GEO 109 responds to Kailey: current warming trend is real and caused by human activities

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In his op-ed piece on climate change, Francis Kailey ’18 asserted that global warming is really not happening; rather, he claimed that it is just the result of urban development around meteorological stations, the so-called urban heat island effect.

Further, he claimed that scientific consensus is meaningless and just an attempt to silence “many qualified individuals”, that climate change happens naturally (and thus, apparently, what is happening today must be natural) and that the percentage of global CO2 emitted by man is negligible from a climate standpoint.

He closed his engaging essay by positing that those concerned about climate change are really just advocating de-developing the western world into a primitive utopia!

As I am a climate scientist and am currently teaching the course Geological Perspectives on Global Warming (GEO 109), in which we explore modern climate systems, natural mechanisms of climate change and the many natural recorders of climate, as well as the impact of fossil fuel combustion on global temperatures, I thought it would be engaging for members of the class to respond to any one of the points made by Mr. Kailey.

What follows is a compilation of nearly 40 students’ responses.

Like many climate denier arguments, most start with a kernel of truth but rapidly become unmoored from reality. The urban heat island effect is an example. It is well known and well understood, and it most certainly does NOT explain the ~1°C of warming measured globally over the past 150 years (Ruddiman, 2014).

The observation that sea surface temperatures, which are not affected by urban development, show exactly the same temperature trends as do land records from sparsely populated regions clearly demonstrate real planetary warming.

Sea level rise, retreating mountain glaciers, and melting permafrost are but a few of the myriad lines of evidence that confirm significant ongoing climate change. This is absolutely irrefutable, and no legitimate scientist denies the demonstrable evidence of warming.

It is also well known that global climate has always been changing.

From the sauna-like conditions of the Cretaceous, during which broad-leafed trees covered both poles, to the Ice Ages, when an ice sheet reached as far south as present-day Long Island and Cincinnati, climate has never been static.

But does this mean that 20th Century warming is natural? Evidence from ice and ocean cores reveals that Earth has oscillated between ice ages and “interglacial” periods for millions of years, and temperature swings were ~8°C.

Interglacials lasted ~12,000 years and the one we are currently in began ~11,500 years ago (Ruddiman, 2014). So, in the absence of human-derived greenhouse gases, we should be cooling slowly into the next ice age.

There is no evidence that near the end of any prior interglacial period that temperatures ever warmed at a rate of ~1°C per century.

The current CO2 level of over 400 ppm is unprecedented and, given the efficacy of atmospheric CO2 to absorb outgoing long wave radiation and warm the atmosphere ­­— a phenomenon that was documented more than 100 years ago by Nobel laureate Svante Arrhenius — it should be of no surprise that global temperatures have “come off the rails”.

It is true that the CO2 emitted annually by humans is only 3% of that emitted by nature, and thus one might wonder what all the fuss is about.

The trick is that ALL the CO2 emitted by nature is balanced by natural processes. Degassing of CO2 from the oceans is balanced by photosynthetic uptake of CO2 by phytoplankton in the oceans.

Respiration of plants on land emits about 100 gigatons of CO2 annually, but an equal amount is taken up by photosynthesis to make land plants.

Even volcanic emissions of CO2 are balanced by the geochemical uptake of carbon when rocks are weathered into soils (Ruddiman, 2014). Natural processes are akin to a bathtub with 1 gallon per minute of water entering from the faucet and 1 gallon per minute draining, with the result being no accumulated water in the tub.

The human component adds a small amount to the 1-gallon per minute entering the tub, to say 1.03 gallons per minute. With a constant drain of 1 gallon per minute, water begins to accumulate and steadily rise, just as atmospheric CO2 levels are rising from the 280 ppm at the beginning of the Industrial Revolution to over 400 ppm today.

Now, does it really matter what 97% of scientists say?   Maybe they’re just lining their pockets with research grants! In fact what really matters is evidence and data.

Stuff you cannot really argue about, like the lockstep relationship between atmospheric CO2 levels and global temperatures (Ruddiman, 2014). This is an irrefutable relationship and to suggest that,for the first time in millions of years, temperature will not track CO2 levels is absurd. The scientific evidence of human-induced climate change is overwhelming.

In a recent paper, Cook et al. (2013) reviewed about 12,000 peer-reviewed articles published between 1991 and 2011. Of those papers that clearly took a position based on scientific evidence, over 97% concluded that current climate change is caused by human activities.

In addition, the organizations that represent the thousands of scientists in fields related to Earth’s climate unanimously support the assertion that greenhouse gases emitted by human activities are the primary driver of ongoing climate change.

These organizations include the National Academy of Sciences, the American Association for the Advancement of Science, the Geological Society of America and the American Meteorological Society, among many others.

Recently, even the U.S. Defense Department has weighed in on the topic. The Pentagon, hardly a bastion of liberal dogma, concluded that climate change poses an immediate threat to national security due to the increased risks of food and water shortages, infectious disease and the resultant geopolitical unrest.

Maybe they’re all wrong, but I wouldn’t bet on it! To be sure, consensus by itself is not a proof of anything and it can be flat wrong. Galileo’s heliocentric view of the solar system was met for decades with resistance by the geocentric religious orthodoxy of the day.

Eventually, it was Galileo’s scientific evidence that held sway. Today, the overwhelming consensus of climate scientists is backed up by decades of accumulating evidence.

It is the climate deniers that are clinging to a line of argument that is devoid of supporting evidence.

The arguments repeated by Mr. Kailey are the standard fare of the climate deniers.   These arguments might sound convincing but they are nonsense, and could be easily disregarded if they were not also used by members of congress, whose votes have been paid for by the fossil fuel industry, to purvey doubt and delay action for decades.

This delay has made it ever more difficult and costly to mitigate the effects of ongoing warming.

Freedom of speech is a sacred right in this country and especially at institutions of higher education. However, we should expect more at Union than just the parroting of nonsense.

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