Microphone Climate Change Over the last several years there has been a heated debate in both the political and scientific arenas regarding the validity and nature of climate change. This paper will discuss several factors that lead to natural climate change as well as factors contributing to anthropogenic climate change, discuss the implications of global warming, and discuss policies that can help reduce it.

There are several processes that contribute to natural climate change (Seinfeld & Pandis, 2012):

The sun. Of course the sun is the most prominent natural climate influence. Variations in solar activity such as sunspots, changes in the solar magnetic field, etc. all have the potential to produce variations in climate.

Interactions between the atmosphere and oceans. The oceans interact with the atmosphere in several different ways including absorbing half of the key transferred to the polls, being the single most important carbon dioxide sink, etc. However, high human emission rates of carbon dioxide tax the ocean's ability to maintain equilibrium between the carbon dioxide in the atmosphere and that which is absorbed in the oceans.

3. Atmosphere -- surface interactions. There are many complicated interactions between the surface of the Earth and the atmosphere such as areas of surface that are directly exposed to the sun vs. those covered by leafy trees. Carbon can be absorbed in vegetation, higher latitudes and the cooler, etc.

4. Influence of volcanoes. Injecting vast amounts of sulfur and other dust particles in the atmosphere can absorb sunlight, reduced solar radiation, etc. resulting in cooling.

Anthropogenic influences on climate change include (Seinfeld & Pandis, 2012).

1. Albedo. Changes in the land use have affected the amount of sunlight reflected from the ground. About half of these changes have been attributed to occurring after the industrial significant amounts of reflected light have been decreased leading to a cooling effect in some areas such as higher latitudes.

2. Shifting populations. People have inhabited vulnerable locations (e.g. seashore locations, high mountainous areas, floodplains, etc.) and as such it is postulated that extreme weather events are on the rise due to these populated areas not being able to exert their balancing influence on the climate.

3. Greenhouse gases. The activities of people across the globe results in the emissions of four important greenhouse gases (carbon dioxide, nitrous oxide, methane, and halocarbons). These gases destroy the ozone layer, affect the absorption of carbon dioxide, and produce other effects that lead to climate change.

Is Global Warming Taking Place?

Yes, there is evidence for a significant increase in overall global warming (and for climate change in general) since the industrial revolution. Global surface temperatures have increased by a proximately .74°C between 1906 and 2005 (Seinfeld & Pandis, 2012). Global warming skeptics point out that the trend is not steady; however, 11 of the last 12 warmest years of occurred between 1995 and 2006 and the trend has been greater over land than over the oceans (Seinfeld & Pandis, 2012). There are several reasons to believe that this trend is not entirely due to natural causes:

1. Radiative forcing (Flanner, Shell, Barlage, et al., 2011). This is a measure of how the energy balance of the Earth's atmosphere system is influenced with other things that affect climate are changed. It is measured as the rate of energy change per unit area of the globe measured at the top of the atmosphere. When radiative forcing is positive the overall temperatures will be warmer; negative. The radiative forcing effect since the industrial era has called the largest overall positive effect which is understood to be due to human activities (e.g., increases in carbon dioxide). Estimates indicate that fossil fuel combustion is responsible for more than three quarters of human caused carbon dioxide emissions and land-use change is primarily responsible for the rest (primarily through deforestation).

2. Extreme weather changes are often caused by several factors and wide ranges of extreme temperatures across the globe are normal even in a stable climate. Nonetheless, climate researchers have concluded that changes in the likelihood of extreme temperature events such as heat waves have been linked to greenhouse warming, whereas the likelihood of cooler changes has decreased since the industrial era (Booth, 2010). Thus, while these associations are correlational in nature probability models generated from the data indicate that the best probability that these changes are due to anthropogenic factors is higher than any other explanation.

3. It is very unlikely that natural causes are responsible for the warming trend in the 20th century. For instance, paleoclimatic reconstruction models have indicated that the warming trend in the second half of the 20th century was the warmest period in the last...

This warming trend is consistent with probability models in the scientific viewpoint of how the Earth's climate should respond to rapid increases in greenhouse gases that have occurred over the last hundred years. When estimation models include the effects of greenhouse gases as well as natural factors that contribute to warming the models significantly conform to the pattern of changes observed over the last hundred years.
Can We Change the Trend?

Most climate researchers think that specific changes can affect the trend of global warming (Booth, 2010; Seinfeld & Pandis, 2012). For example, one set of technologies that can greatly reduced carbon dioxide emissions is carbon dioxide capture and sequestration. This would require large industrial: gas-fired power plants to reduce their carbon dioxide emissions by capturing carbon dioxide directly, transporting the captured carbon dioxide (typically in pipelines), and using geographic sequestration and underground and ejection into deep rock formations more than a mile below the surface that can hold the carbon dioxide (Lal, 2004). While there is some minor disagreement as to how effective such techniques would be, for the most part these techniques are considered to be a viable method of reducing carbon dioxide emissions and stabilizing anthropogenic climate change (Lal, 2004).

The cost of such a program was estimated at 2008 dollar levels of an increase in 10¢/kWh for implementing this program and new factories and even higher for factories that don't use this technology (Al-Juaied & Whitmore, 2009). The government would need to provide financial incentives for industries to implement this technology and also to reform the energy market such that investments in low carbon generations are consistent with the goals of corporations. The first phase would be to develop first -- of -- a -- kind projects with government incentives in place. These incentives should make these projects competitive with traditional industry. The next phase would be to offer incentives to existing corporations to develop and implement such technologies to their existing facilities. Again, these incentives would make this process attractive to establish corporations. Finally, it is important to let policies that make corporations who use this technology competitive with traditional industry (and even make them financially more attractive). Since the corporate mindset is to increase stock prices and profitability it is important to make these technologies attractive (Al-Juaied & Whitmore, 2009).

Another focus in the battle against global warming is the use of renewable energy sources. Renewable energy involves the use of sunlight, wind, etc. In order to develop energy sources that are replenished constantly. Low -- carbon renewable energy sources can realistically be used in power generation, the heating of water or small spaces, and as a fuel source (Panwar, Kaushik, & Kothari, 2011). The advantages of using renewable clean energy sources over traditional sources are quite obvious. However, there has been some skepticism regarding the feasibility of using these sources. However, some countries already use renewable energy and this accounts for up to 20% and more of their energy use (Panwar et al., 2011). In addition, distinguished Stanford professor Mark Z. Jacobson believes that producing renewable energy for nearly all supply needs could be achieved by the year 2050 (Delucchi & Jacobson, 2011). The estimated costs of such a transfer range but typically average around 1% -- 2% of world gross domestic product (Delucchi & Jacobson, 2011).

Typically, strategies to implement renewable energy sources begin with government incentives and legislation (Panwar et al. 2011). These policies appear to be effective and the continued incentives to get both industry and consumers to rely on more renewable energy sources should include financial gains to both of these groups as well as continuing legislation specifying how these sources can be implemented as technology increases (Delucchi & Jacobson, 2011).