The Main Sources Of Carbon Dioxide Emissions Environmental Sciences Essay

Since the Industrial Revolution, human activities such as the burning of oil, coal and gas, as well as deforestation have greatly increased CO2 concentrations in the atmosphere. Almost all CO2 emissions (about 96.5%) come from fossil fuels use. The 3 types of fossil fuels that are used the most are coal, natural gas and petroleum. When fossil fuels are combusted, the carbon stored in them is emitted almost entirely as CO2.

The three main sectors that use fossil fuels are:

• Transportation

• Utilities (power, gas, oil etc…)

• Industrial production

Transportation:

The first new projections of future aircraft emissions in 10 years predict that carbon dioxide and other gases from air traffic will become a significant source of global warming as they double or triple by 2050.

• The most important source of CO2 emissions worldwide is caused by the transportation of goods and people. The emissions caused by people traveling (by car, plane, train, etc…) are examples of direct emissions since people can chose where they are going and by what method.

• The emissions caused by the transportation of goods are examples of indirect emissions since the consumer has no direct control of the distance between the factory and the store. Since the distance between the manufacturer and the consumer is constantly growing, more pressure is put on the transportation industry to bridge this gap and this ends up creating more indirect emissions. What’s worse is that 99% of the energy used to transport people and goods all over the world comes from the combustion of fossil fuels.

Industrial production:

• Manufacturing and industrial processes all combine to produce large amounts of each type of greenhouse gas but specifically large amounts of CO2 because of two reasons. First, many manufacturing facilities directly use fossil fuels to create heat and steam needed at various stages of production. Second, their energy intensive activities use more electricity than any other sector so unless they are using renewable sources the energy that they use is responsible for vast amounts of emissions.

• By industrial production we are mainly talking about manufacturing, construction, mining, and agriculture. Manufacturing is the largest of the 4 and can be broken down into 5 main categories: paper, food, petroleum refineries, chemicals, and metal/mineral products. These categories account for the vast majority of the energy use and CO2 emissions by the sector.3, 4

Land-use Change

It is estimated that man-made changes in land-use have, until now, produced a cumulative global loss of carbon from the land. Widespread deforestation has been the main source of this loss, estimated to be responsible for nearly 90 percent of losses since the mid-nineteenth century. Losses primarily occur due to the relatively long-term carbon sinks of forests being replaced by agricultural land.

The conversion of land from forested to agricultural land can have a wide range of negative effects as far as greenhouse gas emission is concerned. Soil disturbance and increased rates of decomposition in converted soils can both lead to emission of carbon to the atmosphere, with increased soil erosion and leaching of soil nutrients further reducing the potential for the area to act as a sink for carbon.

Respiration

Respiration, both on land and in the sea, is a key component of the global carbon cycle. On land, an estimated 60 Pg C (60 billion tones) is emitted to the atmosphere each year by autotrophic respiration.

In the sea, autotrophic respiration is thought to account for about 58 Pg of the dissolved inorganic carbon in surface waters each year, with the contribution of heterotrophic respiration being 34 Pg C.

Effects of increasing temperatures on pollution can be observed which :

1. Higher temperatures due to carbon dioxide increased the chemical rate of ozone production in urban areas

2. Increased water vapor due to carbon dioxide-induced higher temperatures boosted chemical ozone production even more in urban areas.

Engineers have designed a simple, sustainable and natural carbon sequestration solution using algae. A team at Ohio University created a photo bioreactor that uses photosynthesis to grow algae, passing carbon dioxide over large membranes, placed vertically to save space. The carbon dioxide produced by the algae is harvested by dissolving into the surrounding water. The algae can be harvested and made into biodiesel fuel and feed for animals. A reactor with 1.25 million square meters of algae screens could be up and running by 2010.

America is by far the largest contributor to global warming than any other country — releasing a quarter of the world’s carbon dioxide — the primary cause of global warming.

Bayless, with a team at Ohio University, created a photo bioreactor that uses photosynthesis to grow algae just like a plant would take carbon dioxide up and, through the energy of the sun, convert that into oxygen.

“That passes the carbon dioxide over these membranes,” Ben Stuart, an Ohio University environmental engineer, tells DBIS. “These membranes are fabric just like your shirt. It’s a woven material, and as the carbon dioxide pass by them, that carbon dioxide dissolves into the water.”

That carbon dioxide is broken down by the algae. Nitrogen and clean oxygen are released back into the atmosphere. But to capture the CO2 created from a power plant, algae would have to fill a building the size of Wal-Mart.

“The size of these things would be enormous, about an acre worth of land space. And so the flu gases would run through this huge building and the algae would be growing on the suspended vertical surfaces.” Stuart says.

But what makes it cost effective? The algae can be harvested and made into biodiesel fuel and feed for animals.

# Sea level rise – densely settled coastal plains would become uninhabitable with just a small rise in sea level, which would result from melting of the ice caps

# Impacts on agriculture – Global warming could have major effects on agricultural productivity

# Reduction of the ozone layer – Warming would result in increase high cloud cover in winter, giving chemical reactions a platform in the atmosphere, which could result in depletion of the ozone layer

# Increased extreme weather – A warmer climate could change the weather systems of the earth, meaning there would be more droughts and floods, and more frequent and stronger storms

# Spread of diseases – Diseases would be able to spread to areas which were previously too cold for them to survive in

# Ecosystem change – As with the diseases, the range of plants and animals would change, with the net effect of most organisms moving towards the North and South Poles