The issue of whether human activities threaten to change climate has stirred a fiery debate world all over. In this debate, there are people who support the idea while others reject it. The debate notwithstanding, the issue of climate change is real, as we have seen its effects in the recent past.
This reality must have hit the stakeholders hard leading to convergence of different summits to address the issue. The Copenhagen summit took place last month not to mention the signing of Kyoto Protocol.
Does it mean that these summits converge to come up with a solution to a problem that does not exist? Could it be we are trying to tame a natural disaster? This paper handles such issues exploring if human activities influence climate change, and if they do, then how and to what extent. This paper will also look into the possibility of climate change due to non-human or natural occurrence.
After immense scientific studies on human involvement in climate change, it is clear that human activities greatly influence climate change (Easton, 2006, p. 9). To understand this better, it is good that we define global warming and its causes. According to Milbourn (2009), global warming is the projected and observable increase in the average temperature of Earth’s atmosphere and oceans.
The Earth’s average temperature rose by 0.6 degrees Celsius in the 20th Century (United Nations (UN) Public Inquiries Unit, 2002). The greatest known cause of global warming is the increase of green house gases like carbon dioxide, water vapor, ozone, sulfur hexafluoride, hydro fluorocarbons, and methane (UN Public Inquiries Unit, 2002). Science research has proved that burning of fossil fuels lead to emission of carbon dioxide.
How does global warming happen? As sunlight hits the Earth’s surface, a smaller amount of the light is absorbed to warm the Earth but the larger amount is radiated back to the atmosphere at a longer wavelength than the sun light (Milbourn, 2009). Study shows that, greenhouse gases absorb some of these longer wavelengths before they escape into the atmosphere.
After this absorption, these greenhouse gases reflect the heat energy generated back to the Earth. This reflection of heat energy back to the Earth by the atmosphere is known as “greenhouse effect” or global “warming” (Norma, 1993, p. 44).
With this knowledge, we can critically analyze activities that lead to emission of these gases into the atmosphere and determine whether they are human in nature or not. The human activities that leads to the emissions of these gases are such as; use of motor vehicles, which emit hazardous gases.
Carbon dioxide, which is the principle contributor of global warming, is produced when coal and fossil fuels are burned to produce energy in different applications. According to Milbourn (2009), use of fossil fuels accounts for 80-85% of carbon dioxide in the atmosphere currently.
Deforestation that is, cutting down of trees also contributes to increase of greenhouse gases in the atmosphere. When man cut trees down and burns them, the carbon that is contained in trees is released into the air as carbon dioxide.
Other human activities include farming; the use of fertilizers and other chemicals in farming releases nitrous oxide, which is a hazardous gas that causes about 10% of air pollution (Cynthia & Daniel, 1995). Changes due to land use accounts for 15-20% of the current carbon dioxide emissions in the atmosphere (Milbourn, 2009).
Methane, the second largest important greenhouse gas comes from cattle rearing, rice cultivation, decaying materials in landfills and during oil drilling (Norma, 1993, p. 44). Studies show that if there were no human involvement, the natural methane levels in the atmosphere would be 145% less than the current levels (EPA, 2009).
Nitrous oxide results from various human activities like agricultural and industrial practices. Human activities have increased levels of nitrous oxide by 15% over the natural levels (Milbourn, 2009). People use chlorofluorocarbons in air conditioning, refrigeration and as solvents.
These gases as aforementioned still contribute to global warming. Finally, ozone; that is, the lower part of atmosphere also causes global warming. Even though this gas is produced naturally, studies have shown that different gases produced from human activities react to form ozone, a relatively important greenhouse gas.
Who causes the emission of these greenhouse gases? The answer is man. Because of these human activities, there has been increased global climate change in the past few years (Cunningham & Cunningham, 2004, p. 96). This is evident from the rate at which the ice caps are melting, the unpredictable change of patterns of weather, and the rise in levels of seawater.
Drought continues to be experienced in many parts of the world as shortage of water becomes more pronounced. High intensity cyclones and hurricanes continue to wreck havoc in various parts of the earth (Global Warming, 2010). Katrina and Tsunami are real examples of effects of human activities that have occurred in our times.
From the U.S Global Change Research Information Office, an article written by Cynthia and Daniel on the impacts of climate change on agriculture and food claims that, “the change in climate change that is being experienced today will automatically affect food supply in the world.
This is due to water supply drop on crops which may limit their growth, the rise in global temperature will also affect crop growth, and thus it will be very difficult for the world to predict on future food supply” (Cynthia & Daniel, 1995). Man will continue to suffer from pangs of hunger; actually, some parts of Africa are already grappling with reality of global warming as they try to face hunger that has become a normal phenomenon in most places.
In the wake of these events and revelations, it is clear that human activities are involved directly in climate change. The fact that even critics agree that greenhouse gases are the chief cause of global warming, man cannot be exempted from it. It is unfortunate that since time immemorial, man has come up with ways of putting the blame on someone else and the issue of global warming is not different. We are blaming everything else apart from the main culprit, human beings.
May be global warming is not for real. In the last few years, different groups of scientists have come out strongly to refute the widely accepted theory that human beings are responsible for global warming. One of such people is Singer (1997) who said, “There does not exist today a general scientific consensus about the importance of greenhouse warming from rising levels of carbon dioxide.
Instead, most scientists now accept the fact that, actual observations from Earth satellites show no climate warming whatsoever.” Many other people including over 17,000 scientists have thrown weight behind this issue.
This group of people including geophysicists, physicists, meteorologists, climatologists, and environmental scientists states that, “there is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gases is causing or will, in the foreseeable future, cause catastrophic heating of the Earth’s atmosphere and disruption of the Earth’s climate” (Bast, 2001).
Apparently, science is not in a position to pin point the extent by which human activities have contributed to global warming. According to Mathews (2003), the earth did not start warming in the recent past; on contrary, the Earth was even warmer in the Middle Ages than it is today.
Scientists working on impacts of climate in the United Kingdom concluded that throughout 1990s, the Earth had been warmer than any particular point in the last millennium (Mathews, 2003). Many scientists and environmentalists bought this idea and called for immediate action to cut down emission of greenhouse gases into the atmosphere. However, this does not mean that these researchers were right.
Another group of researchers from Harvard University conducted ‘temperate proxies’ research whereby, they used things like historical accounts, ice nubs, and tree hoops to determine prevalent temperatures at different sites around the globe. They established that the medieval temperatures were very hot before drastic cooling of the world in 1300 (Mathews, 2003).
Therefore, there is a possibility that scientists in contemporary world are in haste to draw conclusions from researches carried over a very short period of time say, 10 years. Theories are proved after looking closely to well-documented peer reviewed materials and this withstanding, there is a possibility that human activities have nothing to do with global warming.
Maybe, “what has been forgotten in all the discussions about global warming is a proper sense of history” (Mathews, 2003). An alarmist group of scientists is emerging trying to blow things out of proportion after compiling few segments of scientific data that is not supported by any core scientific literature.
For an idea to be accepted as a fact in science, it must go through rigorous sessions of study and reviews, a component that is conspicuously lacking in today’s scientific claims that human beings are contributors of global warming.
There is no concrete proof that human beings are involved in global warming. What we have is a sketchy ‘through the glass’ assumption drawn from few excerpts from recent studies. The point here is that, there are no clear-cut parameters to prove that human activities lead to global warming. Given the fact that all the greenhouse gases also occur naturally, how can scientist ‘scale up’ the amount that is dangerous in the atmosphere?
Global warming is the projected and observable increase in the average temperature of Earth’s atmosphere and oceans. Whether human activities contribute to global warming or not, remains a point of contention. The debate is immense and each group is holding tight to its claims. Climate reformers have continued to brand critics ‘business minded coterie’ while critics have always branded reformers findings’ ‘science consensus’. This turns out to be a game of finger pointing.
However, after a critical review of both sides, it is clear that global warming is real and it is here to stay unless stakeholders take immediate mitigation factors to alleviate the prevailing conditions. It is easier said that human activities do not contribute to global warming than grappling with the realities of global warming.
People are dying of hunger and related catastrophes under our very own eyes. Sitting back and watching as people perish form repercussions of what could have been prevented does not justify cowing away from criticism. Time for procrastination was yesterday; today it is time to act on the issue of climate change.
Bast, J. (2001). Scientists Do Not Believe Human Activities Threaten To Disrupt the Earth’s Climate. Retrieved 9 Feb. 2010, from,
Cunningham, M., & Cunningham, W. (2004) Principles of Environmental Science. McGraw Hill International. 2nd Ed.
Cynthia, R., & Daniel, H. (1995). Potential Impacts of Climate Change on Agriculture And Food Supply. Consequences, 1, 2-4.
Easton, T. (2006). Taking Sides Clashing Views on Environmental Issues. Guilford:
Dushkin Pub Group. 12th Ed. EPA. (2009). Greenhouse Gas Emissions. Retrieved January 29, 2010, from,
Global Warming. (2010). Global Warming: Climate Change Greenhouse Effect. Retrieved 29 Jan. 2010, from,
Mathews R. (2003). Middle Ages Were Warmer Than Today, Say Scientists. Retrieved 9 Feb. 2010, from,
Milbourn, C. (2009). EPA: Greenhouse Gases Threaten Public Health And The Environment / Science Overwhelmingly Shows Greenhouse Gas Concentrations At Unprecedented Levels Due To Human Activity. News Releases issued by the
Office of Air and Radiation. Retrieved 9 Feb. 2010. From,
Norma K. (1993). Native perspective on climate change, in Impacts of Climate Change On Resource Management in the North. University of Waterloo: Ontario.
Singer, F. (1997). Hot Talk, Cold Science: Global Warming’s Unfinished Debate Oakland, CA: The Independent Institute
The United Nations Public Inquiries Unit. (2002). Global Climate Change. Retrieved 9 Feb. 2010. From,