Societal Effects from of Air Pollution

Destabilization of local climates

The first recorded South Atlantic hurricane, "Catarina", which hit Brazil in March 2004.

In the northern hemisphere, the southern part of the Arctic region (home to 4,000,000 people) has experienced a temperature rise 1 °C to 3 °C (1.8 °F to 5.4 °F) over the last 50 years. Canada, Alaska and Russia are experiencing initial melting of permafrost. This may disrupt ecosystems and by increasing bacterial activity in the soil lead to these areas becoming carbon sources instead of carbon sinks. A study (published in Science) of changes to eastern Siberia's permafrost suggests that it is gradually disappearing in the southern regions, leading to the loss of nearly 11 % of Siberia's nearly 11,000 lakes since 1971. At the same time, western Siberia is at the initial stage where melting permafrost is creating new lakes, which will eventually start disappearing as in the east. Western Siberia is the world's largest peat bog, and the melting of its permafrost is likely to lead to the

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release, over decades, of large quantities of methane—creating an additional source of greenhouse gas emissions.

Hurricanes were thought to be an entirely North Atlantic phenomenon. In April 2004, the first Atlantic hurricane to form south of the Equator hit Brazil with 40 m/s (144 km/h) winds; monitoring systems may have to be extended 1,600 km (1000 miles) further south.

Sea level rise

Sea level has been rising 0.2 cm/year, based on measurements of sea level rise from 23 long tide gauge records in geologically stable environments Main article: Sea level rise

With increasing average global temperature, the water in the oceans expands in volume, and additional water enters them which had previously been locked up on land in glaciers, for example, the Greenland and the Antarctic ice sheets. An increase of 1.5 to 4.5 °C is estimated to lead to an increase of 15 to 95 cm.

The sea level has risen more than 120 metres since the peak of the last ice age about 18,000 years ago. The bulk of that occurred before 6000 years ago. From 3000 years ago to the start of the 19th century, sea level was almost constant, rising at 0.1 to 0.2 mm/yr; since 1900, the level has risen at 1-2 mm/yr; since 1992, satellite altimetry from TOPEX/Poseidon indicates a rate of about 3 mm/yr

The Independent reported in December 2006 that the first island claimed by rising sea levels caused by global warming was Lohachara Island in the Sundarhans in Bay of Bengal. Lohachara was home to 10,000. Earlier reports suggested that it was permanently flooded in the 1980s due to a variety of causes, that other islands were also affected and that the population in the Sundarbans had more than tripled to over 4 million

Temperature rise

The temperature of the Antarctic Southern Ocean rose by 0.17 °C (0.31 °F) between the 1950s and the 1980s, nearly twice the rate for the world's oceans as a whole. As well as effects on ecosystems (e.g. by melting sea ice, affecting algae that grow on its underside), warming could reduce the ocean's ability to absorb CO2.

More important for the United States may be the temperature rise in the Gulf of Mexico. As hurricanes cross the warm Loop Current coining up from South America, they can gain great strength in under a day (as did Hurricane Katrina and Hurricane Rita in 2005), with water above 85 °F seemingly promoting Category 5 storms. Hurricane season ends in November as the waters cool.

Acidification

The world's oceans soak up much of the carbon dioxide produced by living organisms, either as dissolved gas, or in the skeletons of tiny marine creatures that fall to the bottom to becom e chalk or limestone. Oceans currently absorb about one metric tonne of CO2 per person per year. It is

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estimated that the oceans have absorbed around half of all CO2 generated by human act ivities s ince 1800 (120,000,000,000 tonnes or 120 petagrams of carbon).

But in water, carbon dioxide becomes a weak carbonic acid, and the increase in the greenhouse gas since the industrial revolution has already lowered the average pH (the laboratory measure of acidity) of seawater by 0.1 units on the 14-point scale, to 8.2, Predicted emissions could lower it by a further 0.5 by 2100, to a level not seen for millions of years.

There are concerns that increasjng aci dificat ion could have a particularly dejujjmental effect on corals (16% of the world's coral reefs have died from bleaching since 1998) and other marine organis ms w ith calcium carbonate shells. Increased acidity may also directly affect the growth and reproduction^ fish as well as the plankton on which they rely for food

Shutdow n of thermohaline circulation

There is some speculation that global warming could, via a shutdown or slowdown of the thermohaline circulation, trigger localized cooling in the North Atlantic and lead to cooling, or lesser warming, in that region. This would affect in particular areas like Scandinavia and Britain that are warmed by the North Atlantic drift. More significantly, it could lead to an oceanic anoxic event.

The chances of this near-term collapse of the circulation are unclear; there is some evidence for the short-term stability of the Gulf Stream and possible weakening of the North Atlantic drift. There is, however, no evidence for cooling in northern Europe or nearby seas. At this point, temprerature increases are the observations that have been directly made.

Ecosystems

Rising temperatures are beginning to have a noticeable impact on birds. Secondary evidence of global warming — lessened snow cover, rising sea levels, weather changes — provides examples of consequences of global warming that may influence not only human activities but also the ecosystems. Increasing global temperature means that ecosystems will change; some species are being forced out of their habitats (possibly to extinction) because of changing conditions, while others are flourishing.

Few of the terrestrial ecoregions on Earth could expect to be unaffected. Many of the species at risk are arctic and antarctic fauna such as polar bears, emperor penguins, many salt wetland flora and fauna species, and any species that inhabit the low land areas near the sea. Species that rely on cold weather conditions such as gyrfalcons, and snowy owls that prey on lemmings that use the cold winter to their advantage will be hit hard.

Butterflies have shifted their ranges northward by 200 km in Europe and North America. Plants lag behind, and larger animals' migration is slowed down by cities and highways. In Britain, spring butterflies are appearing an average of 6 days earlier than two decades ago. In the Arctic, the waters)

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of Hudson Bay are ice-free for three weeks longer than they were thirty years ago, affecting polar bears, which prefer to hunt on sea ice.

Two 2002 studies in Nature (vol 421) surveyed the scientific literature to find recent changes in range or seasonal behaviour by plant and animal species. Of species showing recent change, 4 out of 5 shifted their ranges towards the poles or higher altitudes, creating "refugee species". Frogs were breeding, flowers blossoming and birds migrating an average 2.3 days earlier each decade; butterflies, birds and plants moving towards the poles by 6.1 km per decade. A 2005 study concludes human activity is the cause of the temperature rise and resultant changing species behaviour, and links these effects with the predictions of climate models to provide validation for them. Grass has become established in Antarctica for the first time.

Forests in some regions potentially face an increased risk of forest fires. The 10-year average of boreal forest burned in North America, after several decades of around 10,000 km² (2.5 million acres), has increased steadily since 1970 to more than 28,000 km² (7 million acres) annually. This change may be due in part to changes in forest management practices.

Also note forest fires since 1997 in Indonesia. The fires are started to clear forest for agriculture. These occur from time to time and can set fire to the large peat bogs in that region. The CO? released by these peat bog fires has been estimated, in an average year, to release 15% of the quantity of CO2 produced by fossil fuel combustion.

Ecological productivity

Increasing average temperature and carbon dioxide may have the effect of improving ecosystems' productivity. Aymospheric carbon dioxide is rare in comparison to oxygen (less than

1 % of air compared to 21 % of air). This carbon dioxide starvation becomes apparent in photorespiration. where there is so little carbon dioxide, that oxygen can enter a plant's chloroplasts and takes the place where carbon dioxide normally would be in the Calvin Cycle. This causes the sugars being made to be destroyed, badly suppressing growth. Satellite data shows that the productivity of the northern hemisphere has increased since 1982 (although attribution of this increase to a specific cause is difficult).

IPCC models predict that higher CO2 concentrations would only spur growth of flora up to a point, because in many regions the limiting factors are water or nutrients, not temperature or CO2; after that, greenhouse effects and warming would continue but there would be no compensatory increase in growth.

Research done by the Swiss Canopy Crane Project suggests that slow-growing trees only are stimulated in growth for a short period under higher CO2 levels, while faster growing plants like liana benefit in the long term. In general, but especially in rain forests, this means that liana become the

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prevalent species; and because they decompose much faster than trees their carbon content is more quickly returned to the atmosphere. Slow growing trees incorporate atmospheric carbon for decades.

Unit 2 Vocabulary

anoxis	[qn'OksIs]	KHCJiopoflHoe ronoaaHHe	KHCHeBe rojioayBaHHa
carbon sink	fkRbqn sINk]	nornoTHTe^L ymepo/ia	norjiHHai Byrjiemo
deforestation	[dlfOrO'stelSn]	BtipySKa Jieca	B«py6Ka Jiicy
desertification	["dFzqtlflkelSn]	onycnjHHBaHHe	3nycTHHeHiw
dimming	['dlmlN]	noTeMHenHe	nOTCMHIHHfl
gyr falcon	[GWfxIkqn]	KpeieT	KpeneT
lemming	['IFmIN]	jieMMHHr	JieMlHF
peat bog	[pJt bOg]	TOp4)flHOe 6OJIOTO	TOp(J)'HHe 6OHOTO
permafrost	['pWmqfrOst]	BeHHaa Mep3JioTa	BiiHa Mep3JiOTa
refuge	rrFfjHG]	ySeiKHiqe	npHTyjiOK, cxoBaHKa
shutdown	[•SAtdaun]	OCTaHOBKa, BblKJKO^ieHHe	3>TIHHKa, BHMHKaHHJI
spur	[spW]	no6y>KnaTB	cnOHyKaTH
starvation	[stRVelSqn]	roJiojiaHne	rononysaiiHsi
thermohaline circulation	['TWmqhqlaln sWkju'lelSqn]	TepMH^ecKaa liupKyiuman	TepMiMHa uHpKyjiama
trigger	f'trlgq]	BbntiBaTh, npoBouHpoBaTb	BH3HBaTH, npOBOKyBaTH
validation	[vq'IldelSn]	no^TBepayieHHe	niaTBepflHceHHJi
vulnerability	[vAJnqrq'bllltl]	VJBBHMOCTb	Bpa3^HBlCTb

Questions for discussion:

1. What's the main reason of evaporation rates reducing?

2. What's the effect of melting of permafrost melting?

3. How has sea level been rising?

4. What could be the effect of warming an ocean?

5. How may increased acidy affect the growth and reproduction offish?

6. How does warming influence birds?

7. What species are at risk now?

8. What are the recent changes in behavior by plant and animal species?

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Unit 3 Pollution and Society

Pollution in our world effects two essential aspects of our planet: air and water. Although their pollutants are emitted in completely different ways, they both harm living organisms. Air pollution is predominately emitted though the exhaust of motor vehicles and the combustion of fossil fuels, whereas water pollution is the result of industrial waste and environmental accidents. Our society knows that pollution is harmful and a serious problem for Earth but generally people don't care. Nevertheless everybody needs to contribute to prevention and pay attention to government control in the amount of material large industries can emit into the air and/or water. Industry gives off a good share of the waste that is polluting our planet, but it's every person is contributes as well. Government involvement is key to regulating toxins, building waste systems and protecting air and waters. The earth's atmosphere is composed primarily of nitrogen, oxygen, argon and carbon dioxide (the major components) as well as neon, krypton, helium and methane (the most predominate of the minor components) it is these gases which make up the 5.6* 10¹⁵ ton "shell" that surrounds our planet. However, humans, animals and vegetation in the Unites States alone emit 264 million tons of substances into the atmosphere each year. On a worldwide scale that turns out to be approximately 6.6 billion tons. These substances, which aren't naturally part of the atmosphere, are called pollutants. Over ninety percent of all air pollutants can be divided up into five categories: carbon monoxide, nitrogen oxides, hydrocarbons, sulfur oxides and suspended particulate matter. Mass is only one way of categorizing pollutants. Substances can also be looked at from an effect stand point. For example, carbon monoxide (CO) comprises 56% of all air pollutants when looked at in terms of total mass. However, when looked at in terms of effect, CO makes up only 2.5% of the pollutants. In contrast, hydrocarbons make up 13% of all pollutants when look at in terms of mass but that number jumps to 71.5% when looked at from an effect point of view.

Carbon Monoxide (CO) is a colorless, odorless, tasteless gas and is the most abundant and widely distributed air pollutant. Even though vast quantities of carbon monoxide enter the atmosphere each year (147 million tons in the US alone) the majority of the emissions are due to natural causes instead of anthropogenic, human causes. It is because of this that carbon monoxide is viewed as the least danger to living beings. The largest natural cause of CO is the oxidation of methane in the atmosphere. Methane, CH4, is produced on the surface of earth by the decay of organic matter. It then rises into the atmosphere in a gaseous state, and oxidizes to form methyl radicals (CH3) which react further to ultimately produce CO.

CH44OH-H2CHCH3 CH4-fOOH-t€H₃

A smaller natural cause is the growth and decay of chlorophyll which is the green pigment in the leaves of plants. Eighty percent of the carbon monoxide that is emitted by humans is by

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transportation (mostly by gasoline powered vehicles). Because automobiles are the largest source of CO pollution, the highest concentration of this gas is in highly populated/urban areas. The next greates t anthropogenic sou rcejs agjjcultural_burning, which accounts for another twelve percent. It has been shown mat^x^ojui^^o^gh__c^ncentrations_of carbon monoxide can harm living organisms, but the current co ncentra tion in our atmosphere is still low enough so that plants and humans are both at minimal risk.

The category of Nitrogen Oxides is made up primarily of three different gases; nitrogen dioxide (NO2), nitrous oxide (N2O), and nitric oxide, NO. Nitrous oxide is over four times more toxic than nitric oxide. Nitrogen dioxide is generally not considered a pollutant because it is not toxic and usually not produced by humans. On the basis of mass, the nitrogen oxides make up the smallest group of pollutants and have the second smallest effect on life, behind CO. As with carbon monoxide, nature emits greater amounts of these gases than humans do. The leading natural causes include the decomposition of soil, bacterial activity and lightning. Anthropogenic emissions are mostly due to the combustion of fuel. Natural air is composed of 78% nitrogen and 21% oxygen, which don't react at normal temperatures, but can react if the temperature is hot enough (1300-2500° C). In these cases, the quantity of nitrogen oxides released varies depending on the temperature and the ratio of nitrogen ^ oxygen. The increasing use of nitrogenous fertilizers is among the reasons that emissions of N2O have been on the rise. Damage to plants by N2O has only been observed near nitric acid facilities and no evidence of NO damage has ever been seen outside the laboratory. It was concluded that the level of concentration of these gases is too low to cause significant problems at this time.

The category of Sulfur Oxides mostly consists of sulfur dioxide, SO2. Sulfur trioxide, SO3J does exist but it doesn't stay in our atmosphere. Sulfur trioxide is very reactant with moisture (H2O) and forms sulfuric acid, H2SO4, one of the substances in acid rain. Unlike the two prior groups, the sulfur oxides are predominately emitted by humans. However, a fair amount of SO2 is produced in the atmosphere. Hydrogen Sulfide, H2S, is produced by the decay of organic matter, and then rises to the atmosphere where it oxidizes and forms sulfur dioxide.

Around 80% of the sulfur oxides emitted by humans are due to the combustion of coal. Coal, which is formed from once-living organisms, contains some sulfiu^When this combusts (fire results when a substance reacts with oxygen) sulfur oxides are formed. Although sulfur is an element necessary for life, too much or too little sulfur can harm organisms. The effect of sulfur oxides on plants varies with time of exposure and concentration. In general, too much exposure, either a short time with a high concentration or a long time with a low concentration, results in damage to the leaves. Unlike the two prior categories, the present level of sulfur oxides actually effects humans, generally through the respiratory system. In most cases the amount inhaled is not enough to give

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any serious results besides coughing, but if vast quantities are inhaled into the lungs it is possible to get a respiratory infection.

Hydrocarbons are the second largest category of air pollutants by mass, but they are by far the largest group of pollutants when considering their effect. There are thousands of different hydrocarbon compoundsjhat are comprised solely of hydrogen and carbon. They can be found in a gaseous, liquid or solid states at room temperature. Most hydrocarbons are emitted by the bacterial

decomposition of organic material. Methane, CH4, which was mentioned in the formation of carbon monoxide, is the simplest of the hydrocarbons. Petroleum is a complicated mixture of several simple hydrocarbons showing again transportation by motor vehicles is the leading cause of this category being emitted into the air. Their evaporation during the_refining_of petroleum is also important. Unlike the previous categories, the hydrocarbons are relatively harmless in their released state. It is in the atmosphere that they undergo chemical reactions and become hazardous. With this change the primary pollutants (substances within the five original categories) become secondary pollutants (new resultant substances). O+O2=O3

These secondary pollutants, ozone (03,) and peroxyacetyl nitrate (PAN), are known to cause damage to plants, especially citrus trees, salad crops and coniferous trees. However, even though hydrocarbons are extremely dangerous to plants, studies have revealed no direct effects on humans at the current level of concentration. As a matter of fact, the concentration would have to be a hundred to a thousand times larger in order to see any direct effects.

The final category of pollutants is the suspended particulate matter, or particuiates for short. Unlike the other four categories particuiates are not gases, they are small solid or liquid particles such as smoke, mist, or dust that measure between.0002| m to 5000 m (m being a micrometer or one millionth, 10"⁶ meters). Particuiates are formed in two ways, the clumping together of microscopic fragments or the breaking up of larger particles. Nature emits particuiates in a variety of ways. Similar to hydrocarbons, various gases react in the atmosphere and form particuiates. Blowing dust can be categorized as particuiates, but the largest natural cause of particles is the bursting o f tiny air bubbles at the surface of the ocean that results in the release of microscopic salt particles into the air. Unlike the previous categories, humans emit minimal quantities of particuiates by transportation; fires, incomplete combustion of fossil fuels, and industrial breaking of stone, give off most human released particuiates. Few studies have been conducted to see the effect of particuiates on plants, but it has been found that when dust settles on their leaves sunlight is partially blocked, thus preventing growth of the plant. The effect on humans is entirely in the respiratory system. Small particles (those less than 5 m) can get by the defenses of the upper respiratory system and reach the lungs; the smaller the particle, the deeper into the lungs it can get and the more problems it can cause, because they become increasingly difficult for the body to remove.

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Societal Effects from of Air Pollution

People are mostly oblivious to the effects of air pollution. They know it's out there and it is a problem but excepting skin cancer, there have been very few deaths with a direct link to air pollution. It is probably because of this that people aren't as^concerned_with air pollution as they should be. Air pollution has always been around, and has actually been on a decline since the I960's (when coal was the major source of energy.) It is relativelyeasy. to decrease the amount of pollutants we emit (each year ncwjaws arise that crack down on the amount of certain substances that can be released into the air) but the harm has already been done, and next to Impossible to fix. The ozone layer is the part of the atmosphere that keep s ultr a viole t rays from penetrating humans and plants. But because of all the air pollution, various chemicals are slowly destroying the ozone layer. Each year the concentration of the ozone decreases by approximately two percent and the ozone layer over t he So uth Pole is already fifty percent of its natural concentration. Ozone depleters (the majority of which are chlorofluorocarbons or CFC's) react with ultraviolet radiation and break down into their component atoms, especially chlorine, bromine and fluoride. These component atoms then go on to steal an oxygen atom from the ozone layer (opposite to the reaction which forms O3), thereby destroying, the ozone layer. This loss of protection from UV rays can result in an increase of human skin cancer, damage to various parts of the eyes as well as causing a breakdown of the immune system. With health being such a major issue in our society today, people have become scared by this "outbreak" of cancer. People know that the ozone layer is slowing depleting and that there is a^health_risk_involved with being in the sun for extended periods of time. But very few people know that there is a connection between this breakdown of the ozone layer and air pollution. Instead of trying to control pollution emissions they just cut back on their time outdoors, or wear more sunscreen. Ultraviolet rays can also cause major environmental problems. These rays enter the atmosphere and can kill small aquatic organisms, such as plankton. When these small life forms decompose they release carbon dioxide, CO2, another gas which can cause the ozone layer to break down, thus resulting in a continuous cycle.

Another danger of air pollutants is before they get high enough in the atmosphere to break down the ozone layer, they are the leading cause of the greenhouse effect. These chemicals reflect some of the earth's heat back down to earth, raising the surface temperature. The rise in temperature is known as the greenhouse effect. If this rise in temperature continues it could start to melt the polar icebergs, which would result in the oceans rising and in turn flooded coastal areas. This is one of the few effects of pollution that our society is actively worried about. The subject of the greenhouse effect is highly publicized and therefore people know about the risks concerning this topic. Even though people know about the greenhouse effect, they fail, once again, to see the why behind this event. People believe that the greenhouse effect is due to the ozone layer breaking down

and in turn more ultraviolet rays enter our atmosphere which is the reason the temperature is increasing. Although this belief isn't entirely accurate it is close enough for our purposes. As in the case with the problems of the ozone layer, society fails to see that this is all a result of air pollution. Although air pollution has relatively few immed iate effec tson humans at the present time it is important that we try to reduce the amount of pollutants we emit into the air. As discussed before the biggest cause of air pollution is use of transportation, followed by the combustion of fossil fuels. In the past thirty years many new standards have been passed in the United States which resulted in a dramatic reduction in the gases emitted by automobiles (such as the Clean Air Act of 1979). But even with these new laws air pollution is still on the increase. It is mostly due to the fact that there are more automobiles on the road today. Cars may be more efficient but there are too many of them, which in many ways diminishes their effici ency. One solution to this problem is^ncouraging people to carpool which would reduce the number of cars on the road and in turn reduce the amount of pollutants. Another solution is to make more laws enforcing more_efficient cars. However this would cost^carjnanufactures more money, resulting in more expensive cars which people wouldn't want to buy. So the best solution to reducing the amount of pollutants emitted by automobiles is by encouraging people to carpool.

The combustion of fossi l fuels is the otherjeading cause of air pollution. Although the amount of pollutants these factories emit has reduced since the 1950's (when poal was the primary source of energy) they stifl release a Jarge quantity of dangerous gases. More standards can be enforced to reduce the emissions of these factories. Nevertheless, as long as we rely on fossil fuels for energy these factories will have to emit some sort of gas. At the moment, nuclear energy appears to be the wave of the future and this type of energy releases a lot less pollutants into the air than the combustion of oil and coal. Although air pollution presents no immediate danger it is important that we try to control the pollutants we emit. Most of the harm has already been done and there are no known ways to fix these problems. It is for this reason that we try our best to help the situation as most as possible.

Questions for Review

1. What's the composition of Earth? ajfttfJtfaX ■

2. What causes 80% of carbon monoxide that is emitted by humans?

3. Where is the highest concentration of cp?

4. How do sulfur oxides actually effect humans?

5. What's petroleum?

6. In what way does the Ozon layer save our planet?

7. What is the greenhouse effect?

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