Global Warming and Climate Change have been hotly debated topics over the past few years. As signs of change such as the hole in the ozone layer and melting of arctic ice develop, many people feel this is due to anthropogenic or man-made causes such as burning of fossil fuels. Others believe that any global warming is a natural occurrence and would happen regardless of human influence. This debate has strong proponents on both sides.
Currently there has been a debate in the U.S. House of Representatives regarding new powers effective January 2, 2011 that allow the Environmental Protection Agency (EPA) to impose greenhouse gas (GHG) regulations under the Clean Air Act. On February 2, 2011 the House Energy and Commerce Committee held a hearing on “H.R. 910, The Energy Tax Prevention Act of 2011”, which aims to amend the Clean Air Act so the EPA cannot use it to regulate GHG. A request was made to have another hearing to focus on the science of the issue, and on March 8, 2011 the Committee held a hearing entitled “Climate Science and EPA’s Greenhouse Gas Regulations”. The Republicans brought 2 expert witnesses to debunk claims that global warming is being negatively affected by human influence, and the Democrats brought 5 expert witnesses to try to convince the Committee that there is a valid problem.
I read through the statements from this hearing with interest, and found that unfortunately it seems politics are having too high of an influence on science. The Republicans’ main interest seemed to be in proving that concerns about the effects of global warming are merely a scare tactic, and that stemming the human activities that may affect the environment would be too costly in terms of money and jobs. Each side had witnesses with many scientific credentials, and they all seemed to have some valid points. However the reasoning of their points seem to fall very much along parameters of the goals of the politicians, making it difficult for a layman to decide which argument to put more faith in.
One of the Republicans’ witnesses was John R. Christy, Distinguished Professor of Atmospheric Science from the University of Alabama. He stated that although attributing extreme weather events to anthropogenic influence was popular; as weather systems are dynamic it is likely for extreme weather events to happen often. He cited the 20th Century Reanalysis Project which seeks to generate weather maps as far back as 1871, and has found that the three major indices related to extreme events, the Pacific Walker Circulation, the North Atlantic Oscillation, and the Pacific-North America Oscillation, do not show a trend of increased circulation since 1871. Therefore, he believes there is no supporting evidence that human factors influenced the major circulation patterns during that time period. Christy goes on to state that we should expect extreme events to occur and plan for them; and that the measured climate history we have of about 130 years is not large enough to be representative of possible climate extremes. Christy also supports the Republicans’ argument for costliness of action by stating, “Developing countries in Asia already burn more than twice the coal than North America does and that discrepancy will continue to expand. The fact that our legislative actions will be inconsequential in the grand scheme of things can be seen….”
The next witness was Roger A. Pielke Sr. from the University of Colorado and Colorado State University. Pielke believes that just focusing on carbon dioxide and a few other greenhouse gases was too narrow, and missed other important human influences on the climate. He also gave explanations of the difference between global warming and climate change. According to Pielke, “Global warming is typically defined as an increase in the global average surface temperature. A better metric is the global annual average heat content measured in Joules. Global warming involves the accumulation of heat in Joules within the components of the climate system. This accumulation is dominated by the heating and cooling within the upper layers of the oceans. Climate Change is any multi-decadal or longer alteration in one or more physical, chemical and/or biological component of the climate system.” He also states that “Detection of robust anthropogenic signals in regional climate predictions is seldom possible within…timescales of a few decades.” Pielke also spent time denigrating the CCSP (U.S. Climate Change Science Program) and IPCC (Intergovernmental Panel on Climate Change) as only using the research of a few scientists and excluding valid scientific perspectives. From an outside layperson’s perspective, it seemed as though he might be airing “sour grapes”.
Another witness was Christopher B. Field, Director of Department of Global Ecology at Carnegie Institute for Science. Field discussed “a series of robust conclusions from climate science… including two 2010 reports from the US National Academy of Sciences, “Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia” (Solomon 2010), and “Advancing the Science of Climate Change” (Matson 2010), the 2009 report from the US Global Change Research Program, “Global Climate Change Impacts in the United States” (Karl et al. 2009) and the Fourth Assessment Report of the IPCC (IPCC 2007a, c, b).” His conclusions seemed quite contrary to some of the other witnesses: “Global warming is unequivocal and primarily human-induced. Climate changes are underway in the United States and are projected to grow. Widespread climate-related impacts are occurring now and are expected to increase. Climate change will stress water resources. Crop and livestock production will be increasingly challenged. Coastal areas are at increasing risk from sea-level rise and storm surge. Risks to human health will increase. Climate change will interact with many social and environmental stresses. Thresholds will be crossed, leading to large changes in climate and ecosystems. Future climate change and its impacts depend on choices made today.”
Dr. Knute Nadelhoffer, PhD Director, University of Michigan Biological Station followed by stating that climate change is real and that science has irrefutably shown that rising concentrations of greenhouse gases are resulting from human activities and that there are no other scientific explanations for climate changes occurring. Nadelhoffer brought a letter to append to his testimony signed by 149 scientists from Michigan who agreed with his ideas. Richard C. J. Somerville of the Scripps Institute added his testimony that the most recent research and latest observations demonstrates that climate change is occurring and in many cases is exceeding earlier projections. He cites the IPCC’s most recent Assessment Report, AR4 from 2007, but also refers to newer findings documented in the Copenhagen Diagnosis which was published in 2009.
The Copenhagen Diagnosis was compiled by 26 scientists from 8 different countries, and was not affiliated with any organization. The findings included that global carbon dioxide emissions from fossil fuels had increased by 40% between 1990 and 2008, and that even if emissions were stabilized at current levels, within twenty years there would be a 25% probability of warming of 2 degrees Celsius. A delay in taking action could result in irreversible changes to continental ice sheets, Amazon rain forests and West African monsoons. “The risk of transgressing critical thresholds (“tipping points”) increases strongly with ongoing climate change. Thus, waiting for higher levels of scientific certainty could mean that some tipping points will be crossed before they are recognized.” Somerville points to evidence of warming in air temperatures, ocean temperatures, melting ice, and rising sea levels. He concludes: “The greenhouse effect is well understood. It is as real as gravity. The foundations of the science are more than 150 years old. Carbon dioxide in the atmosphere amplifies the natural greenhouse effect and traps heat. We know carbon dioxide is increasing because we measure it. We know the increase is due to human activities like burning fossil fuels because we can analyze the chemical evidence for that. Our climate predictions are coming true. Many observed climate changes, like rising sea level, are occurring at the high end of the predicted changes. Some changes, like melting sea ice, are happening faster than the anticipated worst case. Unless mankind takes strong steps to halt and reverse the rapid global increase of fossil fuel use and the other activities that cause climate change, and does so in a very few years, severe climate change is inevitable. Urgent action is needed if global warming is to be limited to moderate levels.”
As a layperson it is hard to sort out the competing arguments of scientists and decide first if climate change is indeed happening, and second if it is happening whether anthropogenic influence is the cause, and third what if anything should be done to reduce any human activities that may influence this process. I believe that since it could be decades before scientists have enough data to draw conclusive opinions, it is better to err on the side of caution. We know that burning fossil fuels, deforestation in the Amazon and Indonesia, and polluting the oceans are all bad for the environment. Allowing corporations to influence lawmakers to weaken regulations so corporations can make a higher profit will ultimately result in disasters such as the BP Horizon oil spill in the Gulf. Arguing that we should not reduce our level of pollution because other countries may not reduce their emissions seems like a political rather than scientific point. Reducing emissions, deforestation and pollutants is a worthwhile goal even if the extent that it might affect climate change is not yet determined.
Works Cited:
Broder, John. “At House E.P.A. Hearing, Both Sides Claim Science.” The New York Times. 09 March 2011. <http://www.nytimes.com/2011/03/09/science/earth/09climate.html>
U.S. House. Energy and Commerce Committee. Climate Science and EPA’s Greenhouse Gas Regulations. (H.R. 910 The Energy Tax Prevention Act of 2011) March 8, 2011. <http://energycommerce.house.gov/hearings/hearingdetail.aspx?NewsID=8304>
The Copenhagen Diagnosis, 2009: Updating the World on the Latest Climate Science.
I. Allison, N.L. Bindoff, R.A. Bindschadler, P.M. Cox, N. de Noblet, M.H. England, J.E. Francis, N.
Gruber, A.M. Haywood, D.J. Karoly, G. Kaser, C. Le Quéré, T.M. Lenton, M.E. Mann, B.I. McNeil,
A.J. Pitman, S. Rahmstorf, E. Rignot, H.J. Schellnhuber, S.H. Schneider, S.C. Sherwood, R.C.J.
Somerville, K. Steffen, E.J. Steig, M. Visbeck, A.J. Weaver. The University of New South Wales
Climate Change Research Centre (CCRC), Sydney, Australia, 60pp.
Sojourn 
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