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Tony Lee ’64 on climate change

The Simple Case for Climate Change

by Tony Lee

September 5, 2020

The evidence for global climate change is overwhelming. We know how it happened, what the implications are, and what can be done to mitigate and eventually neutralize the impact on the planet and human civilization.

We know:

  • Climate change is real;
  • Climate change is caused primarily by humans; and
  • We can mitigate the damage.

According to an April 2020 Gallup poll, 51% of Americans are “concerned believers” who attribute global warming to human actions and take the threat seriously. That means that 49% of Americans are not “concerned believers.” Of the 49%, according to Gallup, 28% are the “mixed middle” who hold a combination of views, and 21% are “cool skeptics” who express little to no worry about global warming and attribute higher temperatures to natural environmental changes.

51% versus 49%. Why is there such an even split, despite the fact that 97% of actively publishing climate scientists agree on human-caused warming?

Sometimes we overthink and overanalyze issues. Other times we allow misinformation and disinformation to cloud our understanding and judgment. The basic science of climate change is really very simple.

We’ve known about the climate-change problem for at least 30 years, but the problem began two-and-a-half centuries ago with the Industrial Revolution. Nations built factories and engines, ran them on fossil fuels, and thereby produced goods and services that improved most lives on the planet. Burning carbon-based coal, oil, and gas released an estimated one million gigatons of carbon dioxide (CO2) into the atmosphere. Although much of this CO2 was absorbed by the oceans, land, and growing plants, substantial amounts remained in the atmosphere. The following graph shows the dramatic spike in atmospheric CO2 generated by human beings during the Industrial Revolution over the last 250 years.


Prior to the Industrial Revolution, CO2 stayed at approximately
280 parts per million (ppm) to the mid-1700s, at which point
it started to increase steadily to the present level of 415 ppm

Records of average global temperature have been maintained for the past century and a half and show that the planet is heating up. Over the past 50 years alone the rate of increase has dramatically accelerated. In 2020, scientists declared “Nine of the ten warmest years in human history occurred in the last decade,” and they essentially made the same declaration in the year 2010 and before that in the year 2000. The following graph shows the increase in temperature over the past 170 years.


Average global temperature increased by approximately 1.3°C (2.3°F) over the past 170 years

Through the study of ancient air bubbles trapped in ice, oxygen isotope ratios which reveal temperatures, and other indirect measures of climate, scientists have shown that atmospheric CO2, global temperature, and sea levels are tightly correlated over the past 400,000 years.


CO2, average global temperature, and sea levels rise and fall together

It is also clear that relatively small changes in average global temperature cause large changes on the planet. For example, during the last ice age 18,000 years ago, my home near Boston, MA was under two miles of ice, despite the fact that average global temperature was only about 4.4°C (8°F) cooler than at present.

Business-as-usual climate models, assuming a perpetuation of today’s levels of fossil-fuel consumption, predict a 4°C (7°F) increase in average global temperature by the year 2100. Climate models predict that at 4°C, full-scale global collapse of human societies is probable.

The most serious concern can be seen in the upper right corner of the above triple graph where CO2 levels are shown to be 415 ppm. For the previous 400,000 years (and probably longer), all of life and evolution occurred in a relatively narrow range of CO2 and global temperatures. Now, at 415 ppm, we are 30% higher than the highest level of CO2 during that time period. From a geological time perspective, this is happening at lightning speed. Even after a temperature change of only 1.3°C, we have seen the dramatic melting of polar ice, the increase in wildfires and devastating storms, and the extinction of some species of birds and other animals. Animals, plants, and insects cannot adapt to this rate of change. We are experiencing, and will continue to experience, collapses of ecosystems, extinctions of species, and collapse of human societies.

We can mitigate the damage. We have the necessary technology and financial resources to “bend the curves” and thereby avert the coming ecological disaster. We need to reduce carbon emissions immediately and eventually attain net zero carbon emissions. But we lack the will to change our attitudes, lifestyles, and policies, and to redirect our wealth to where it is really needed.

We must understand that this is a matter of enormous urgency.

Tony Lee, Yale BA ’64 and Rutgers MBA ’69, was a licensed Certified Public Accountant. For the last 25 years of his professional career, he practiced as a forensic accountant and expert witness primarily in construction claims and real-estate disputes. Tony is a member of Elders Climate Action (Massachusetts Chapter), and has facilitated a series of webinars titled “Can We Stop Climate Change?” He lives in Wayland, MA.