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| Isaac Feinn Class of 2019 |
About a year ago, President Trump announced the United States would begin pulling out of the Paris Accords; likewise, I posted on Facebook that I now rescinded my support for Mr. Trump on the issue of Climate Change. In my post’s wake, I received multiple requests from fellow conservatives asking me to study the science, both political and natural, that shrouds this “global conspiracy.” Well, I took a collegiate course called The Politics of Climate Change, so I’d love to share with you what I learned.
In recent years, the International Panel on Climate Change has submitted reports indicating that a scientific consensus of **97%** points to rising global temperatures resulting from human activity. This conclusion also states that with humanity’s current greenhouse gas emission rate, global temperatures could rise 2 degrees centigrade above average within the next 30-40 years, bringing with it detrimental climate change that would threaten food production, growth in domestic production, ecosystems, coastal land mass, and more.
Forget for a moment forget what the science says, since most of climate denialists reject it anyways. Instead, let’s ask the economists: according to this report (and many, many others like it), climate related disasters currently cost the US $240 billion a year, and if current climate trends continue, that number will soar to $1.9 trillion in the year 2100.
To put the former number in perspective, that’s enough money to pay the tuition of America’s 13.5 million college students; the latter is more than three times our annual military budget.
Last July, Syria announced it would join the Paris Accords, meaning the US is now quite literally the only country in the world not in the treaty.
So, why do we continue to abdicate climate action for the sake of economic growth, which in a terrible irony will cost the United states far more than it produces? If the argument could be summed up by its mantra, “America First”, then at best we’ll lag behind countries as they dominate clean-energy emerging-markets and in the process put our planet last.
Let’s revisit that pesky thing I told you to forget earlier: the science. Societal climate denial primarily results from the few scientists who ardently oppose the clear majority of their colleagues. These scientists often argue that the relationship between humans and climate change is non-causal, that the evidence for a causal relationship is inconclusive, or that the effects of climate change are oversold. In weighing these scientists’ credibility, we should examine their expertise.
Just as the diagnosis from a specialist ought to be valued more than one from a general doctor, so should the reports from a scientist with more peer-reviewed research, higher credentials, and experience in their domain be regarded higher than those with fewer qualifiers.
As it turns out, the scientists who possess more of these qualifiers almost unanimously conclude humans drive global warming. Many misconceptions about the veracity of climate denial stem from conflating the opinions of non-experts with experts and assuming that lack of affirmation equals dissent.
In a study conducted by Oreskes in 2004, 928 published papers submitted by climate scientists categorized as experts established a 100% consensus on anthropogenic global warming! To demonstrate the magnitude of this finding, Cook explains that this same level of certainty exists for the fact that smoking causes cancer, which society mostly views as indisputable.
What about the scientists you hear about who deny anthropogenic climate change? Regarding their opinions, expertise level drops significantly with dissenting opinions; the expertise of scientists forming a consensus on human-caused global warming of lower than 50% drops to nearly half that of the scientists who form the commonly reported 97%.
Interpreting the evidence of those expert scientists requires a general understanding of the greenhouse effect in order to see the link between human activity and changes in the environment. As I did not quite understand the mechanism behind global warming before my studies, I’ll briefly give an overview.
Certain gasses such as carbon dioxide or methane act as an insulator for heat and prevent its escape; these gasses exist in the atmosphere and trap heat on the earth’s surface. More greenhouse gasses produce more trapped heat, warming the planet. Life on earth requires some greenhouse effect to maintain proper temperatures, but excess greenhouse gas conduces dangerous global heating. As humans burn fossil fuels, carbon dioxide enters the atmosphere, contributing to the global greenhouse effect.
Greenhouse gas emissions have risen incrementally since the pre-industrial era, primarily from population and economic development, and have reached unprecedented atmospheric levels since the last 800,000 years. The International Panel on Climate Change (IPCC), which compiles thousands of scientific documents into a single report, states that “Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely [meaning 95-100% certain] to have been the dominant cause of the observed warming since the mid-20th century”.
Put simply, the line of action follows in this way: economic and population growth necessitate increased burning of fossils fuels, which produces carbon dioxide; then, this gas contributes to the greenhouse effect, which consequently warms the planet to the observed levels.
Studying the atmosphere, ice cores, global surface temperature, and countless more factors point to an unequivocal fact that the earth’s temperature has and continues to rise. The combined globally averaged ocean and land temperature have increased since 1880, exhibiting warming of .85 degrees centigrade. Although some areas have experienced warming more intensely than others, almost the entire globe has seen a rise in surface temperatures. This change also occurs consistently, as the IPCC reports that “Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850”. The past 30 years are very likely – a term indicating a confidence interval of over 90% - the warmest three consecutive decades in the last 800 years.
This should not illicit surprise, as humans now contribute nearly 30 billion tons of carbon dioxide to the atmosphere every year; if this amount of gas were compressed to its solid form, it would occupy nearly the same space as the white cliffs of dover.
Carbon dioxide remains one of the most efficient heat-trapping greenhouse gasses present in the atmosphere, and attempting to deny the effects of that sizeable annual atmospheric addition rejects common sense.
In fact, the data consistently correlates rising atmospheric carbon dioxide concentrations with increasing sea level and combined land and ocean surface temperatures. If the graphs showing land and ocean surface temperatures, sea-level, greenhouse gas concentration, and anthropogenic carbon dioxide emissions found on page four of the IPCC’s Summary for Policy Makers were placed on atop each other, one would think the positive slope of each line were identical.
The IPCC states:
“The evidence for human influence on the climate system has grown since [the last publication]. Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, and in global mean sea level rise; and it is extremely likely to have been the dominant cause of the observed warming since the mid 20th century”.
In addition, the number of cold nights has decreased, offering significant evidence for warming caused by increase greenhouse gasses. To illustrate why, consider if the earth had no greenhouse effect whatsoever; daylight temperatures would soar, while nighttime temperatures would plummet, like what occurs on the moon. Conversely, if the earth’s atmospheric composition mirrored a planet with excess greenhouse gasses like Venus, both day and night-time temperatures would remain hot. The earth exists somewhere in-between these two examples, but recent data shows that night-time temperatures have begun to rise faster than daytime temperatures, which suggests that greenhouse gasses trap the heat overnight: much like Venus, a planet overrun with greenhouse gasses. These reports have not emerged from the opinion of a small group of scientists, but from the consensus of thousands of scientific documents over decades of research.
Many critics of anthropogenic climate change combat this data by postulating that the earth naturally cycles through warm periods caused by occurrences such as increased solar activity or volcanic eruptions. However, these claims result from either scientific ignorance or a disregard for current evidence.
In response to the solar activity assertion, the period of observed global warming has not occurred concurrently with a period of increased solar energy output, as studies show that “there are no observations that indicate significant changes in the solar irradiance.” The sun’s energy output has not deviated from its normal cycles, and has remained constant in recent decades. Moreover, if global warming has occurred from increased solar irradiance, then the solar energy would need to first pass through all layers of the atmosphere and consequently warm them. Most of the observed atmospheric warming has occurred in the lower half of the atmosphere, while the upper half – the stratosphere - has experienced some cooling. Rising greenhouse gas emissions can account for this, as the greenhouse effect would primarily warm the lower levels of the atmosphere from trapping the heat near the surface of the earth.
In response to the volcano assertion, Neil Degrasse Tyson explains that the total human contribution of atmospheric carbon dioxide constitutes 98% more than that of even the highest estimate of volcanic carbon dioxide. “The measured increase in the CO2 in the atmosphere,” he says, “tallies with the known amount we are dumping there by burning coal, oil, and gas.” Additionally, carbon dioxide produced from volcanos weighs more than gas produced from burning fossil fuels, offering researchers a distinct signature to identify the source of atmospheric carbon dioxide. Tyson states that this information conclusively determines that the overwhelming majority of atmospheric carbon dioxide did not originate from volcanos.
In arguably his most powerful assertion, he says, “The observed [global] warming is as much as predicted from the measured increase in carbon dioxide.” To deny that humans cause global warming when the worldwide temperature increase matches the amount that should result from human emissions boldly discounts the hallmark of scientific fact: to make accurate predictions.
Denying that humans cause climate change not only prioritizes the opinions of a less qualified minority, but also opposes decades of evidence; both of which inherently imply that either thousands of scientists who have studied in this field for years have faulty or misinterpreted data, or that a conspiracy exists among the overwhelming majority to falsify the data to further the interests of certain groups.
These implications defy practical thought, and the most reasonable conclusion follows that perhaps these scientists have reliable data. The IPCC’s report presents a problem with disastrous consequences if left unchecked, and this issue deserves realistic thought if only for the magnitude of those consequences. With every consecutive year, the data for anthropogenic climate change expands while the state of the climate declines. This science is indeed conclusive based on its consistency and the qualifications of those who gather it, and the need for action quickly becomes the next biggest dilemma.
Isaac Feinn, of Louisville, Ky., is a junior McConnell Scholar studying biology and political science.