Chapter One
Introduction
1.1 Background to the study

The fingerprint of human activity has been detected in the recently observed warming on global and continental scales (Christidis et al 2011: 1922). This was also confirmed by Riebeek (2007:1) when he said that scientists have evidenced that humans are to be blamed for the global warming that is happening now due to the fact that for decades cars and factories have spewed billions of tons of greenhouse gases into the atmosphere and these gases tend to make temperature to rise. Global warming is defined as the increase of the average temperature on earth. According to Smitha 2011: 1923), the buildup of carbon dioxide in the atmosphere mainly from fossil fuel emissions, is the most significant human cause of global warming. Carbon dioxide is released everytime people burn things like car, airplane, or coal plant. This means people should burn less fossil fuel.

Also, deforestation increases the severity of global warming. Carbon dioxide is released from the human conversion of forests and grasslands into farmland and cities. All living plants store carbon dioxide. When those plants die and decay, it is released back into the atmosphere. Although global warming is scientifically accepted, its cause is still disputed. Nordell (2003) suggested a most natural explanation; that this warming is a result of heat emissions from the global consumption of non-renewable energy.

1.2 Statement of the problem

Global warming is putting pressure on ecosystems, the plants and animals that co-exist in a particular climate. According to Riebeek (2007: 14), global warming will impact life on earth in many ways, but the extent of the change is up to us. Scientists have shown that human emissions of greenhouses gases are pushing global temperatures up, and many aspects of climate are responding to the warming in the way that scientists predicted they would. Ecosystems across the globe are already affected and surprising changes have already taken place since greenhouse gases are long-lived, the planet will continue to warm and changes will continue to warm and changes will continue to happen, but the degree to which global warming changes life on earth depends on our decisions. Also, the IPCC reports that both heat waves and intense rain events have increased in frequency during the last 50years, and human-induced global warming more likely than not contributed to the trend.

It is against this background that this study intends to take an indepth study of the activities of human on global warming. This study is a great contribution to the literature as other authors have focused on the causes and effects of global warming, even though some authors have written on human causes of global warming, only few have focuses on assessment of human activities on global warming. This is the gap this study intends to fill in the literature.

1.3 Objective of the study

The main objective of this study is to assess the impact of human activities on global warming. In order to achieve this objective, the following are the specific objectives:

1.) To trace the history of global warming and also examine the causes of global warming

2.) To understand how human activities have triggered global warming.

1.4 Research Questions

1.) What is the meaning of global warming?

2.) What are the factors that can lead to global warming?

3.) How has human activities caused global warming?

1.5 Research Hypothesis

1.) Human activities do not lead to global warming

2.) Human activities lead to global warming.

1.6 Significance of the study

This study is very significant for its timely nature. It will help policy makers to make policies that would minimize the way human activities cause climate change hence leading to global warming. It will help humans to put a check on how their activities affect the environment. This will also help student researchers that want to look into the effect of human activities on global warming and the policies and recommendations will further assist the government and make the environment sustainable.

1.7 Scope of the study

This study covers the factors that are responsible for global warming with particular focus on how human activities to global warming. The various activities carried out by humans will be examined and the various effects on their global system will be analyzed.

1.8 Limitation of the study

This study is limited in terms of gathering information as regards the human activities. Due to the peculiarity of this topic, there was constraint in terms of finding the relevant materials.

1.9 Definition of terms

1.) Global warming: this means the heat has been accumulating in air, water, and ground. It is the increase in average temperature of the earth (Venkataramanan and Smitha 2011: 226).

2.) Greenhouse gases: this refers to the gases that contribute to the greenhouse effect. The major greenhouse gases include watervapour, carbon dioxide, methane, and ozone. Other greenhouse gases include but not limited to nitriousoxide, chlorofocarbon, etc. The largest contributing source of greenhouse gas is the burning of fossil fuels leading to the emission of carbon dioxide.

3.) Greenhouse effect: this refers to a situation of reflecting back the heat energy by the atmosphere.

4.) Deforestation: this refers to the cutting down of trees by humans. It is known as one of the human causes of global warming.

References

1.) Riebeek, H. (2007), “Global Warming”, Earth Observatory, 1-15.

2.) Venkataramanan, M. and Smitha (2011), “Causes and Effects of Global Warming”, Indian Journal of Science and Technology, 4(3): 226-229.

3.) Christidis, N., Stott, P. and Brown, S. (2011), “The Role of Human Activity in the recent warming of extremely warm daytime temperatures”, Journal of Climate volume 24: 1922-1930.