions. Each country is responsible for coming up with its own plan to reduce emissions, and there is no requirement that each country follow the same rules. The goal of the Paris Agreement is to reduce greenhouse gases enough to keep the global temperature rise this century below 2 degrees Celsius above pre-industrial levels.
BREAKING NEWS: The Powerpoint I used in class said that every country except Syria and the United States is party to the Paris Agreement. In November, 2017, Syria said it would sign the Agreement, leaving the United States as the only country that is not part of the worldwide effort to reduce greenhouse gas emissions.
The ozone layer issue is not only illustrative of how the nations of the world can reach agreement on an issue of importance, but also how those who stand to lose will fight back. Shortly after the research implicating CFCs and HCFCs in the destruction of the ozone layer, industry began to fight back. Robert Abplanalp, the inventor of the aerosol valve that you find on the top of your cans of Axe, complained to the Chancellor of the University of California at Irvine for allowing scientists to speak out against ozone-depleting compounds. Remember that CFCs and HCFCs were very important to the aerosol can industry, because they used it to push ingredients out of the can through the aerosol valve. The chairman of the board of DuPont (a company that mass-produced and sold CFCs and HCFCs) said that the ozone depletion theory was "a science fiction tale... a load of rubbish... utter nonsense." In 1986, after the ozone treaty was created and signed, DuPont was still claiming that "we believe there is no imminent crisis that demands... regulation." Even as late as 1988, DuPont was still fighting. In a letter to the U.S. Senate, their chairman of the board wrote, "At the moment, scientific evidence does not point to the need for dramatic CFC emission reductions. There is no available measure of the contribution of CFCs to any observed ozone change." The denial of a problem by industries likely to lose money as the result of regulation is nothing new. The tobacco industry fought regulation for years. They claimed that there was no link between smoking and lung disease. They did this even though their own scientists knew that smoking did, in fact, cause lung disease. They claimed that nicotine was not addictive, when their own scientists knew it was. They claimed that they were not advertising to children, even though some cigarette companies used cartoon characters in their ads and advertised on television shows aimed at children. And today, we are seeing companies that will lose money if limits on CO2 emissions fighting against regulations and using their allies in Congress to do the same.
A Short Detour - Ice Core Samples
So if global temperature measurements did not begin until 1850, how do scientists know what the temperature was at the time of the dinosaurs, or even before that? Remember isotopes? You know, unstable versions of an element that contain extra neutrons? Well, there is an isotope of oxygen that is temperature-dependent. Some atoms of this isotope get trapped in ice. Scientists can use ice cores to go back in time. Years in ice cores are identified much like rings in a tree. So, scientists who examine ice cores know how long ago a particular "ring" was formed, and by measuring the amount of Oxygen-18, they know what the temperature was. There are actually several ways that scientists determine what the temperature was before we started measuring it, but ice cores are one example.
Ice cores are also how scientists know what the concentration of CO2 in the atmosphere was before we had ways to measure it. Just like atoms of oxygen become trapped in ice, so do tiny bubbles of air. Scientists can look at the air trapped in those bubbles to find out what the atmosphere consisted of millions of years ago.
So what do we know? We know that the average temperature of the Earth has been hotter than it is now, and it has been colder than it is now. We know that there have been times in the past when there was more CO2 in the atmosphere and times when there was less. We know that when there was more CO2 in the atmosphere, the Earth was hot and when there was less CO2 in the atmosphere the Earth was cold.
Climate Denial
Just because the overwhelming majority of scientists endorse the idea of anthropogenic climate change does not mean that the overwhelming majority of ordinary people do.
Yale University conducted a study in 2016 to see what Americans believe about climate change. They've published their data in a really cool map format. They use color coding to show what areas of the country believe or disbelieve different aspects of climate change. For example, pretty much all over the country at least half of Americans surveyed believe that global warming is happening. And, pretty much all over the country at least half of Americans surveyed trust climate scientists about global warming. But, in most of the country, less than half of the Americans surveyed believe that most scientists think global warming is happening. And, perhaps scariest of all, there are huge sections of the country where less than half of the American surveyed believe that global warming is caused mostly by human activities. What can possibly explain this?
Actually, the map provides some of the answers. Unless you've been unconscious for the past year and a half, then you know all about red states and blue states. Red states are those that voted for President Trump and blue states are those that voted for Hillary Clinton. But, you can break that down further into Congressional Districts. You should know that each state is represented in Congress by 2 senators. Every state gets the same number of Senators, regardless of population. A state like California, with nearly 40 million people, gets the same number of senators as Wyoming, which has a population of about 600,000. The House of Representatives works differently. In theory, the number of Congressmen is based on population. California has 53 representatives in Congress, or about 1 for every 705,000 people. Wyoming gets just 1. So, the House of Representatives comes closer to equal representation.
The country is broken up into Congressional Districts. California is broken into 53 Congressional Districts. Texas is broken into 36 Congressional Districts. Since Wyoming has only one member of Congress, it's its own Congressional District. What important is that when a person runs for Congress, the only people who get to vote are the people who live in that Congressional District. So instead of looking at red states and blue states, we can look at red districts and blue districts. You can do that with the Yale map. And what you'll find is that most of the people who believe in anthropogenic climate change live in blue districts, and most of the people who disbelieve live in red districts. It should come as no surprise, then, that politicians running in red Congressional Districts tend to deny anthropogenic climate change, and those running in blue Congressional Districts argue that we need to take action. So not only do we have large numbers of ordinary Americans disbelieving the scientists, we also have large numbers of politicians publicly denying that humans have anything to do with climate change.
There is another interesting factoid illustrated by the map. There is not a single Congressional District where a majority if people say they discuss global warming "at least occasionally." Not one. That is a problem. Because until people begin discussing the issue, nothing is going to change. The map is actually a lot of fun to play with. You will need to know some of the information contained on the map to answer questions on the test. You can find the map here.
Who Are the Climate Deniers?
Although climate denial is a worldwide phenomenon, it is most prevalent in the United States. So who are these people?
After Roger Revelle's groundbreaking research in 1957, more and more people were waking up to the danger of anthropogenic climate change. When President Reagan cut spending on environmental research in 1981, Senator Al Gore of Tennessee convinced Congress to open hearings on the subject. That turned the climate change debate into a political debate between Democrats and Republicans. When the U.S. Environmental Protection Agency issued a report in 1983 that said global warming was a threat with potentially catastrophic consequences, President Reagan called it "alarmist." But a few years later, when must of the U.S. was experiencing summer droughts and head waves, public attention was again focused on climate change, and Congress started talking about new environmental regulations. That got the attention of the fossil fuel industry.
Industry funded organizations, led by the Global Climate Coalition and the George C. Marshall Institute started working to spread doubt about global warming. They used the same strategy that had been used before by the tobacco industry to try to get people to ignore the fact that cigarettes caused cancer and other serious lung diseases. These organizations recruited a small group of scientists, including some who had worked for the tobacco companies. These scientists, and the organizations they worked for, began making personal attacks on the reputation of scientists who they disagreed with and promoted the idea that there was a global warming conspiracy.
Today, the fight against the scientific consensus is continuing, led by organizations such as The Heartland Institute, the American Petroleum Institute, the Western Fuels Association, and the Republican Party.
The Politics of Climate Change
You can see from the Yale map of public opinion on climate change that blue Congressional Districts generally accept the scientific consensus on anthropogenic climate change and red states generally reject that consensus. That has led the two major political parties to adopt opposite positions on climate change and energy issues. My reason for including this information is not to support one political party over another. It is simply to show that politicians, if they want to be elected, need to show agreement with their constituents. Below is a comparison between the Republican and Democratic official platforms as adopted by their respective conventions in 2016.
Politicians also rely on their contributors in order to have enough money to run for office and, if they win, to get reelected. What do the top 7 oil and gas company political contributors to political parties look like so far in 2017? Check out the chart:
Again, the purpose of providing this information is not take sides. The purpose is to show that the issue of climate change has been turned from a scientific one to a political one. Republican candidates, and the Republican party, say what they say because it is what their constituents and their donors expect them to say. There are other issues where one could make the argument that the facts are with the Republicans and it is the Democrats who are catering to their contributors. This section of the Online Textbook is about anthropogenic climate change, and these data are presented to support the scientific consensus and protect it from attacks by climate deniers.
What do Deniers Claim?
Claim: CO2 is only a trace gas in the atmosphere and has little effect on the climate.
Scientific consensus: The scientific consensus is that human activity is the leading cause of climate change. Burning fossil fuels adds about 30 billion tons of CO2 to the atmosphere each year. This is about 130 times and amount produced naturally by volcanoes.
Claim: Water vapor is a more significant greenhouse gas and it is left out of many climate models.
Scientific consensus: The effect of water vapor has been included in models of climate change since climatology began in the 1800s. Although water vapor is, in fact, a greenhouse gas, CO2 is the primary driving force behind increasing temperatures.
Claim: Global warming stopped recently.
Scientific consensus: There are always short term fluctuations in climate and temperature. However, the long term pattern clearly demonstrates that the Earth is getting hotter.
Claim: Sunspots and cosmic rays explain the warming trend.
Scientific consensus: These factors are already built into climate models, and they cannot explain the warming trend that has been observed.
Claim: Global warming is a conspiracy. Scientists are just trying to scare people for their own financial interest.
Rebuttal: Where is the evidence? The scientific consensus for anthropogenic climate change consists of scientists from a wide range of social, political, organizational, and national backgrounds.
Why do People Believe the Deniers?
The Yale map shows that even though most people say they trust scientists, they don't think that most scientists believe that humans are responsible for climate change. The Yale map shows that a huge segment of the American population does not believe that humans are responsible for climate change. How did this happen? The answer is complicated, and no one can really say for sure, but there are some compelling possible answers.
They Give Straight Answers
Most people like straight answers. Scientists don't believe in straight answers, because they know that they can rarely be 100% sure that they are right. Scientists also talk like scientists. That is, they use scientific vocabulary to explain very difficult and complicated subjects. The average person (and that includes the average science teacher) cannot really understand subjects the way that most scientists explain them. Climate deniers, on the other hand, tell their story simply, with simple language, and with 100% certainty. Compare these two statements:
"Water vapor feedback, as derived from current models, approximately doubles the warming from what it would be for fixed water vapor. Since the SAR, major improvements have occurred in the treatment of water vapor in models, although detrainment of moisture from clouds remains quite uncertain and discrepancies exist between model water vapor distributions and those observed."
"Wow, it's snowing in Israel and on the pyramids in Egypt. Are we still wasting billions on the global warming con?"
The first statement came directly from a scientific paper explaining the basis for anthropogenic climate change. Assuming you were still awake at the end of the statement, could you understand it? Is there anything in that statement that incites you to take action?
The second statement came directly from a politician. Is the statement short and to the point? Do you need a PhD in climatology to understand it? Does it help you to stop worrying about a problem that you don't understand when you are given an excuse to quit worrying?
They Use Mass Media
You might wonder how the voices of climate deniers can be so loud and so numerous if most scientists really believe that humans cause climate change. Part of the answer comes from the way that most people get their news. Scientists don't publish their work in the popular media. Scientists publish their work in peer-reviewed journals. But climate deniers and the scientists they have recruited to their cause do not rely on peer-reviewed journals. There is very little chance that their work would pass the scientific requirements to be published in a journal. So, they publish their work in the type of media that ordinary people access. Popular magazines. Good Morning, America. YouTube. So even though the number of scientists who are climate deniers is tiny, they have a much louder voice. No wonder people think that the science is "not settled."
They Rely on Ignorance
Deniers also rely on the fact that most people have not been adequately educated about anthropogenic climate change. Basically, they are able to tell straight out lies and not get caught by the average person. Think about your relationship with me, or with any of your teachers. When you come to class, do you assume that what you are going to learn is factual? It just so happens that I do tell you the truth, but could I lie about some scientific concept and get away with it? Unless you already knew a particular scientific fact, or were motivated enough to check up on me, of course I could! Climate deniers rely on that. They are able to make up facts because they know that the average person hasn't already learned the facts and is not likely to check up on them. They also rely on the fact that when people do check, they start with Google. It is not that difficult to "game" the system so that your website, whether true or false, comes up at or near the top of a Google search. Climate deniers are very well funded by their industry supporters, so they are able to purchase huge amounts of advertising on social media.
What Can You Do?
Many people, when convinced that anthropogenic climate change is real, throw their hands up in frustration. They just don't see how an individual can make any difference at all. I don't buy that attitude. It's that sort of attitude that got us into this mess in the first place.
Take Small Steps
First, you need to take responsibility for your actions. That means that you need to reduce your own carbon footprint as much as you can. Rely less on automobiles and more on public transportation, bikes, or your feet. You need to be conscious of your use of energy. Unplug all those chargers you have around your house that have nothing plugged into them. Even when they are just sitting idle, they are using electricity. If unplugging them and plugging them back in is too much trouble for you, then get a switched outlet extension, plug them into the extension, and turn it off when you're not using it. Don't leave the lights on in a room because "I'm coming back in a few minutes." If you are still using incandescent bulbs in your house, convince your parents to replace them with LED bulbs. Don't fall asleep with the TV on. Most TVs have a sleep timer function; use it. Keep the temperature in your house a little less extreme. Don't try to use your heater to make toast in the winter and your air conditioner to make slushies in the summer.
Educate Others
Talk to your friends and relatives about climate change and the need to take action. At this point, you may be the expert in your family when it comes to the scientific basis for anthropogenic climate change. Use your knowledge to educate others.
Think Critically and Verify
You simply cannot allow yourself to believe everything that sounds right. Just because someone says they are an expert does not mean that they are. And, even if they are an expert, they might still be wrong. Think critically. Does what you are hearing, reading, or seeing really make sense? Do you suspect that someone might just be trying to take advantage of your age or ignorance to convince you of something that isn't true? It's perfectly okay to think that a YouTube video that "proves" the moon landing was faked is cool, so long as you don't get fooled into believing that it's true. The truth is out there if you're willing to take the time to find it.
Become Politically Aware
Most kids share their political views with their parents. That's natural and perfectly okay. After all, most of us share the morals and values of our parents, so it's not surprising that we share their political beliefs as well. It really doesn't matter if you are Republican or Democrat or Libertarian or Peace and Freedom or any other political party. Being a member of a political party means that you get to set the agenda. If there is a candidate who stands for what you believe, that's great. If there are things that you disagree with the candidate on, why not try to win them over to your point of view? You might think that you're too young for a candidate to care. Not true! First, many kids have a huge presence on social media, so what they say counts. Second, most of you are only 5 years away from being able to vote, and many if not most of the politicians currently in office will be looking for your vote when you turn 18. You've never too young to tell them what it will take to earn your vote.
Open the Discussion
Remember the Yale map? The most disturbing thing I noticed is how small a percentage of the population discusses climate change. How can we ever expect people to take action to solve a problem if they aren't even talking about it? Most people only discuss issues when they find a group of people they agree with. I'm suggesting that you do the opposite. Open a discussion about anthropogenic climate change with someone who doesn't believe it, or who isn't sure. Instead of telling them that they are wrong, and that you are right, listen to what they have to say. Find some common ground. Then build on it. You might be surprised to see them slowly come around to your side.
Study Links
Human Impact - Part Two Slideshow
Student-Produced Google Slides presentations
Climate Change:Temperature (1)
Climate Change:Temperature (2)
Solid Waste - None of the student produced presentations are comprehensive or accurate enough to be used as part of the Online Textbook