Introduction
Climate change is a global issue that has generated a lot of controversy in recent years. More than any other current threat that faces us, it is likely to affect the way economic and environmental policy will be drafted. However, not all people are accepting of the fact that climate change exists, and many of those that deny it are in control of environmental legislation.
Climate change has been happening across the globe for eons, and few people disagree that this is true. However, the last hundred to one hundred fifty years has seen a dramatic increase in the rate of climate change. Most scientists believe that this is a result of anthropogenic, or man-made, activity. Among climatologists and within the scientific community, there is no doubt that climate change is occurring faster than it ever has before, and the causes of its acceleration are thought to be entirely human in origin (Lashof & Ahuja, 1990; McKibben, 2011). Climate change, or global warming, has disrupted and will continue to disrupt both aquatic and terrestrial ecosystems, threatening the lives of a sixth of all animal species worldwide by bringing about a sixth great extinction event (Leakey & Lewin, 1996). What's more, climate change poses a threat even to human survival.
The Problem and the Solution
Climate change is manifesting itself in a number of different ways that are hazardous to our human way of life. For example, climate change or global warming will increase the severity and frequency of extreme weather events, such as heat waves and hurricanes (McKibben, 2011). It has already been observed that as warmer air temperatures cause the polar ice caps to melt, sea levels have begun to rise, and ocean waters have begun to warm. These changes create optimal conditions for a surge in typhoons, cyclones, and hurricanes. As an added effect, these storm surges will cause heavy rains that extend hundreds of miles inlands, leading to floods that cost millions of dollars and destroy hundreds of lives. The recent deadly flooding in Texas which claimed nearly 30 lives in May are a testament to the ferocious power of tropical storms (Associated Press, 2015).
At the same time, as temperatures continue to rise over land, so will the intensity of extreme heat events. Dry conditions will increase, leading to droughts, heat waves, and wild fires. Each year, millions of acres of land are destroyed by wild fires, especially in arid regions like Australia and California.
Human agriculture is particularly threatened by climate change (Jenkinson, Adams, & Wild, 1991). Agriculture is dependent on certain climate conditions that global warming is bound to disrupt. Certain factors such as soil moisture, soil pH, nutrient levels, water availability, and the length of the growing season, will all be affected by global warming. Additionally, there are certain pests, bacteria, and fungi that will thrive in the warmer temperatures brought about by global warming. These changes will have a cumulative effect on agricultural productivity. In the short term, warmer weather and higher atmospheric CO2 levels may have a positive effect on productivity (Root et al., 2003). Nevertheless, in the long run, more extreme temperature fluctuations and greater precipitation rates will be detrimental to crop yield. For example, in 2008, farmers in the American Midwest lost over 8 billion dollars in farming revenue when the Mississippi River overflowed, destroying agricultural fields just before the harvest period (“Agriculture and Food Supply,” 2013).
Unfortunately, there is no silver bullet solution to climate change. Even if humans were to cease all production of greenhouse gases today, climate change would still continue far into the future. However, there are measures that nations may take to mitigate its effects and safeguard our way of life.
Five Page Outline
Slideshow Title: The Threat of Global Warming
First slide: First, we look at the causes of global warming. Global warming is a result of the greenhouse gas effect.
Each day, the earth receives energy in the form of ultraviolet and infrared radiation from the sun. This type of radiation lies outside of the visible spectrum to humans.
Clouds, the polar ice caps, and large desert regions (such as the Sahara, the Saudi Arabian Peninsula, and Australia) reflect a significant percentage of this solar radiation back out into space.
The rest of the solar energy is absorbed by the atmosphere, the land, and the oceans, and as they heat up, they emit heat in the form of infrared thermal radiation.
Gases within the atmosphere act like a blanket, absorbing infrared radiation and preventing it from going out into outer space.
The heat becomes trapped in the atmosphere, gradually warming the earth's surface.
The effect of heat-trapping in our atmosphere is known as the greenhouse gas effect
As greenhouse gases build up in our atmosphere, more and more heat is trapped
An increase in atmospheric concentrations of greenhouse gases produces positive climate forcing, which is a warming effect.
Global warming (or climate change) refers to the warming effect on the planet produced by the increase in greenhouse gases
Second Slide: GreenHouse Gas concentrations have been rising.
The main greenhouse gases in our atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone
Other greenhouse gases are synthetic chemicals that are emitted only as the result of anthropogenic activity.
Carbon dioxide accounts for most of the greenhouse gas emissions produced by the United States.
Between 1990 and 2010, the net global emissions of greenhouse gases has increased by 35 percent.
Greenhouse gases are produced naturally, but the recent increase in production has been due to human activity.
Carbon dioxide, methane, nitrous oxide, and synthetic chemicals like fluorinated gases are released by the burning of fossil fuels, the production of coal, agricultural activities, and industrial processes.
The International Panel on Climate Change has reported that atmospheric concentrations of greenhouse gases have been rising since the industrial revolution.
In 2004, the world was producing 70 percent more greenhouse gases than it was in 1970.
In 1750 at the start of the industrial revolution, the global concentration of carbon dioxide was 280 parts per million; in 2015, it is over 380 parts per million.
Third and Fourth Slides: Global warming will have many adverse effects for all life on earth.
Third Slide:
the pictures, from left to right, are:
a dried lake bed, caused by drought
a corn field suffering from poor farming conditions, such as low nutrient levels, low water retention of the soil, or pest infestation – all effects of global warming
a polar bear clinging to a melting ice floe. The habitats of polar bears and other arctic and antarctic animals is are rapidly diminishing because of global warming
Fourth Slide:
Even if we succeed in bringing down global greenhouse gas emissions and reducing atmospheric carbon dioxide concentrations, we will still feel the adverse effects of global warming for decades and perhaps centuries.
On a large scale, we can expect to face many threats to human survival, including droughts and the depletion of water resources.
For example, for the last two years the state of California has been in a state of crisis because of drought. Currently, the state is struggling to meet the water needs of its millions of acres of farmland as well as its 40 million residents.
We may be facing a global water shortage as well. The United Nations predicts that by 2030, the global demand for water will exceed the global supply by 40 percent.
Additionally, it is thought that a majority of the world's population lives within a 30-mile radius of a major watershed that is either running out or is in danger of doing so.
We are also experiencing the rapid acidification of the oceans. The oceans are a major sink for carbon dioxide, which means that they absorb a lot of the carbon dioxide that would otherwise go into the atmosphere and act as heat trapping gases.
As the oceans become more acidic, their ability to absorb carbon dioxide decreases, so even more heat will be trapped in the atmosphere.
We are experiencing a loss of biodiversity. Scientists say that we are now in the midst of the sixth great extinction. One in six plant and animal species are expected to go extinct in the near future.
Hurricanes, typhoons, and tropical storms will increase in frequency and severity due to global warming.
Warmer temperatures will lead to the melting of polar ice caps, which will in turn cause global sea levels to rise, and ocean waters to warm. This will increase the likelihood of storm surges, which will cause millions of dollars of damages to communities along the coast.
These are only a few of the foreseeable effects of climate change. There may be many other effects that have not yet been predicted.
Fifth Slide: There are many who dispute that global warming is actually happening. So how certain is global warming: Answer: it is a matter of fact that global warming is happening.
A consensus consisting of 97 percent of climate scientists agrees that global warming is happening, and its main driver is human activity.
In January of this year, the members of the United States Senate voted 98 to 1 that global warming is real, and not a hoax.
Computer simulated climate models predict that global warming trends will continue even if global emissions of greenhouse gases stopped outright.
Sixth Slide: The time to act on climate change is now.
Global warming has been known about for decades.
Since the first measurements were taken from an observatory on Mona Loa in the 1950s, atmospheric carbon dioxide levels have been steadily increasing.
The best time to act on climate change was years ago, but the second best time to act is now.
We do not have to be 100 percent certain about the effects that climate change will have before we begin preparing for them.
Most climate models have been proven to be accurate at predicting long-term change.
All countries should make steps toward reducing their national emissions levels in order to mitigate the effects of global warming.
Individuals can help reduce their own emissions by making small changes to their energy consumption patterns at home.
There are a number of “green” technologies for home use such as low-flow toilets, solar panels for electricity, energy efficient lightbulbs, and low-emissivity windows that consumers can use to replace older, less efficient house fixtures.
References
Associated Press. (2015). Several North Texas Roads Remain Flooded. NBC. Retrieved from http://www.nbcdfw.com/news/local/List-of-Flooded-Roads-and-Highways-308886211.html
Jenkinson, D. S., Adams, D. E., & Wild, A. (1991). Model estimates of CO2 emissions from soil in response to global warming. Nature, 351(6324), 304-306.
Leakey, R., & Lewin, R. (1996). The sixth extinction: biodiversity and its survival.
Lashof, D. A., & Ahuja, D. R. (1990). Relative contributions of greenhouse gas emissions to global warming.
McKibben, Bill. (2010). Eaarth: Making a life on a tough new planet. New York: St. Martin's Griffin.
Root, T. L., Price, J. T., Hall, K. R., Schneider, S. H., Rosenzweig, C., & Pounds, J. A. (2003). Fingerprints of global warming on wild animals and plants. Nature, 421(6918), 57-60.
United States Environmental Protection Agency. (2013). “Agriculture and Food Supply.” Retrieved from http://www.epa.gov/climatechange/impacts-adaptation/agriculture.html
