Global Warming and the Paris Agreement

GLOBAL WARMIN GAND TH EPARIS AGREEMENT ) 0 . 2 y b C C ( a n a c i x e M a c i l b ú p e R a l e d a i c n e d i s e r P / s n o m m o C a i d e m i k i W Delegates to the 2015 United Nations Climate Change Conference, from which the Paris Agreement emerged. There is little doubt that the Earth is warming. But there is The Evidence of Climate Change considerable controversy over global warming’s future im - To be sure, there are a number of ways that the Earth pact on the world’s climate and what we should do about it. can become warmer naturally. Periods of global warm - Researchers at the University of Alaska, University of ing in the past were caused by changes in the Earth’s Washington, and the U.S. Geological Survey reported in orbit, volcanic eruptions, and variations in the Sun’s ra - 2015 that Alaskan glaciers had been sending 75 billion tons diation output. But natural causes apparently cannot ex - of water into the sea every year for 19 years. A consensus plain the current warming of the Earth. of the world’s scientists (almost all scientists) has con - In 1988, the United Nations established the Intergov - cluded that changes in the environment like this one pro - ernmental Panel on Climate Change (IPCC). The purpose vide convincing evidence of a gradual heating up of the of the IPCC is to review the work of scientists around the Earth’s surface. Scientists refer to this as “global warming.” world to assess the evidence of climate change that re - For over 100 years, scientists have known about the sults from global warming. physical mechanism that causes the Earth to warm. The IPCC found that during the 20th century, the Today, they call it the “greenhouse effect.” Generally, it Earth warmed by about one degree Fahrenheit. One works like this: degree does not seem like a lot. But scientists know 1. Radiation from the Sun in short wavelengths easily that at various times in Earth’s history, shifts of just a passes through the Earth’s atmosphere and strikes few degrees had a dramatic impact on the planet’s cli - the surface, which reflects much of it back as longer mate and environment. wavelengths. In 2014, the IPCC issued its fifth report. The IPCC 2. Instead of going back into space, the longer wave - found that the concentration of carbon dioxide in the at - lengths are absorbed by gases in the atmosphere. mosphere rose by about 30 percent during the last 200 3. The atmosphere reflects back to the Earth’s surface years, the period of the Industrial Revolution. Carbon a significant amount of the trapped radiation, which dioxide is the most important greenhouse gas that traps becomes heat. heat from the sun. Thus, the Earth warms much like a greenhouse or In addition, the IPCC discovered “new and stronger automobile does when the Sun’s rays penetrate the glass, evidence that most of the warming observed over the but are trapped inside as heat. last 50 years is attributable to human activities.” About Water vapor and other gases in the atmosphere cap - 75 percent of carbon dioxide emissions come from burn - ture and return to Earth about 50 percent of the Sun’s in - ing fossil fuels. coming radiation. The warming that results is necessary China is the largest producer of carbon dioxide emis - to prevent our planet from becoming extremely cold and sions. In 2015, China emitted over 10 million kilotons of hostile to life. But over the past few centuries, human carbon dioxide, or 29 percent of global emissions. The activities on Earth have increased the concentration of United States is the second largest producer, emitting some gases in the atmosphere that intensify heating. about half the amount of carbon dioxide that China These gases include carbon dioxide, methane, nitrous emits. Americans are responsible for 35 percent of all oxide, and others, the so-called “greenhouse gases.” greenhouse gases ever produced by humans. BRIA 34:1 (Fall 2018) U.S. GOVERNMENT/CURRENT ISSUES 9 © 2018 Constitutional Rights Foundation U The Greenhouse Effect n i t e ‘Climategate’ d S t In 2009, hackers leaked a t e s emails from the Climatic Re - E n v i search Unit (CRU) at a uni - r o n m versity in Great Britain. The e n t a IPCC partly relied on infor - l P r o mation from the CRU. Of the t e c t more than 1,000 emails, one i o n A mentioned that “we can’t ac - g e n count for the lack of warm - c y ing at the moment.” Another referred to a “trick” to “hide the decline” in temperatures in one particular data set. In several emails, scientists de - bated with each other about technical aspects of inter - preting data. The leaking of the emails was dubbed “Climategate” in Most of the remaining carbon dioxide emissions re - the press. Many people including a few scientists re - sult from the destruction of forests. Since 1855, humans sponded by calling global warming a “hoax.” S. Fred have destroyed up to 20 percent of the world’s rain Singer criticized the CRU and the IPCC due to al - forests in places like Brazil. Burning forests to clear land legedly “distorted raw data” revealed in the emails. for farming, roads, and settlement injects large amounts U.S. Senator James Inhofe (R-OK) argued that the of carbon dioxide into the atmosphere. Also, trees con - emails revealed “a fractured consensus on the state of vert carbon dioxide into oxygen through photosynthe - climate science.” sis. With the destruction of trees, however, less carbon Analyses in news sources such as The Guardian and dioxide is converted. The New York Times demonstrated that the question - The Persistent Minority able emails were taken out of context. The word “trick,” About 97-98 percent of climate scientists – a sci - for example, was just a colloquial word for a technical entific consensus – agree with the IPCC that today’s way of compiling data. But the persistent minority had global climate change is happening and is primarily found evidence to be skeptical of the data used by most human-caused. A small but persistent minority of the climate scientists. world’s scientists, however, disagree with the con - What If We Do Nothing? sensus around the IPCC’s findings. What is likely to happen over the next 100 years if These dissenting scientists deny the IPCC’s find - we do nothing about global warming? The IPCC’s fifth ings in a variety of ways. Most of them doubt that assessment report in 2014 includes the best available pro - global warming is primarily human-caused. Others jections of likely impacts on the world’s environment. believe the cause of global warming cannot be known. According to the IPCC: Still others simply doubt that the effects of global • Global temperature will rise 4˚C (Celsius) by the warming will be catastrophic. year 2100 if carbon emissions into the atmosphere Physicist S. Fred Singer is skeptical of anthro - continue at their present rate. Climate changes in pogenic (human-caused) climate change. In 2013, he the 21st century are very likely to be larger than said, “The Sun . and other natural forces are much those in the 20th century. more important than any human influence on cli - • Increasing temperatures will mean more droughts mate.” He has also pointed out that scientists are not in many areas of the world, including parts of the sure how much carbon dioxide is absorbed by the United States, such as the Southwest. In these areas, world’s oceans. crop yields will decline and more forest fires will Singer has also identified global warming’s potential occur. The decreased food supply will especially af - benefits, if temperatures rise. He foresees more food from fect the urban poor, creating “hotspots of hunger.” longer growing seasons, an increase in timber, more • While some parts of the world will suffer from heat water in some dry regions, and a decrease in the use of and dryness, other regions will experience extreme fossil fuels for heating as winters become more moderate. US HISTORY 10 U.S. GOVERNMENT/CURRENT ISSUES BRIA 34:1 (Fall 2018) © 2018 Constitutional Rights Foundation rainfall along with floods, landslides, and soil ero - ice sheet could melt away entirely, adding to the pro - sion. Violent storms will threaten human life, health, jected three-foot rise in sea level by 2100. and property, driving up insurance rates. The National Oceanic and Atmospheric Administra - • Anthropogenic influence has contributed to the tion reported that hurricanes, floods, wildfires, and tor - melting of the Greenland ice sheet since 1993. nadoes have increased alongside record-setting warm Global sea level rise will very likely increase at a temperatures in the United States. The damages cost over faster rate than what scientists observed between $300 billion in the U.S. in 2017 alone. 1971 and 2010. Rising seas will cause major flood - As noted by Singer, there could be potential positive ing and loss of land in the coastal regions in the benefits from global warming, such as longer crop growing world, affecting tens of millions of people. periods. But these benefits will probably not be enough to • Ecosystems unable to cope with the climate changes overcome significant damage to the environment. will be at risk. While some animal, bird, and fish What Should the U.S.

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