Question

Pg 8 ' eerm han gtohal warning to describe the efects of warming due inte s de poay) Ei to the accumulation of greenhouse gases to. (6 points) Evidence suggests that average global temperatures have been much higher in the geolo compard o the current avernge globai temperature If'so, then explin why we should be concerned about global cimate change now?

Answer 1

1. Greenhouse effect is the warming of the earth and the lowest layer of the atmosphere known as the troposphere which is caused by the presence of water vapour, carbon dioxide, methane and some other gases present in the air. These gases are together known as greenhouse gases, water vapour out of these having the greatest effect. The atmosphere allows most of the visible light from sun to pass through and reach the earth's surface. When the earth is heated by the sunlight, it reflects certain part of the light back to the space as infrared radiation. This infrared radiation tends to get absorbed by the greenhouse gases present in the atmosphere, thus, raising its temperature. The heated atmosphere in turs sends radiations back to the earth's surface. Global warming points out only to earth's rising surface temperature whereas climate change consists of warming and all the side effects caused by warming such as melting of glaciers, heavy rainstorms and frequent droughts. Therefore we can also state this in a more elaborate way as : Global warming is a part of the much larger problem that is caused by humans known as climate change. Whenever global warming is talked about, it is always referred to the warming caused by humans which is due to the rapid increase in the carbon dioxide and other greenhouse gases that are emitted because of people burning coal, oil and gas. Whereas climate changes can mean both human caused or natural ones such as ice ages. Apart from burning fossil fuels, humans can cause climate change by emitting small particles of aerosol pollution that reflect the sunlight into the atmosphere by changing earth's landscape from carbon storing forests to farmlands.

2. Greenhouse gases, basically CO2, have controlled the climate changes in the past. This time humans are the cause of climate change because they are affecting the CO2 emissions. The climate has always been changing. There were ice ages and relatively warmer periods when alligators were found in spitsbergen. Ice ages have occurred in a hundred thousand years of cycle and there were periods that have appeared to be warmer than present despite CO2 levels being lower than they are now. Greenhouse gases mainly the carbon dioxide, have made various climate changes in earth's history. When these were reduced the climate of the earth got colder. And when they were increased, the climate of the earth for warmer. When levels of carbon dioxide gets changed rapidly, this resulted in global;l warming that was highly disruptive and sometimes caused mass extinctions. Humans today are emitting extremely high quantities of carbon dioxide, which is at a rate that is even faster than the most destructive climate changes in the earth's history. Life developed in ecocene, when there was high carbon dioxide in the atmosphere because the greenhouse gases were in balance with the carbon in the oceans and the weathering of the rocks. Life, oceans and atmospheric gases has millions of years to adjust to those balances of carbon dioxides. But during a lot of times, the earth's atmosphere has jumped abruptly in the past, in pretty much the same way as it is happening today. This happened mainly because of large emissions of greenhouse gases into the atmosphere just like human emissions of greenhouse gasses presently. Those abrupt global warming events were highly destructive for life causing extinction of large masses. Symptoms of those events like increasing sea levels, ocean acidification and large jump in global temperatures are occurring today also by human cause climate changes. Therefore, even though global temperatures have been lower as compared to geological past, human emissions of carbon dioxide needs to stop. Hence the concern for global climate change is still intact as increasing global warming symptoms can lead to massive life extinction and other natural life threatening symptoms.