Thoughts of a Lapsed Physicist

It is hard to even know where to begin to respond to President Trump’s decision to pull the U.S. out of the Paris Climate Accord. This is not because it was unexpected – the Trump Administration has sent several signals through its appointments that acceptance of and actions to address global warming and climate change is not on its agenda. What is most striking and disturbing, in this author’s opinion, is the distortion of facts and outright lying that defined the President’s withdrawal statement, and the impact that this withdrawal will have on our country and its standing in the world. While the decision by the U.S. to withdraw will not stop other countries, and states and localities in the U.S., from continuing their efforts to reduce carbon emissions, it will slow down the global effort and is a tragic decision on three grounds – moral, economic, and national security. I discuss each of these below.

To me the moral argument is clear – global warming arising from the introduciion of greenhouse gases into the atmosphere is a real physical phenomenon and is producing some positive but mostly negative climate change effects. And while countries such as the U.S. and China produce most of the gases that impact global climate its impacts are also felt by many others that had nothing to do with global warming – e.g., the island nations of the Pacific. If we accept the fact that in this world we are ultimately all in this together, and we all have an obligation to care for our fellow human beings, then we have a responsibility to be sensitive to these impacts of global warming. What seems to differentiate the Trump Administration from many of the the rest of us is summarized in a statement this week in the Wall Street Journal by two of President Trump’s top advisors, H.R. McMaster and Gary Cohn, who wrote: “The president embarked on his first foreign trip with a cleareyed outlook that the world is not a ‘global community’ but an an arena where nations, nongovernmental actors and businesses engage and compete for advantage.”

We each experience the physics of global warming when we step into an overheated car on a hot day – solar radiation from our high temperature sun passes through the windshield of the car and heats the upholstery, which heats up and in turn radiates energy, but from a much lower temperature source. This changes the frequency distribution of the reradiation so that while the sun’s initial radiation passed freely through the glass windshield, the radiation from the seat covers is now blocked from escaping by the windshield and the car heats up. In the case of global warming, the sun’s rays heat the earth and the oceans, which in turn reradiate at frequencies that are now blocked from escaping into space by the greenhouse gases introduced into the atmosphere. This creates the same heating effect for the planet as in the hot car situation.

It is important to emphasize that global warming is not an ideological belief but a phenomenon documented by physical measurements. The basic physics involves an energy exchange between the sun and the earth and what happens to that energy when it hits and is absorbed by the earth. The earth’s average temperature is determined by this exchange – the earth absorbs energy from the sun and reradiates back into space, and if something, such as volcano dust or greenhouse gases in the atmosphere disrupt this exchange the earth must change its temperature to remain in energy balance. Venus is an example of a planet where the balance has led to a very high planetary temperature, On earth the sun’s energy is absorbed by the continents and the oceans, leading to a subsequent complex exchange of energy of both with the atmosphere, creating the weather effects we call climate. Evidence of this energy absorption and exchange can be found in average air and ground temperature measurements, ocean surface temperature measurements and measurements of ocean temperatures at depth. It can also be seen in the expansion of water in the oceans when it is heated, leading to rising ocean water levels, in the melting of glaciers, in the migration of insects and animals in response to temperature changes, and in effects on weather such as changing precipitation patterns and increased frequency and intensity of storms. Well documented experimental observations exist for each of these impacts.

Positive impacts of global warming include improved agricultural production in cold climates, new shipping routes through the Arctic, and the fact that changes in weather patterns produced by warming can bring rainfall to previously arid areas. However, these positives are strongly outweighed by the negatives: glacial melting and addition of glacial ice to oceans is raising sea levels, which causes property destruction and saltwater intrusion into fresh water sources, extreme weather events are more frequent and intense as the atmosphere’s energy content increases, previously fertile areas become less productive due to excessive heat and reduced moisture, hydropower and thermal power generation are limited by reduced water availability, water supplies are disrupted by changing rainfall and ice melt patterns, diseases carried by insects move into new areas causing health problems, and species disappear due to new and extreme environmental conditions. In addition, national security issues are raised for the U.S. (and others) when increased water scarcity around the globe leads to population migrations within and across national borders, creating international tensions. The U.S. Defense Departmental has recognized this possibility in its planning for possible situations that could lead to deployment of U.S. military forces.

Finally a word about jobs. The President in his remarks stated that our withdrawal from the Paris Accord would save American jobs. This is a falsehood that must be rebutted. As I carefully documented in a recent article (‘Jobs? Investing in renewables beats fossil fuels’) posted on the website energypost.eu, and subsequently reposted on my blog website www.lapsedphysicist.org: “If a primary national goal is to create jobs in the energy sector, investing in renewable energy is considerably more effective than investing in fossil fuels. Solar and wind are no longer niche businesses, their widespread use addresses global warming and climate change, and their manufacture and deployment are powerful engines of economic growth and job creation.

The U.S. Congress must recognize this and put policies in place that accelerate their growth. Other countries recognize this potential and are moving rapidly onto this path, some even faster than the U.S. We must not be left behind as this energy transition unfolds in the next several decades, but we must also not forget the people who will be displaced from their jobs in traditional energy industries.”

The bottom line as I see it is that the President has lied to the American people about climate change and the potential harmful long term economic impacts of his policy. He claims to be acting in the national interest but the facts say something very different.