By Dr. Kevork Abazajian
No one can argue against the immense gains science has brought people in the quality and longevity of their life. Average life expectancy after the age of ten in America has improved from the fifties to the late seventies today. Child mortality before the age of 5 has gone from over 40% globally in 1800 to less than 1% in America today. The medical science advances leading to longer and healthier lives are a stunning example of the power of science to reduce and eliminate perils.
As a physicist, one of my favorite examples of how science and engineering increasingly accurately predict the outcome of a set of actions is external ballistics, or the behavior of a projectile in flight. A highly studied and applied subject in military operations, external ballistics includes the flight of a bullet, an artillery shell, or an intercontinental ballistic missile. The goal is, of course, to eliminate an enemy threat. Being able to do that accurately and predictably is vital.
The physical effects that have to be addressed include those that are obvious, like wind and air density. Yet there are less obvious ones. One effect is called gyroscopic or spin drift, where a spinning projectile will experience a side force even in completely calm air. Another is the Magnus effect, which alters the way that spinning projectiles respond to wind. For long range projectiles like artillery or ballistic missiles, the Earth’s rotation affects the projectile’s motion significantly and also must be taken into account in calculating its trajectory. This is called Coriolis drift.
This is all to say the goal of eliminating or reducing an imminent threat relies on taking into account numerous complex physical mechanisms. Scientists and engineers calculate and thoroughly test these mechanisms in a set of experiments that can validate the calculations. The well-tested physics is integral to incorporate in order to successfully predict the outcome of projectile motion and achieve a certain goal, namely the elimination of a threat or completion of an objective.
As Americans, we face today a global, planetary-level threat that will have catastrophic consequences: climate change. The Bulletin of the Atomic Scientists, founded by Manhattan Project scientists in 1945, identifies climate change as a threat second only to nuclear war. Our understanding of the threats from climate change comes from applying the same scientific principles: detailed calculations followed with validation by data. The same way we are able to predict the trajectory of a projectile with initial conditions and subsequent forcings, we are able to predict the trajectory of our climate due to its current conditions and subsequent forcings. Validation of climate models with data already has been done using paleoclimate data as well as data from the 1991 Pinatubo Volcano eruption. The conclusions of these forecasts are as universally accepted by scientists as anything gets.
The same scientific principles forecast that business-as-usual greenhouse gas emissions will lead to about a 4°C warming globally by the year 2100. The goal for the international Paris Agreement was to mitigate this threat and remain within a 2°C warming. The harms due to greater warming are vast, including threats to agriculture, increasingly extreme weather events, an eventual sea-level rise to where over 20 million Americans currently live, and destruction of the property on that land. Climate change is already suppressing property values on the US coast, and destroying over 70,000 square miles of trees in the Rocky Mountains.
As recently reported by U.S. military leaders, unchecked climate change has implications for national security since climate change increases the likelihood of international and civil conflict, state failure, mass migration and instability in regions of strategic interest.
We must take action immediately to avert these threats, since our greenhouse gas budget to stay under warming goals is quickly being consumed. Given this threat to our planet and our national security, action on climate cannot be further delayed.
Yet, the Trump administration stands alone among 195 world leaders in not acknowledging the reality of anthropogenic climate change and the need for action to mitigate it. In fact, a recent Nature Climate Change analysis of the Trump administration's proposed actions concludes “Any delays to mitigation or cuts to renewable energy research by the U.S. will likely render the 2°C target unachievable if a global precedent is set.” Unfortunately, the Trump administration is indicating it will proceed with business-as-usual use of greenhouse gas emitting fossil fuels, even planning to accelerate their usage and further eliminating federal assistance in development of carbon-neutral energy sources.
Continuing to ignore climate change threats will displace at least 20 million Americans from their homes and cause $1 trillion dollars in loss of property value, in addition to the environmental and societal implications to Americans and world wide. These forecast threats are as well-established as anything can be in science, and it is an imperative that we aim policies with the proper trajectories to stop this threat.