Global Warming "The warnings about global warming have been extremely clear for a long time. We are facing a global climate crisis. It is deepening. We are entering a period of consequences." -Al Gore Team 10 By: Kharthik, Meraz, Parmeet, Teji, Viven and Garav
Introduction Global warming has been a problem for many years now and it is worsening each and every day. There are many causes to this problem and various solutions have been made; but these solutions mean nothing if they are not implemented by the world society. If we continue to live on as we do now, the world soon may end up looking like this.
Causes of Global Warming • Mining and emission of fossil fuels • Gasoline • Coal • Several heat-trapping gases • Carbon Dioxide • Nitrous Oxide • Methane • Chlorofluorocarbons • Deforestation
Fossil Fuels • Industrial Revolution in late 18th century marked beginning of combustion of fossil fuels for energy • When these fossil fuels are burned they release a gas called carbon dioxide • The process is called internal combustion • By 1990 the Earth's atmosphere had 25 times more CO2 in the atmosphere
How Greenhouse Gases Lead To Global Warming 1) Solar radiation from the sun makes it's way down to earth in the form of visible light. 2) The majority of the radiation is absorbed by the Earths surface. 3) However some radiation is reflected by the earth and the atmosphere4) some of the infrared radiation passes through the atmosphere, and some is absorbed and re-emitted in all directions by greenhouse gas molecules. As a result, earth's surface and lower atmosphere warm up significantly (global warming).
Greenhouse Gases of the Atmosphere • Carbon Dioxide (CO2) • Nitrous Oxide (N2O) • Methane (CH4) • Chlorofluorocarbons (CFC's)
CO2 in the Atmosphere • Produced by many internal combustion engine locomotives • Cars • Trains • Airplanes • Ships • CO2 in the atmosphere acts as a blanket • When the CO2 in the atmosphere thickens it traps more heat • When more heat is trapped, the Earth becomes warmer
Nitrous Oxide Emissions • Causes of Nitrous Oxide emissions include: • Soil Management In Agriculture • Synthetic fertilizers • Production of Nitric Acid • By-product in the process of making Nitric Acid • Human sewage • N2O may be generated during nitrification and dinitrification • Manure management of livestock • Decomposition of nitrogen in organic manure • Mobile & stationary sources of fossil fuel combustion • Emitted in all automotive vehicles • Humans are responsible for 96% of N2O emissions
Methane Emissions • Methane (CH4) is known to be another significant greenhouse gas • Concentration of methane has doubled since the last 200 years • The gas is produced through relatively unavoidable causes • Organic compounds caught in waterlogged soils • Rice • Paddy fields • Rotting waste beneath soil • Landfills • Cattle farming due to the digestion
Chlorofluorocarbons (CFC's) • Modern day uses include: • Chemicals used to propel the air from aerosol cans • Cooling agent for refrigerators and air conditioners • Became popular in the industry since the 1970s • 10,000 times more effective than carbon dioxide at trapping heat • Play a role in depleting the ozone layer
Deforestation • Rain forests are important because: • They hold half the animal species in the world • 90,000 of 250,000 known botany derive from the rain forests • Have great biodiversity & represent 60 million years of biodiversity • One in four chemists will have chemical compounds derived from the rain forest • Botany of rain forests provide for many medicines such as antibiotics • 3,000 plants have anti-cancer properties in which 70 per cent are grown in the rain forest • By-products of tropical forests include essentials such as oils, latex and gum • Only 7 per cent of global landmass is the rain forest
Why is deforestation relevant? • Trees are carbon banks • Trees absorb CO2 and release O2 • 6CO2 + 6H2O C6H12O6 + 6O2 • Therefore, through the process of photosynthesis, glucose and oxygen gas are the reagents of CO2 and H2O • Not only do trees remove CO2 but they produce O2 in order for life to be sustainable
Greenhouse Effect • Green house effect is introduced by trapping by gases in the atmosphere of radiation emitted by earth • Energy from the sun warms the Earth, therefore sustaining life on earth
What happens to radiation that sum emits? • Amount of energy radiated by a body depends on its surface area A, absolute temperature T and the properties of the surface: P = eδAT4 δ = Stefan-Boltzmann constant and equals 5.67 * 10^-8 Wm^-2K^-4 e is the emissivity of the surface (varies from 0 – 1)
Black Body • The special case from the equation P = eδAT4, where the emissivity surface e is 1 is known as black body • Black body represents a perfect emitter • Darker Surfaces have values of e closer to 1 The Sum maybe considered as a perfect emitter.
General Phenomena • Black surfaces, absorb better than light surface • We wear dark colored clothes in the winter to absorb radiation from the sun • Light surfaces are good reflectors • We wear light coloured clothes in the summer
Albedo • Ratio of the power of radiation reflected or scattered from the body to the total power incident on the body • Snow has a high albedo (0.85) meaning that snow reflects most of the suns radiation whereas charcoal has a low albedo (0.04 meaning that it absorbs most of the suns radiation • Average albedo for earth is o.3 (depends on the surface) Energy Balance • Earth has constant temperature and behaves as black body • Energy input into earth must equal energy output by the earth
The Greenhouse Effect • Solar radiation reaching earth is mainly radiation in visible spectrum • 30% of this radiation is reflected back into space • Rest arrives at earth’s atmosphere and surface • Warm them both • Earth’s surface radiates back as all warm bodies do
The Greenhouse Effect (cont'd) • Infrared radiation is strongly absorbed by various gases in the atmosphere • These are called Greenhouse gases • This radiation is reradiated by the gases in all directions • This means that some of this goes back to the earth’s surface, making it even warmer • If it weren’t for the greenhouse gases, all radiation would go back into space and earth would have temperatures 32K less than now
Absorbed ir radiation reradiated back to earth incoming Radiated back into space reflected Earth
Sources of Greenhouse Gases • Water Vapor • Evaporation • Carbon Dioxide • Forest fires, volcanic eruptions • Methane • Wetlands, oceans, lakes and rivers • Nitrous Oxide • Forest, ocean, soil and grassland
Anthropogenic Sources of Greenhouse Gases • Water Vapour • None • Carbon Dioxide • Burning fossil fuels in power plants and cars • Methane • Flooded rice fields, farm animals, termites, processing of coal, natural gas and oil, and burning biomass • Nitrous Oxide • Burning fossil fuel, manufacturing cement, fertilizers, deforestation
Sinks • Greenhouse effect is a natural consequence • More warming can harm the earth • Increase in gas quantities are due to human activities • Planting trees can absorb the carbon dioxide in the atmosphere • Methane is destroyed in the lower atmosphere by chemical reactions involving hydroxyl radicals • Nitrous oxide is destroyed by photochemical reactions
Surface Heat Capacity • Energy required to increase the temperature of 1 meter squared of the surface by 1 K • Amount of thermal energy is given by • Q = ACsT • Where A is the area • Cs is the surface heat capacity • T is the increase in its temperature Increase in concentration of greenhouse gases leads to global warming.
Effects of Global Warming 1) Diseases are spread. 2) Disruption of the ecosystems. 3) Water temperature increases. 4) Increased chances of droughts and heat waves. 5) Economic downturn. 6) The polar ice caps melt. 7) Changes in biodiversity.
Spread of Diseases • Malaria has spread among Peru • 40 years ago malaria was eradicated from Peru; but now, due to global warming and deforestation, the disease has spread with more than 64,000 cases • The unseasonal rain leaves puddles containing larvae • Logging and deforestation also cause mosquitoes and larvae to spread because the trees which house these insects are cut down then the logs are moved to other areas in which the disease is taken along with it, therefore affecting that area as well • This way, the disease is slowly and unexpectedly spread by us humans alone
Mosquitoes possibly carrying diseases such as the Dengue Fever, Malaria and the West Nile Virus.
Disruption of the Ecosystems Due to the rise in temperatures: • Species of plants and animals are becoming extinct due to the water wiping out their habitat and food source • The Adélie penguins in Antarctica have decreased in breeding pairs from 32,000 to 11,000 in the past 30 years • Polar bears have less ice to fish and live on, they are therefore decreasing drastically in numbers • Species are increasing in numbers • In Alaska, spruce bark beetles have increased in number over the past 20 years and in turn, they've eaten up 4 million acres of spruce trees
Sea Level • Sea level is always varying • Climate change affects sea level • Changes in sea level affect the amount of water that can evaporate and amount of thermal energy that can be exchanged with the atmosphere • Temperature of the earth’s surface affects the sea level
Water Temperature Increases • As ocean water temperature increases, so does the number of natural disasters (hurricanes, tsunamis) • We've seen this happen in the past decade when: • Hurricane Ivan struck in Florida in 2004 producing a stunning 117 tornadoes over three days • Indonesia was also struck by a tsunami later on in 2004, produced by a massive 9.1 magnitude earthquake • Hurricane Katrina wreaked havoc in 2005 when it struck along the Gulf Coast • These natural disasters due to global warming have become and soon will be known as global disasters
Temperature Pattern Pattern is similar to Carbon pattern
Increased Chances of Drought and Heat Waves • Although many areas of the world will be suffering from floods due to global warming, others such as Western USA, Middle East, Central Asia, Australia, Africa will be suffering from a scarcity of water and massive heat waves • The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report claims droughts have been more prominent in the past 25 years • Irrigation water in California is expected to dry up leaving 60,000 people unemployed and 1 million acres of farmland unused
Economic Downturn • Due to the increase in many natural disasters such as hurricanes, earthquakes and tsunamis, there will also be a huge increase in the money spent to redevelop the affected areas • Also, as more diseases spread throughout nations, they will need more money to treat the infected people as well as finding a cure and stop the diseases from becoming a pandemic • Furthermore, droughts are a huge economic blow to farmers • In California, the Central Valley produces over half of the US' fruits, vegetables and nuts. Due to the drought, the number one farming area in the nation is drying up, which could cause a deficit of over $36 billion per year.
Melting of Ice • Temperature is higher, then ice will melt • Land ice melting will cause sea level increase • Sea ice melting will not cause sea level increase • Lands could be filled with water, if the sea level is too high (especially coastal areas)
Polar Ice Caps Melt • If global warming continues at its alarming rate, the polar ice caps will continue to melt • By the end of the century, they are expected to rise between 7 and 23 inches and if the poles continued to melt, it could add 4-8 inches • National Snow and Ice Data Center declared if all the ice caps, glaciers and snow (5,773,000 cubic miles of water) melted today, the sea level would rise by 230 feet • By the ice caps melting, all the fresh water entering the oceans would desalinate the water which would ruin the global ecosystem, ocean currents and global temperatures • Moreover, as temperatures rise, the geography of the land will change causing endangerment to many species of animals in which only the adaptable will survive
Polar Bear stranded on a small piece of a glacier. This shows us as their habitat melts away, slowly ours will too.
Polar Ice Caps Melt (continued) • Due to the ice caps melting, there is less area for the sun to reflect light off back into space - cooling the Earth further. But, as the ice caps decrease in size, the sun rays will be forced to hit the dark ocean which would instead trap the heat and warm the Earth instead. • In Peru, the Quelccaya ice cap (containing fresh drinking water) will be gone by 2100 if it continue to melt at its current rate. This will leave thousands of people without water and electricity.
Glacier in Patagonia, Argentina 1928 (top). Glacier in Patagonia, Argentina 2004 (bottom). 76 years of climate change.
Biodiversity • Biological diversity is the variety of life on Earth and is commonly referred to as biodiversity. • The numerous species of plants, animals, and the vast diversity of genes in these species along with the many different ecosystems are all part of our Earth's biodiversity.
The Importance of Biodiversity Biodiversity boosts ecosystem productivity -all species have an important role • more plant species means more variety of crops • natural barriers against natural disasters • resistance against invasive species • pollination of plants • regulation of climate • nutrient and water recycling • pollution control