Global warming and climate change controversy is a disagreement on the nature, causes, and effects of anthropogenic activities on the global climate and the policies that should be adopted so as to mitigate the negative effects of climate change. There is however general consensus that there is a stable warming long-term trend on the earth’s surface. Regarding causes of global warming, the issue is whether the rise in global average air temperature in a warming trend is a normal variation or human activities have contributed to it and also whether it is as a result of errors in climate measurement. Controversy is mostly in the general media as well as within the scientific arena. Mainstream scientific organizations around the world such as IPCC, Royal Society, and American Meteorological Society among others agree with the review that for the last 50 years a warming trend being experienced is a result of increased concentration of Greenhouse gases from human activities. Most world governments and political figures seem to agree with this assessment with some calling for immediate and decisive action to curb the warming and others undecided on the actions to take. There is however a small vocal section of both scientists (individual and organizations) and the general public referred to as ‘global warming skeptics’ who disagree with this assessment. These include the Australian APEC Study Center, international policy network (UK), Friends of Science (Canada) among others.
This research will counter the line of argument by skeptics that there is no conclusive evidence that climate change is happening. One of the counterarguments to support this view is offered by ‘trend skeptics’ who say that warming is due to the ‘urban heat island effect’ in the measurements and not necessarily a stable trend in global temperature increase.
Introduction
Global warming refers to an average rise in the earth’s surface temperature as a result of the greenhouse effect, which in return causes climate change and other consequences on the earth. This happens when solar radiation reaches the earth’s surface by penetrating through the atmosphere, which is then absorbed resulting in surface warming. Most of this absorbed energy is radiated back to the atmosphere in longer infrared wavelengths where it is trapped and redirected back to the earth’s surface by molecules in the earth’s atmosphere. These molecules are referred to as greenhouse gases and have made life possible on earth through this phenomenon by making the earth about 600F warmer. However, the increased concentration of these gases has caused increased trapping of infrared radiation causing more warming of the earth’s surface. Climate change on the other hand is the long-term variation in the average weather patterns of a region (Scientific Evidence).
Scientific evidence to prove that temperatures have risen as a result of the greenhouse effect has already been done through the study of ancient ice cores from Antarctica (Blaustein and Dobson 63). Comparison of the trend of dominant greenhouse gas i.e. Carbon dioxide with temperature differences of the past 400,000 years shows that there is a firm connection between their performances. During the industrial revolution in the 1800s, evidence shows that suddenly atmospheric concentrations of carbon dioxide began a rising trend from 280ppmv and attained to the current 376ppmv. This rise is higher than the previously attained concentration in the preceding 400,000 years by 77ppmv. This upward trend scientists attribute to anthropogenic activities. UNEP jointly with World Meteorological Organization (WMO) came up with the Intergovernmental Panel on Climate Change (IPCC) in 1988 because of this.
The IPCC reported in its Second Assessment Report in 1995 that carbon dioxide concentration has increased over the past 150 years from 280ppmv to 376ppmv. This, the report attributed to human activities. The model used also forecast a 1.8 to 6.3 degrees Fahrenheit rise in the global mean temperatures in the next century and a sea-level rise of 6 inches to 3 feet at about the same time (Blaustein and Dobson 85). The conclusions drew support from 2600 scientists by 1997. However, this view that the globe is warming steadily in the past century have drawn a lot of disagreement on the nature, causes, and effects of anthropogenic activities on the global climate and the policies that should be adopted to mitigate the negative effects of climate change both in the general media and scientific arenas. Mainstream scientific organizations and a majority of governments around the world support the assessment that for the last 50 years, a warming trend has been experienced and that the causes for this are an increased concentration of greenhouse gases from anthropogenic activities. A small but vocal number of scientists and individuals are in disagreement with this review. They cite several arguments one of them being that there is no conclusive evidence that global warming is happening. This essay is going to give strong and conclusive evidence to support the assessment that global warming is happening and clear and undeniable ways.
Warming of the seas around the poles
There is conclusive evidence to show that global warming is happening in the recent scientific evidence that the poles are warming. The intergovernmental Panel on Climate Change projected in 2001 that the sea level will increase with an average of 11cm to 77cm by 2100 and that Antarctica’s contribution to this rise will be to a small extent. Studies have however found out that melting Antarctica ice is contributing 15% of all sea level rises of about 2mm a year. This shows that warming is happening even faster than it has been predicted. Major ice shelves of Antarctica have broken off in recent years. In 1995 Larsen A ice sheet of about 1,600 sq km disintegrated then the 1,100 sq km Wilkins ice shelf and the 13,500 sq km Larsen B shelf followed suit in 1998 and 2002 respectively (World Wide Fund for Nature).
Furthermore, a study by scientists from the British Antarctic Survey (BAS) established that 13,000 square kilometers of sea ice in the Antarctic Peninsula has already melted in the past 50 years (Harden 54). They also report that the flow of glaciers into the ocean is six times faster than it was 50 years before due to the melting of ice shelves that held it back. Further evidence shows that the situation in the Arctic is even more worrying than in Antarctica. Two model studies by different researchers at the National Center for Atmospheric Research and the University of Arizona project that temperatures will increase by 3-50C by 2100 (Harden 55). The foundation for these studies was data from coral reefs, ice cores and output from NCAR and other natural climate records. All this evidence shows that indeed the earth is warming and humans must start acting or find another planet to move to.
Coral reefs
Evidence that global warming is happening is further given by the current health of the world’s coral reefs. A healthy coral reef is filled with life and colors as huge populations of a diverse species of fish and invertebrates inhabit them. They are home to dense and diverse communities of animals which are easy to see. However, scientific evidence show that we have few of these remaining corals and even fewer in such pristine condition; that corals and fishes have become less and less abundant in the last few decades. Surveys done from 1960s and early 1970s by both governmental and scientific organizations such as the Australian Institute of Marine Science’s on the corals around the world show that there is widespread coral loss. Even in the most protected, isolated and extensively managed reefs such loss is also common. The Florida Keys coral reefs declined by approximately 8% by 2006 and the Pacific coral cover is approximately 30% (Bruno 65). This loss has mainly been attributed to human-induced climate change through three mechanisms; coral bleaching, coral diseases and ocean acidification.
Coral bleaching happens when ocean temperatures rise by a degree or two and upset the delicate balance in the symbiotic relationship between the Zooxathellae and coral host that are the foundation for coral ecosystems. This leads to expellation of the zooxathellae and subsequent death of corals. An example of coral bleaching phenomenon was experienced during the El Nino of 1998 when especially warm summer was experienced in the western and Indian Oceans where the Maldives coral cover reduced to 5%.
Coral diseases are also magnified during ocean warming due to psychological stress corals are experiencing and compromise in their immune system making them more susceptible to infectious diseases. Warmer temperatures favor growth of fungus and bacteria. These result into widespread coral deaths. One such disease is the white syndrome on the Great Barrier Reef which has increased in the recent years (Bruno 70).
Polar bear predicament
The predicament facing polar bears is evidence that global warming is happening and with devastating effects. Polar bears are adapted to live in freezing conditions due to their two layers of fur and body parts designed to avert any heat loss. They also spend most of their existence in the ocean rather than land where they hunt. They are suited to this arctic climate such that a warmer climate would make them overheat. This means that if arctic climates become a little warmer the polar bear will be unable to survive as it has been happening in recent years due to global warming and subsequent climate change. As ice melts polar bears loose their habitats and experience environmental stress in finding food and shelter for breeding a fact attributing to 30% decline in their population over 30-50 years according to projections by the polar bear specialists from the World Conservation Union. The group had also suggested in a meeting in July 2005 that the polar bears be classified as vulnerable species for special protection. This suggestion is also being considered by the U.S Fish and Wildlife Service who wants polar bears be declared as endangered Species (Harden 95).
A good sign to show that global warming is the cause of the current predicament of polar bears comes from Hudson Bay, Canada. Researchers from Canada have reported that in the last 10 years polar bears have declined by 17% from 1,200 to around 1,000. This was found out to be due to ice break up which cause bears to swim to greater distances and eventually drown. Melting of ice three weeks earlier than 30 years ago during summer also means that they loose critical time of the year for feeding on seal pups on ice when they are in plenty. This feeding period enables them to store up fats to use during the four months they live onshore leading to loss of about 15% weight which, in return affect breading and swimming abilities the research concluded. The situation is described as equally grim in Alaska especially in the Beaufort Sea Region where bears are forced to live on land for longer periods and live on village dumps causing conflict with people living in these settlements (Scientific Evidence).
Rising oceans
Global sea level rise is evidence that global warming is happening. Scientific evidence show that glacier is retreating in five continents. Further, the Army Corps of Engineers research center sea observatory indicates that sea level is rising at the rate of one and half feet per century which, satellite images indicate are close to global rates in seal level rise. A 1mm rise in sea levels has result in 1.5 m retreat of the shoreline along fairly flat coastlines. This is proved by US’s Gulf coast of Florida where dead cabbage palms at the seaward edge of the salt marsh are an indication of the rising sea levels. Additionally, vacation houses have been submerged and erosion is thinning out beaches along the Atlantic coast of USA. This has resulted to intrusion of salt water into ground water especially in the highly populated coastal river deltas (Shwartz 8).
In low-laying pacific island nations, the sea level is also rising with island nations becoming submerged and salty ocean water contaminates their drinking water sources. One such island nation is Tuvalu that is between Australia and Hawaii. It is 15m above sea level on average and low land flooding and salt water intrusion contaminate drinking water and affect food production. Experts say that the island will be submerged in the next 50 years. Other islands under threat are the Maldives, Cook Islands and the Marshall Islands which have lost quiet a substantial percentage of their beachfront. There is plenty of evidence that indicate that global warming is causing oceans to rise as ice sheets and glacier melts. The shrinking sea ice and permafrost is proof as observed around Shishmaref in Alaska which is just below the Arctic Circle, where severe beach erosion has happened. Shishmaref also remains ice free a few months longer that it used to be twenty years ago thereby making this village experience fall storms (Harden 104).
Global warming and fisheries
Global fisheries are a clear indication that global warming is happening. Fish are very sensitive to temperatures in their surroundings and a small change in this causes environmental stress which can lead to death or shifts in fish populations. Fish are unable to maintain constant body temperatures and therefore their body temperatures are the same as the water they are in. if the fish encounter temperatures outside their range, either they slow down metabolism if the water is cold or if warmer their metabolism speeds up and require more food and oxygen to maintain. Scientific studies shows that fish and algae populations in major lakes in the tropics is shrinking a fact scientists attribute to rising air and water temperatures. One such lake is the Tanganyika where a report published in the Journal Nature outlined that climate change in the region has put the lake ecosystem under threat as shown by decreasing fish stocks which, have reduced by 30% over the last 80 years (World Wide Fund for Nature).
Researchers from Cemagref have been studying the effects of global warming on the marine atmosphere and majoring their research in the fish world and found out that, the number, size and representativeness of fish species have changed dramatically over a period of about 20 years. Fishermen in the same area have also observed that the fish they are catching today are not the same as before. New species from the warm waters or the Southern waters have migrated to replace the traditionally resident species. A large scale analysis by researchers at Istitut de Recherche Pour le Developpement (IRD) on several sites and streams in the same region for 15 to 25 years have found out that the structure of the fish communities have changed, a fact attributed to global warming (Blausteinm and Dobson 120).
Global warming and ecosystems and species
Ecological changes being experienced around the world is a clear indication that global warming is happening. Ecosystems are diverse networks of interrelationships and dependencies between species and their environment that have developed over a long period of time. Climate change has occurred rapidly in the last century a fact attributed to global warming. This is has upset the delicate balance that bids this ecosystem together in a pace that outstrips the evolutionary adaptation by far. Hundreds of plants and animal species around the world have been affected. Scientists have discovered that birds are laying eggs earlier than normal, plants are flowering earlier and mammals are coming out of hibernation earlier than is the norm. A team of scientists from Stanford’s Institute of International Studies (IIS) analyzing 143 scientific studies and a total of 1,473 species of animal and plant species found there is a direct correlation between global warming and biological changes. In some of these studies for example it was revealed that temperature increases in the latest decades led to some species began breeding and migrating earlier than before while in some researches, certain species have migrated poleward or to higher elevations where it was too cold for them to survive before. All these changes have been observed when the temperatures have risen by an estimated average of 1 degree F over the past 100 years. This means that far more-reaching effects are on the way as temperatures are estimated to rise by 11 degree F by 2100 according to the above analysis.
Another research on aquatic ecosystems and global climate change done by a team of scientists and released by Pew Center on Global Climate change in 2002 shows similar results. In this review of 145 scientific studies they report that aquatic ecosystems have been substantially disrupted by increases in average temperatures. Fish that thrive in cold water such as trout and salmon was indicated to be migrating northward and southwards towards the poles. Warm water environment fish such as mouth bass and carp have also been observed to expand their geographical ranges throughout the USA and Canada. All this leaves no doubt that global warming is happening (Shwartz 30).
Global warming skeptics urge that no global warming is happening and that the warming trend experienced from 1980 to 2002 is as a result of ‘urban heat island effect’ (UHI). The Urban Heat Island effect is caused by higher temperatures experienced in urban areas as a result of buildings, concrete, asphalt and human and industrial activities going on in these areas which produce more heat than their surrounding countryside. This phenomenon results in a microclimate around the city and some scientists and groups attributes this to warming trend to urban heat island as cities grow bigger in size and number. One such city experiencing this is Los Angeles in US which have experienced temperature increases of approximately 10F every decade since the World War II era when it began its mammoth growth. Other cities have experienced an average of 0.2 to 0.80F increase in temperatures each decade. Some scientists such as Ross McKitrick an economist from the University of Guelph and Patrick Michaels an environmentalist from the University of Virginia say that surface temperatures have been made hazy by their being taken in proximity to urban areas experiencing UHI effect (Inhofe 76).
Conclusion
There is strong and conclusive evidence to support the assessment that global warming is happening. First, the warming of the seas both at the Antarctica and arctic circles as shown by broken ice shelves such as the Larsen A and B and the Wilkins ice shelves and the increased speed of the flow of glacier into the oceans proves this fact. Secondly, the health of the world’s coral reefs is deteriorating as the vibrant life found in them becomes less and less common even on the extensively managed and protected coral reefs around the world. This has been attributed to coral bleaching, coral diseases and acidification of the oceans as they are triggered by temperature increases and carbon dioxide concentration rise in case of acidification. Thirdly, polar bears are under threat as their habitats are destroyed by melting ice and rise in ocean level. This has brought about environmental stress which has made it difficult for polar bears to get food, reproduce and even survive. Fourthly, global sea levels are rising with 1mm rise in fairly flat coastlines which has resulted to 1.5m retreat of beachfronts and low laying island nations becoming inundated and aquifers overrun by sea water. This is due to increased volumes of water brought in from melting land ice and thermal expansion of the ocean waters.
Moreover, studies on global fisheries have shown changes in number, size and representativeness of fish communities. Fish have migrated to other habitats where conditions are more suitable. Finally, the view that global warming trend is as a result of ‘urban heat island effect’ does not hold any water at all. The NASA GISS center explains while compiling temperature records the effects of UHI are removed by comparing urban long term trends and nearby rural trends and the fact that temperature measurements and modeling have improved over the years. Furthermore temperature measurements also are not placed in urban ‘heat zones’ such as industrial areas or the areas with a lot of activity, rather they are placed in parks and similar places which are cooler than the rest of the city. Therefore, this argument that global warming trend is as a result of UHI is becoming more and more unpopular.
Works Cited
Blaustein, Andrew. & Dobson, Andy. “Extinction: A message from the frogs”. Nature. 2006. Web.
Bruno, John. The Encyclopedia of the Earth. Coral reefs and climate change. 2008. Web.
Harden, Blaine. “Experts predict Polar beer decline: Global warming is melting their ice pack habitat”. Washington Post. 2005. Web.
Inhofe, James. “A Skeptic’s Guide to Debunking Global warming Alarmism: Hot or Cold Media Spin cycle: A challenge to journalists who cover global warming”. Senate Floor. US Senate Washington. 2006. Speech.
“Scientific Evidence.” Woods Hole Research center.org. Woods Hole Research center. n.d. Web. 2010. Web.
Shwartz, Mark, Stanford News Service. News release: Effects of global warming already being felt on plants and animals world wide. 2003. Web.
World Wide Fund for Nature. Global Warming and the World Fisheries: Are We Putting Our Fish in Hot Water? 2008. Web.