How Humans Have Contributed to Climate Change

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Ernest Ebo Jackson

Climate change refers to change in average weather patterns and can be caused by both natural processes and human activities. In the past, the earth's climate has been affected by natural factors such as changes in solar output and the discharge of volcanic ash. In fact, the planet has been through many periods of cooling and warming. The last period of major cooling ended about 10,000 years ago. The physical evidence that suggests that the earth’s climate is changing is truly overwhelming. The world’s glaciers are retreating and disappearing, extreme weather is occurring more often now than in the past, the sea’s level and temperature is on the rise and it’s becoming more acidic, increased evaporation is drying out the earth’s supply of fresh water found in lakes and rivers, heat waves kill thousands in Europe, uncontrollable forests fires are destroying forests reserves in places like Australia and Africa, and increasing atmospheric temperature is raising the budget of many families in tropical countries use in cooling their homes. Need I say more? The sun's warmth heats the surface of the earth, which in turn radiates energy back to space. Some of this radiation, which is nearly all in the infrared spectrum, is trapped in the atmosphere by greenhouse gases. For instance, water vapor strongly absorbs radiation with wavelengths between 4 and 7 micrometers, and carbon dioxide (CO2) absorbs radiation with wavelengths between 13 and 19 micrometers. The trapped radiation warms the lower atmosphere, or troposphere. Some heat then finds its way back down to the Earth's surface, making it hotter than it would otherwise be. This is the greenhouse effect. Carbon dioxide levels in the atmosphere over the last 400,000 years show a rise since the industrial revolution. Analysis of ice in a core drilled from an ice sheet such as the Antarctic ice sheet enables scientist to arrive at this conclusion. But since when did humans becoming aware of the potentially adverse effects of Carbon dioxide emissions on the climate? As early as 1827, French polymath Jean-Baptiste Fourier predicts an atmospheric effect keeping the earth warmer than it would otherwise be. He is the first to use a greenhouse analogy. Also in 1957, US oceanographer Roger Revelle warns that humanity is conducting a "large-scale geophysical experiment" on the planet by releasing greenhouse gases. Colleague David Keeling sets up first continuous monitoring of CO2 levels in the atmosphere. Keeling soon finds a regular year-on-year rise. Over the years, there have been many conferences aimed at finding solutions to climate change or global warming. In 1985 for instance, there was a major international conference on the greenhouse effect at Villach, Austria, which warned that greenhouse gases will "in the first half of the next century, cause a rise of global mean temperature which is greater than any in man's history." This could cause sea levels to rise by up to one meter, researchers say. The conference also reports that gases other than carbon dioxide, such as methane, ozone, CFCs and nitrous oxide, also contribute to warming. The world’s nations however have not been united in their quest to curb global warming or climate change. Many nations have been selfish, especially developed ones, seeking first to achieve or maintain economic growth and thus world dominance rather than make the sacrifices needed to reverse the negative trend of climate change. . A revisit to some historical event will help buttress this point. 1995 proved to be the hottest year recorded to date. In March, the Berlin Mandate is agreed by signatories at the first full meeting of the Climate Change Convention in Berlin. Industrialized nations agree on the need to negotiate real cuts in their emissions, to be concluded by the end of 1997. In 1996, at the second meeting of the Climate Change...
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