"It's perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential population growth. Jobs and wages depend on science and technology."
“Scientists are more confident than ever that humans are causing global warming. 97% of scientists have concluded that humans are to blame for global warming."
Source: Ilissa Ocko, (Ph.D. from Princeton University in Atmospheric
and Oceanic Sciences, Climate Scientist).
Climate is usually defined as the "average weather" in a place. It includes patterns of temperature, precipitation (rain or snow), humidity, wind and seasons. Climate patterns play a fundamental role in shaping natural ecosystems and the human economies and cultures that depend on them.
To determine if any climate change is occurring, climatologists look for general rises or falls over a 30-or-more year period in measurements such as temperature and precipitation. This is because weather in any area often fluctuates widely from day to day and year to year. One very hot year does not prove the planet is getting warming, and one very cold year does not prove it is not.
Climate change is neither new nor unusual. Over the past 3.5 billion years, Earth’s climate has been affected by many factors such as volcanic eruptions, continents moving slowly over tectonic plates, changes in solar input, impacts with large meteors, and our slightly wobbly orbit around the sun. In the last 900,000 years, prolonged periods of considerable atmospheric warming and cooling have occurred. During the last 10,000 years, we have lived with a fairly stable climate based on a fairly stable average surface temperature. Most of the recent overall rapid rise in global average temperature has taken place since 1978.
Based on a review of several methodologically sound scientific studies, the American Association for the Advancement of Science has concluded that rising inputs of greenhouse gases from human activities are now overwhelming the combined effects of natural factors. Past temperature changes and climate change that took thousands or even hundreds of thousands of years to occur are now occurring within just several decades.
Scientific Evidence of Change
What are the types of scientific evidence that document significant change in climate? Scientists specify nine types of evidence that lead to the conclusion that our climate is undergoing its most rapid change and that human activity is the largest instigator of it (Environmental Defense Fund, 2017a). They are:
1. Basic chemistry: Chemical understanding that carbon dioxide is emitted when we burn carbon-based materials (research beginning in 1900s).
2. Mathematical accounting: Basic accounting of what we burn and how much carbon dioxide we emit (data collection beginning in 1970s).
3. Chemical measurement: Measurement of the amount of carbon dioxide in the atmosphere and trapped in ice that shows higher levels than anything seen in at least hundreds of thousands of years (measurements beginning in 1950s).
4. Chemical analysis: Atmospheric carbon dioxide reveals the increase is coming from burning fossil fuels (research beginning in 1950s).
5. Basic physics: Understanding that carbon dioxide absorbs heat (research beginning in 1820s).
6. Monitoring of climate conditions: This monitoring shows that recent warming of the Earth is correlated to and follows rising carbon dioxide emissions (research beginning in 1930s).
7. Ruling out natural factors: Other factors that could cause climate change like the sun and ocean cycles have been ruled out (research beginning in 1830s).
8. Employing computer models: Computer models of natural versus human-influenced simulations of Earth point to human-influenced causes (research beginning in 1960s).
9. Consensus among scientists: 97 percent of the world’s climate scientists concur that climate change is happening now and is caused mostly by human activities (polling beginning in 1990s).
Scientific Evidence of the Role of Human Activity
In pinpointing the role of human activity in climate change, it is necessary to understand isotopes. We can explain them in a series of eight statements (Miller and Spoolman, 2016):
1. The basic building block of matter is the atom – the smallest unit of matter into which an element can be divided and still have its distinctive chemical properties. Atoms are minute – more than 3 million hydrogen atoms could sit side-by-side on the period at the end of this sentence.
2. Each atom contains a certain number of subatomic particles – neutrons (no electrical charge), protons (each with a positive electrical charge), and electrons (each with a negative electrical charge).
3. Each atom has an extremely small center called the nucleus – it contains one or more protons and usually one or more neutrons. Outside the nucleus are the electrons which are in rapid motion. Almost all of the atom’s mass is concentrated in the nucleus.
4. Each element has a unique atomic number which is equal to the number of protons in the nucleus of its atom. For example, carbon has 6 protons in its nucleus and its atomic number is 6.
5. The mass of an atom is described by its mass number, the total number of neutrons and protons in its nucleus. For example, a carbon atom with 6 protons and 6 neutrons in its nucleus has a mass number of 12.
6. Each atom of a particular element has the same number of protons in its nucleus, but the number of neutrons can vary so that its mass number can vary.
7. Isotopes are forms of an element having the same atomic number but different mass numbers. For example, carbon-12 has six protons and six neutrons, carbon-13 has six protons and seven neutrons, and carbon-14 has six protons and eight neutrons.
Carbon atoms are constantly cycling through living and nonliving matter. These carbon atoms can be studied in relation to each other (calculating a carbon ratio) which is important because they function differently. As one example, during photosynthesis, plants absorb more carbon-12 atoms than carbon-13 atoms because the carbon-13 atoms are slightly heavier.
This is the connection to human activity. When fossil fuels (coal, oil, gas) are burned, they release a disproportionate amount of carbon-12 into the atmosphere, and the ratio of carbon-13 to carbon-12 is reduced. When comparing today with 2,000 years ago (based on studies of trapped bubbles of atmospheric gas in ice cores in Greenland and Antarctica), it is determined that the amount of carbon dioxide has increased since then but that the ratio of carbon-13 to carbon-12 has gotten much lower.
Moreover, this new pattern began around 1850 – just when humans began burning fossil fuels. Unfortunately, the shift has been very dramatic. Before humans began burning fossil fuels, carbon ratios could vary by as much as 0.03 percent over a couple thousand years. In the last 150 years (since fossil fuel burning began), the ratio has shifted by 0.15 percent – five times more than has historically occurred in a time period 12 or 13 times shorter. Our climate is rapidly changing, it is largely due to the presence of increasing greenhouse gases, and change is progressing much faster than any seen in the last 2,000 years (Spooner, 2012).
The Consequences of Climate Change and Global Warming
What are the likely consequences of global warming (Miller and Spoolman, 2016):
1. More ice and snow are likely to melt. Most computer models project that climate change will be most severe in the world’s polar regions. This is important for several reasons including that the light-colored ice and snow help to cool the entire planet by reflecting incoming solar energy back into space. The melting of this snow and ice exposes much darker land and sea areas, which absorb more solar energy. This has led to warmth increasing most rapidly at the poles. This warming will accelerate the rapid melting of even more snow and ice in an escalating spiral of change.
Warmer temperatures are already reducing the amount of ice at the North and South Poles and throughout the Arctic and Antarctic regions. This melting ice adds fresh water to the oceans, raising the sea level relative to land. Even a slight increase in sea level can lead to some lands becoming submerged and to saltwater intrusion to freshwater rivers and wells (Spooner, 2012).
2. Permafrost is likely to melt. Permafrost is found in soils beneath about 25 per cent of the exposed land in Alaska, Canada, and Siberia. Huge amounts of carbon are locked up in permafrost soils. Human-caused climate change is expected to thaw out significant amounts of permafrost (as is already occurring in parts of Alaska and Siberia). This will lead to the rotting of a vast amount of organic material and release huge amounts of methane and carbon dioxide into the atmosphere. That too would create a mutually reinforcing cycle as those greenhouse gases will accelerate atmospheric warming.
3. Ocean levels will rise. The two major causes of global sea level rise are thermal expansion caused by warming of the ocean (since water expands as it warms) and increased melting of land-based ice, such as glaciers and ice sheets. The oceans are absorbing more than 90 percent of the increased atmospheric heat associated with emissions from human activity (National Ocean Service, 2017).
During the 1900s, the world’s average sea level rose by 7.6 inches – much from the increasing runoff from melting land-based ice. Between 2015 and 2100, it is projected that there will be another increase of 16 to 24 inches. Half to two-thirds of this rise will likely come from the melting of Greenland’s ice. However, if the rate of melting increases, it is conceivable that sea levels could rise by 3 to 7 feet by 2100. Just a three-foot rise would submerge several low-lying countries (such as Bangladesh and Fiji), completely flood over some of the world’s largest coastal cities (such as Venice, London, and New Orleans), and create massive flooding and erosion of barrier islands and coastlines in Florida, Texas, Louisiana, New Jersey, South Carolina, and North Carolina. Say good-bye to Brunswick County. Coastal fisheries would be damaged, and freshwater aquifers that provide drinking water would be contaminated with salt water.
In the United States, almost 40 percent of the population lives in relatively high-population-density coastal areas, where sea level plays a role in flooding, shoreline erosion, and hazards from storms. Globally, eight of the world's 10 largest cities are near a coast (National Ocean Service, 2017).
Read local expert, Dr. Richard Hilderman, on the danger of rising sea level:
4. Severe drought and other extreme weather will become more common. Warming increases the kinetic energy in the atmosphere. This will lead to longer, more frequent, and more intense heat waves which would lead to more heat-related deaths, reduce crop production, and expand deserts. Because a warmer atmosphere can hold more moisture, some areas such as the eastern coast of the United States will likely experience more flooding from heavy rainfalls. A World Meteorological Organization panel has forecast stronger hurricanes and typhoons. Forest fires will become more frequent and more intense. Several populations of insects that damage trees will flourish. Coastal wetlands (like in Brunswick County) are especially vulnerable. Should precipitation move further away from already dry areas, these regions may not be able to grow food or have adequate freshwater. The number of natural disasters has more than tripled since 1970 – 90 percent of them are weather related (Environmental Defense Fund, 2017c).
5. Biodiversity will be threatened. Biodiversity on every continent will be harmed. For example, the Amazon rain forest – one of the world’s major sources of biodiversity – could be lost and converted to tropical savanna. The biomes that organisms are best adapted to are likely to shift in location or disappear altogether. Many species will have to quickly adapt to avoid extinction. As the atmosphere warms, 25 to 50 per cent of the world’s species could face extinction by 2100.
Global warming is contributing to rising ocean temperatures. Combined with the effects of acid rain, the ocean is becoming a less hospitable environment for many organisms. For example, coral and shellfish are already suffering. Coral reefs are highly sensitive to small changes in ocean temperatures. The heat stresses the algae that nourish the corals and provide their vibrant colors. The algae then leave, and the corals eventually starve – an event known as bleaching. As coral reefs are home to many other species, such as fish, their collapse would disrupt the entire ecosystem. Also, a more acidic ocean affects the normal calcium balance, meaning creatures with calcified shells, such as shellfish and coral may not have enough calcium to grow (Environmental Defense Fund, 2017b).
6. Food production could decline. If the atmosphere keeps warming as projected, farmers will experience significant problems. Climate change models project a decline in agricultural productivity in currently warm climates (as they get hotter), although some currently colder areas might become more productive (as they get warmer). The flooding of farm lands could become an increasing problem.
7. Human health, national security, and world economies will be threatened. Prolonged heat waves will likely increase illnesses and death – especially among older people, people in poor health, and people who cannot afford air conditioning. A warmer, more carbon dioxide-intense atmosphere will be conducive to insects, including mosquitos and ticks, which transmit severe illnesses such as West Nile virus and Lyme disease. Warming will also favor microbes, toxic molds, fungi, pests, and weeds. Smog will increase leading to more heart and respiratory disease. Recent reports from the U.S. Department of Defense and the National Academy of Sciences warn that climate change could lead to geopolitical conflicts centered on water shortage, food scarcity, environmental degradation, and mass migration of environmental refugees. Also, climate change could lead to reduced economic productivity, disruption of supply chains, higher costs for food and other commodities, and higher levels of risk for companies and investors.
What Can Be Done?
The starting points for doing something about climate change and global warming are the same as with all of the environmental issues covered in this section of the website:
Become more knowledgeable about this issue.
Discuss this issue with others; learn from them and help them learn from you.
Incorporate practices into your life to reduce carbon dioxide emissions. Examples are:
o Calculate your carbon footprint (there are several helpful websites)
o Drive a fuel-efficient car, walk, bike, carpool, and use mass transit
o Reduce garbage by reducing consumption, recycling, and reusing more items
o Use energy-efficient appliances and compact fluorescent or LED light bulbs
o Wash clothes in warm or cold water and hang them to dry
o Close window curtains to keep heat in or cold out
o Use a low-flow showerhead
o Eat less meat or no meat
o Heavily insulate your house and seal all air leaks
o Use energy-efficient windows
o Set your hot water heater to 120o F
o Plant trees
o Buy from businesses working to reduce their emissions
Join forces with groups and organizations that are knowledgeable about environmental issues in general (BEAT!) and about this issue in particular. Organizations have greater access to scientific expertise, have larger budgets, have more contacts with the media, and have the force of combining many voices into one.
Advocate for policies that show understanding and respect for natural processes. Examples are moving to reliance on renewable sources of energy rather than harmful sources like coal, gas, and oil; phase out government subsidies for the fossil fuel industry and unsustainable industrial agriculture; stricter regulation of carbon dioxide and methane emissions; and instituting taxes on each unit of pollution produced.
Advocate for government agencies and government leaders at all levels to conscientiously try to fulfill their responsibilities toward protection and conservation of the environment.
Advocate for the United States to join with other countries around the world to attempt to reduce emission of greenhouse gases. In 1997, delegates from 161 nations met in Kyoto, Japan to negotiate a treaty to slow atmospheric warming and projected climate change. The first phase went into effect in 2005. By 2009, 187 of the world’s 194 nations had ratified the agreement, but the United States was not one of them. The more-developed countries agreed to cut their emissions of carbon dioxide, methane, and nitrogen oxide to certain levels by 2012, but they failed to do so.
In 2015, all 197 world nations (three new nations had emerged) ratified or signed a new agreement (the Paris Agreement or Paris Climate Accord) to reduce greenhouse emissions and to support a variety of regulatory mechanisms. In the Paris Agreement, each country determines, plans and regularly reports its own contribution to mitigate global warming. There is no mechanism to force a country to set a specific target by a specific date, but each target should go beyond previously set targets. However, in June, 2017, President Donald Trump announced his intention to withdraw the United States from the agreement, causing widespread condemnation both internationally and domestically. Under the agreement, the earliest effective date of withdrawal for the U.S. is November 2020. The United States will then be the only country not supporting the Agreement.
Examine the values and political position on this issue of candidates running for political office. Federal support for a strong Environmental Protection Agency is very important. Support for a meaningful Department of Environmental Quality in North Carolina is very important. Support by North Carolina’s governor and state legislature for taking a scientific approach to consideration of climate change and global warming is absolutely critical. Look for candidates that emphasize the importance of environmental impact in making decisions about what to do or not do.
Environmental Defense Fund. 2017a “Nine Ways We Know Humans Triggered Climate Change.”
Environmental Defense Fund. 2017b “Climate Changes Effects Plunder the Planet.”
Environmental Defense Fund. 2017c “Why You Need to Care About Climate Change Now.”
G. Tyler Miller and Scott E. Spoolman. 2016 Environmental Science (15th edition). Boston: Cengage Learning.
National Ocean Service. 2017 “Is Sea Level Rising?”
Alecia M. Spooner. 2012 Environmental Science for Dummies. Hoboken, NJ: John Wiley and Sons.
Read and See More on Climate Change and Global Warming:
BBC. 2017 “Six Graphs That Explain Climate Change.”
Six graphs plus explanation that together explain climate change and its harmful effects.
Jean Chemnick. 2016 “Could Trump Simply Withdraw the U.S. from Paris Climate Agreement?” Scientific American, November 10. www.scientificamerican.com/article/could-trump-simply-withdraw-u-s-from-paris-climate-agreement/
Discussion of how quickly President Trump could remove the United States from the Paris Agreement.
Charles Q. Choi. 2017 “Rising Seas Could Submerge the Oldest English Settlement in the Americas.” Live Science, November 30, 2017. www.livescience.com/61063-rising-seas-may-destroy-archeological-sites.html
Many American monuments could be submerged by rising ocean levels.
Environmental Defense Fund. 2017 “Nine Ways We Know That Humans Triggered Climate Change.”
Nine types of evidence that show that human behavior has caused climate change. Evidence is based on chemistry, chemical analysis, physics, biology, computer modeling, and scientific consensus.
Richard Hilderman. 2017 "Sea Level Rise and Why It Matters to Brunswick County."
Analysis of the danger of rising sea levels to Brunswick County.
National Aeronautical and Space Administration (NASA). 2017 “Global Climate Change: Vital Signs of the Planet.” www.climate.nasa.gov/scientific-consensus/
A summary of climate change research presented by NASA. It provides important information on climate change evidence, causes, effects, scientific consensus, vital signs, and a frequently asked questions section.
(Scholarly Article) Daniele De Wrachien and Mudlagiri B. Goli. 2015 “Global Warming Effects on Irrigation Development and Crop Production: A World-Wide View.” Agricultural Sciences. file.scirp.org/Html/11-3001166_58496.htm (go to directly; does not load)
A scientific explanation of how changing technologies and other conditions on earth will make
global warming even more of a problem in the future.
(Video) Susan Anenberg. “Effects of Climate Change on Children’s Health.”
A discussion of the impact of climate change on the health of children.
(Video) Bill Nye. “Climate 101 with Bill Nye.” www.youtube.com/watch?v=3v-w8Cyfoq8
One of many excellent YouTube videos of Bill Nye explaining climate change and expressing his frustration with climate-change deniers.
Sample of Scholarly Journals:
Global Change Biology
Nature Climate Change