Effects of Global Warming on Wildlife and Human Health
Jennifer Lopez
Editor Werner Lang Aurora McClain
csd Center for Sustainable Development I-Context Challenge
2 1.2 Effects of Global Warming on Health
Effects of Global Warm- ing on Wildlife and Human Health
Jennifer Lopez
Based on a presentation by Dr. Camille Parmesan main picture of presentation
Figure 1: Earth from Outer Space.
Introduction of greenhouse emissions.”4 Finally in 2007, the Fourth IPCC Assessment report concluded Global warming is defined as “the increase that the “warming of the climate system is un- in the average measured temperature of the equivocal” and “is very likely [> 90% sure] due Earth’s near surface air and oceans”.1 For the to observed increases in anthropogenic green- past several decades scientists have docu- house gas concentrations.”5 Based on these mented multiple aspects of climate change, conclusions, many scientists and environmen- including rising surface air temperature, rising talists have focused their efforts on sustainable ocean temperature, changes in rain and snow- living and are pushing for energy alternatives fall patterns, declines in permanent snowpack which produce little or no carbon-dioxide to and sea ice, and a rise in sea level.2 Through reduce greenhouse gas emissions. their research, scientists have been able not only to document changes in climate and the Effects of temperature change physical environment, but have also docu- mented effects that this phenomenon is having Scientists have concluded that in the past 100 on the world’s ecosystems and species, many years, the Earth’s average air temperature has of which are negative. risen 0.74°C (See Figure 2). This graph indi- cates that the temperature has been steadily Although global warming can occur naturally rising since about 1975. It may not seem like a as a result of variation in the amount of solar big change because the overall number is low, energy reaching the earth, the Intergovern- but in fact, this rise has had a dramatic effect mental Panel on Climate Change (IPCC) on the environment and its inhabiting species. has concluded that climate change of the Of some 1592 species observed, 41% have past 30 years is largely attibuted to a human- shifted their ranges toward higher elevations or caused increases in greenhouse gas emis- closer to the poles, while another 62% showed sions.2 As the research has progressed, the some sort of shift to earlier spring breeding, concern about greenhouse gas emissions migrating, leafing, or blooming.6 Additionally, has increased. In 1995, the Second IPCC every major group that has been studied, Assessment Report stated that “the balance of whether trees, butterflies, mammals, birds, evidence suggests discernable human influ- amphibians, fish, or marine coral, has been ence on global climate change.”3 In 2001, the affected in some way. 7 Third IPCC Assessment concluded that “most observed warming is likely due to the increase Global warming has affected more than just
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animal species. The increase in ocean and air temperatures has also affected the Earth’s ice caps and glaciers. According to the World Meteorological Organization, in 2007 “a record low Arctic sea ice extent was observed which led to the first recorded opening of the Canadian Northwest Passage.”8 Additionally, “the largest single block of ice in the Arctic, the Ward Hunt Ice Shelf, had existed for 3000 years before it starting cracking in 2000. Within two years it had split all the way through and is now breaking into pieces.”9 Figure 3, taken from NASA satellites, depicts the shrinking of the Arctic ice cap as a whole. Scientists estimate that it has shrunk by about 20% since 1979.9
A reduction of twenty percent over 30 years averages to a rate of more than 6% per de- cade. If this rate continues, the polar ice cap will no longer exist at the end of the century. Melting glaciers are expected to contribute to sea level rise over the next few centuries. Even recent sea level rise, which to date has largely been due to expansion of the water as Figure 2: Instrumental temperature record it warms, has been sufficient to cause prob- lems in low-lying coastal regions. Rise in sea levels is a problem because it increases beach corrosion, coastal flooding, and contamination of freshwater supplies.9 In 2001, an EPA study suggested that a rise in sea levels of 3 feet (a level for 2100 projected by multiple studies) would “inundate some 22,400 square miles of land along the Atlantic and Gulf coasts of the United States, primarily in Louisiana, Texas, Florida, and North Carolina.”9 Although the observed rise in the Earth’s temperature might seem slight, the effects are already apparent, and will become increasingly dramatic.
Effect of global warming on species
Global warming has proven harmful to many of the Earth’s species. Changes in tempera- ture, rainfall and snowpack are affecting the way that many species live. Many are moving closer to the poles as the more equatorial parts of their range become climatically unsuit- able, while others that live in mountain areas are moving to higher altitudes. A recent study of nearly 1,600 species of plants and animals Figure 3: Decrease in Polar Ice Caps. The red line shows the summer Artic ice boundary in 1979. Image was taken in 2003. discovered movement toward the poles at an average rate of 3.8 miles per decade.6 For instance, the purple emperor butterfly, which Sea.10 With glacial retreat in the Andes, three clines in winter sea ice habitat.”12 Many of the historically only went as far north as Esto- species of frogs, along with their parasitic fun- tiny organisms that the penguins feed on, like nia, has now begun inhabiting Sweden and gus, have shifted 400m higher in altitude over krill shrimp, feed off of the algae. It is believed Finland. Their rate of colonization has been the past 70 years.11 that shrinking sea ice has led to declines in rapid, a 100km expansion in just three years.4 algae, which in turn has led to a decrease in A warm-adpated group of marine copepods, Although some species have successfully krill shrimp, and thus a decline in the penguins’ which once only went as far north as the shifted where they live and adapted to new food supply.13 Additionally, polar bears have Northeast Atlantic, has shifted up to 1000km areas, others have not. For example, “over even been drowning due to the longer swim northward over the past four decades and now the past 25 years, some Antarctic penguin lengths they must endure between ice flows.12 is abundant in the northern part of the North populations have shrunk by 33% due to de- Also, the thinning of the ice caps “leaves fewer
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places for both the polar bears to hunt [for seals] and the seals to raise their young.”13 Because polar bears need “2kg of fat per day,” land animals and berries will not be enough to keep them alive, thus they need an abundance of high fat foods, such as seals, for continued survival.2
However, the most negatively affected ter- restrial species have been high elevation cloud forest frogs. Of these, 74 species have become extinct over the past 30 years.14 Their extinctions are believed to be linked to climate change, because most have occurred only at particular elevations, and in relatively undisturbed areas. “According to this recent study, Earth’s rising temperatures are altering both temperatures and cloud cover on tropical mountains, leading to cooler days and warmer nights, both of which should favor the chytrid fungus, based on lab studies which indicated that the fungus grows and reproduces best Figure 4: High elevation cloud forest frog Figure 5: Mosquito penetrating human flesh at temperatures between 63 to 77° F (17 to 25° C).”15 Some scientists believe that climate Mosquitoes carrying malaria were found at Once again, the species most affected are change has improved conditions for this previously unobserved elevations on Mount the amphibians, with a nearly 30 day shift in fungus at elevations where it previously non- Kenya in 2006. As the temperatures rise, dates.5 optimal climatically, and that these changing higher elevations become more hospitable conditions for the fungus has caused many for mosquitoes and more dangerous for local This change in seasonal timing is also affect- species of frogs to become extinct. inhabitants.”16 ing seasons for human activities, crops, and vegetation. In one recent article, maple syrup Effects of global warming on human and These are not the only incidents recorded, producers in New Hampshire were blaming animal diseases nor will they be the last. Global warming will global warming for their earlier tap seasons. continue to have a negative effect on human Producers claimed that “they [were] tapping Global warming will not only affect what spe- life. However, these effects will not always their trees about a month earlier than their cies eat and where they live, it will also affect be direct. Humans will also be at risk due to ancestors did.”18One producer claimed that the their health, including that of human beings. severe weather and flooding caused by the maple syrup season began to change about Some of the widespread health problems changes in temperatures and sea levels. 20 years ago and that the tapping season projected to affect humans are “devastating Additionally, humans can be affected by what shifted from March to February during the last heat waves, poisonous plants producing more they eat, as is the case with foods like oysters, century. The rise in temperatures is so drastic potent toxins, air quality plummeting on sum- which can contain deadly bacteria in warm that nature is beginning to react to the change, mer days, disease-carrying insects swarming waters. Several studies have explored the which is understandable when natural occur- mountain villages, and an increase in allergies prevalence of this problem. The bacterium is rences that once took place in March are now and asthma.”16 Some health statistics are as found in marine and estuarine environments happening in February. follows: and thrives in warm seawater since it requires salt for growth.17 Of all the cases of infection Warmer winters have also caused moth and “In the summer of 2003, an intense heat wave by the vibrio vulnificus bacterium from the Gulf beetle populations to expand and to shift was blamed for an estimated 35,000 deaths of Mexico, 89% occurred in humans eating toward the poles. “Extended growing sea- across large swaths of Europe. A study says seafood (primarily oysters) that were caught in sons have resulted in increased forest pest that global warming has doubled the likelihood warm waters. For patients admitted to hospital, outbreaks and loss of wood productivity.”2 The of heat waves of this magnitude. the mortality rate was 30-48%. A continued rise most notable example of this phenomenon in sea temperatures is expected to increase is the Spruce bark beetle epidemic that has In 2008 scientists found that poison ivy vines outbreaks of vibrio vulnificus, thus increasing killed some 3.8 million acres of trees in Alaska. have grown 10 times denser near Savannah, the number of humans affected by the disease. Growths of Mountain pine beetles in Colorado Georgia, over the last 20 years. Increased and British Columbia and of pine procession- carbon dioxide in the atmosphere causes ary moths in Italy and France have also dam- poison ivy to grow larger and produce stronger Effects of global warming on seasons aged large stands of timber.7 irritants. The changes in Earth’s temperature are also Six young men and boys were killed by fatal Projected impacts of global affecting the world’s seasons. Animals are parasites in 2007, after they swam in water breeding earlier than before, and trees, shrubs, warming at Arizona’s Lake Havasu that was infested and plants are blooming and leafing sooner with a heat-loving amoeba. The Centers for Global warming is just beginning, and will than they used to.7 Figure 6 best illustrates the Disease Control and Prevention expect more only worsen if alternatives are not imple- change in spring dates of different species. of these illnesses as global temperatures rise. mented. From this report, one can begin to
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understand the magnitude of the impact that climate change has had on the environment and its inhabiting species. These results have occurred without even a full 1° C rise in temperature. What will become of the world mean 2.8 if the temperature continues to rise? Will the days/decade Earth and its ecosystems be able to adjust? advance Many Researchers and scientist believe that they may not.
Some scientists predict that a 2°C increase in temperature would cause an overall “projected extinction of 20% of species worldwide.”2 There would also be an increase in the Figure 6: Trends in timing of spring events among northern temperate species incidence of tropical diseases, which would lead to an increase in the number of human deaths wolrdwide. Additionally, there would be a decline in the production of agriculture and farming at lower latitudes, and an increase in production for higher latitudes, i.e. Canada.2 Large concentrations of tundra and sea ice habitats would likely become scarce, thus leading to extinction or near extinction of many of polar animals such as polar bears, seals, and caribou.2
To emphasize the negative effects of global warming further, scientists also predicted the impacts of a 4°C rise in temperature. At this level, the world would begin to see mass extinctions of species, up to 70% of those cur- rently existing. A complete loss of suitable cli- mate space for a large number of species and ecosystems would also be likely.2,19 The coral reefs of the world would likely become extinct because of the rise in ocean temperatures and increasing ocean acidity due to increased carbon-dioxide. As a result, both tourism and fishing industries would be negatively affected.2 Furthermore, agriculture production would decline for all latitudes throughout the world. This decline in production would result Figure 7: IPCC Time to Reach CO Equilibrium in a large reduction of the food supply for the 2 world’s population; subsequently the world’s population would suffer increased malnutrician and even starvation. oxide or other substances that cause warming. emitted into the atmosphere, they each raise Recommendations for reducing One way to reduce greenhouse gases is to other issues that must be considered. For global warming use alternative energy sources. For instance, instance, the use of nuclear power brings up switching the fuel used in power plants from questions about where and how the waste coal to gas would decrease the amount of CO would be stored. Some places would be Global warming is affecting the Earth at an 2 alarming rate and changes must be made to that is released into the atmosphere. Other opposed to storing waste in their nearby sur- reduce these effects. Although adaptation can forms of power could come from renewable roundings. Others would be concerned about occur within a margin of +2°, beyond that, it sources such as wind, solar, and hydroelectric attacks on the power plants themselves or on becomes increasingly unlikely. The only way power. The use of nuclear power, which has the waste sites. Wind power also introduces to prevent an increase of this magnitude is to proven successful in Europe, could also be problems. Already, rare and endangered spe- 2 decrease the emission of greenhouse gases. considered. Most biofuels actually emit more cies have been hurt and killed by windmills. Scientists believe that greenhouse gases are carbon during farming and energy-production The windmills pose a threat to birds, especially the primary cause of temperature increases, processes than they capture through plant during migratory seasons. Additionally, some so to combat the problem, society must find growth, and so should be considered on a birds mistake the shadows of the mills for 2 ways to reduce greenhouse gases through case-by-case basis. larger predators and thus do not nest near 2 conservation and use of those renewable them out of fear of being destroyed. sources of energy which do not emit carbon-di- Although using these forms of energy would decrease the amount of greenhouse gases
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Energy efficiency and conservation are an make use of natural lighting and thermal or 8. Nodvin, Stephen C. (Lead Author); Kevin essential pat of any strategy for reducing the solar energy. New construction should comply Vranes (Topic Editor). 2008. “Global warm- emission of greenhouse gases. Improved with LEED and other energy related standards ing.” In: Encyclopedia of Earth. Eds. Cutler J. efficiency of home appliances and cars is and all appliances need to be energy efficient. Cleveland (Washington, D.C.: Environmental one way to reduce the effects. Also, knowl- It is the responsibility of professionals to Information Coalition, National Council for edge about conservation and consumption educate owners and clients about the use of Science and the Environment).
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18. Associated Press. “Warming Trend Blamed References for Syrup Season Change.” The Boston Globe.
Figure 1: NASA.gov Biography
Figure 2: Instrumental Record of Global Dr. Camille Parmesan is an associate profes- Average Temperatures as compiled by the sor in Integrative Biology at the University of Climatic Research Unit of the University of Texas at Austin. Dr. Parmesan received her East Anglia and the Hadley Centre of the UK PhD in Zoology from the University of Texas in Meteorological Office. Data set TaveGL2v was 1995 and then did a post-doc at the National used. The most recent documentation for this Center for Ecological Analysis and Synthesis, data set is Jones, P.D. and Moberg, A. (2003) Santa Barbara. “Hemispheric and large-scale surface air temperature variations: An extensive revision Parmesan‘s early research focused on multiple and an update to 2001”. Journal of Climate, aspects of population biology, including the 16, 206-223.
Figure 6: Trends in Timing of Spring Events. Parmesan, Camille. 2007a.
Figure 7: Time to Reach Equilibrium. Source: Intergovernmental Panel on Climate Change (IPCC)
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