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My Turn/William Gran: CO2 is the primary cause of climate change

  • GRAN


Monday, April 10, 2017

Deniers of human caused global warming and climate change often falsely suggest current warming results from natural causes, which is absolutely wrong. Before the Industrial Revolution global climate change was natural, but since then human caused global warming and climate change has grown to overwhelm natural causes.

Natural causes such as variations in solar radiation, volcanic eruptions, and changes in earth’s orbit, tilt and oscillation are still present, but they are rendered insignificant by human causes such as emissions of greenhouse gases and land use changes.

NASA compares natural and human caused forces of global warming over the last 50 to 65 years at its website, which shows most natural causes have resulted in cooling while human causes have resulted in warming. NASA states: “The studies used a wide range of independent methods, and provide multiple lines of evidence that humans are by far the dominant cause of recent global warming. Most studies show recent natural contributions have been in the cooling direction, thereby masking part of the human contribution and in some cases causing it to exceed 100 percent of the total warming.”

Professor Will Steffen at the Australian National University and Owen Gaffney of the Stockholm Resilience Centre, in a research paper published in the journal The Anthropocene Review, found human impacts are resulting in climate changing 170 times faster than from natural causes. We are causing climate to change in one century what would, on average, take 17,000 years from natural causes.

In a Guardian article, February 12, 2017, Professor Steffen states “For four billion years the rate of change of the Earth system has been a complex function of astronomical and geophysical forces plus internal dynamics: Earth’s orbit around the sun, gravitational interactions with other planets, the sun’s heat output, colliding continents, volcanoes and evolution, among others. We are not saying [over the last 45 years these natural] forces have disappeared, but in terms of their impact in such a short period of time they are now negligible compared with our own influence. The human magnitude of climate change looks more like a meteorite strike than a gradual change.”

Scott Pruitt, the new EPA Administrator, denies all this. His opinion expressed at his confirmation hearing: “I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact, so no, I would not agree that [CO2 is] a primary contributor to the global warming that we see.” He says this without offering any credible scientific alternative (because there is none) to the human caused climate change we are experiencing. In fact there is not “tremendous disagreement about the degree of impact”, there is extremely strong agreement – over 97 percent agreement among climate scientists published in peer-reviewed journals. Both NASA and NOAA agree.

Gina McCarthy, the last EPA Administrator, said “The world of science is about empirical evidence, not beliefs. When it comes to climate change, the evidence is robust and overwhelmingly clear that the cost of inaction is unacceptably high. I cannot imagine what additional information the Administrator might want from scientists for him to understand that.”

Making claims without evidence is not new for this administration, but certainly goes directly to its credibility and its understanding of climate science. Denying that carbon dioxide is a primary contributor to global warming, and thus climate change, is denying nearly 200 years of climate science.

While Pruitt denies CO2 is the primary cause of global warming, atmospheric concentration of CO2 “just keeps going up and up” according to Ralph Keeling, Director of the Scripps Institute for Oceanography’s carbon dioxide monitoring program. The Mauna Loa Baseline Atmospheric Observatory in Hawaii measured record-breaking increases of 3 parts per million in 2015 and 2016. Pieter Tans, lead scientist at NOAA’s Global Greenhouse Gas Reference Network stated “The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last ice age.”

In 2013 Mauna Loa Observatory announced atmospheric levels of CO2 reached a daily average above 400 parts per million for the first time in history. “CO2 concentrations haven’t been this high for millions of years.” By 2016 ,scientists said global CO2 levels would likely not fall below 400 parts per million — perhaps ever again. Keeling said “I think we’re essentially over for good.”

In 2007 the Supreme Court ruled that the EPA has the authority to regulate heat-trapping gases that contribute to global climate change and “could not sidestep its authority unless it could provide a scientific basis for its refusal.” Pruitt’s denialism has no scientific basis whatsoever and Trump’s proposed budget cuts to the EPA “sidestep its authority” to regulate greenhouse gases without any “scientific basis for its refusal.”

This cannot stand! Resist!

William Gran, now retired, was an adjunct instructor at Greenfield Community College on global warming and climate change. He can be reached at whgran@gmail.com