0.17 Energy: global warming change  (Page 3/8)

Implications of climate change

Some doubt that global warming is underway. The Author of this book believes otherwise. He has personally witnessed the gradual retreat, since 1995 of glaciers in the Northern Hemisphere (Alaska), the Southern Hemisphere, Patagonia (in Southern Chile) and in the high Andes of Peru. And there is abundant, well vetted evidence of global warming in Polar Regions, especially the Arctic, from Alaska to Greenland to Siberia and beyond. Indeed there are some indications that the Arctic is warming twice as fast as the rest of the world. See for example, “The Melting North”, The Economist , June 16, 2012, pp.3-10. The subtropics have not been unaffected. Temperatures in Northern Kenya have become so hot during daytime that farming, school attendance and other daily undertakings has become a struggle for rural villagers. For example, students now attend classes from 6 to 9 PM and from dawn for two more hours, to avoid the heat of midday.

While clearly in some important regions, the earth has been warming, can we be certain about the causes? Human activity that generates greenhouse gases is surely a major part of the problem. How much is difficult to say, but it is clearly the view of most (not all) members of the relevant scientific communities that the prime cause is human activity. This view is clearly stated in the Landmark Report of the Intergovernmental Panel on Climate Change (IPCC), “Summary for Policymakers, in Climate Change 2007, The Fourth Assessment Report.” See also Nicholas Stern “The Economics of Climate Change: The Stern Review”, Cambridge University Press, 2007. This has been called the anthropogenic view of global warming.

However, human activity has not been the only cause of global climate change. Major shifts in ocean current (such as the Gulf Stream or the Humboldt Current) could account for a portion, since the oceans are never in equilibrium. Ali Kilcik, “Regional Sun-climate Interaction”, Journal of Atmospheric and Solar-Terrestrial Physics , Vol. 67(16): 1573-79, November 2005. But even more important may be changes in solar cycles, according to some studies. Certainly there have been interaction between solar phenomena and warming. One study has suggested that half the warming over the 20 ^th century may be explained by solar changes. N. Scafetta and B.J. West, “Phenomenological Solar Contribution to 1900-2000 Surface Global Warming”, Geophysical Research Letters , Vol. 33(5), March 2006.

Many predict looming calamity from global warming. In March 2012 two Australian climate scientists asserted that this is the last decade the world has to act before we pass the “tipping point” of 2 degree Celsius warming. This would be especially harmful for tropical, emerging nations. Warnings from other sources are even more dire. The MIT Joint Program on the Science and Policy Change forecasts that with no policy changes to curb emissions of greenhouse gases, global average surface temperatures could rise by as much as 5.2 degrees centigrade, bringing with it disaster. The MIT group also maintains that even if policy changes do succeed in limiting 21 ^st century emissions to desired level, the median predicted warming level would be 2.3C. Mark Jaccard, “An Economist’s Journey”, Science , Vol. 343(6169), January 2014, pp.371-372.