A federal judge has climate science questions. Here are the answers.
Today’s courtroom drama unfolding in San Francisco will come in the form of a “tutorial” on climate science, not a debate.
Federal Judge William Alsup, a quirky, inquisitive man who previously taught himself the Java programming language for a 2012 lawsuit involving Oracle and Google, will be the only one asking questions. There will be no direct debate between lawyers representing the people of the State of California and those for the defendant oil companies.
In a court document, Judge Alsup narrowed his focus to eight specific questions regarding climate science (in bold below). In the two weeks since the questions were posted, climate scientists have attempted to crowdsource the best, most succinct answers. (I’ve further summed them up in just a few words, in parenthesis.):
- What caused the various ice ages (including the “little ice age” and prolonged cool periods) and what caused the ice to melt? When they melted, by how much did sea level rise? (Natural changes in the Earth’s orbit and the amount of greenhouse gases. Sea level rose a lot — more than 400 feet.)
- What is the molecular difference by which CO2 absorbs infrared radiation but oxygen and nitrogen do not? (Three-atom molecules vibrate more easily than two-atom molecules.)
- What is the mechanism by which infrared radiation trapped by CO2 in the atmosphere is turned into heat and finds its way back to sea level? (Greenhouse gases like CO2 emit extra trapped energy from the sun, warming the surface.)
- Does CO2 in the atmosphere reflect any sunlight back into space such that the reflected sunlight never penetrates the atmosphere in the first place? (Yes, but not enough to matter.)
- Apart from CO2, what happens to the collective heat from tail pipe exhausts, engine radiators, and all other heat from combustion of fossil fuels? How, if at all, does this collective heat contribute to warming of the atmosphere? (The amount of heat from the sun that’s trapped by greenhouse gases is 100 times more than direct heat from fossil fuel burning.)
- In grade school, many of us were taught that humans exhale CO2 but plants absorb CO2 and return oxygen to the air (keeping the carbon for fiber). Is this still valid? If so, why hasn’t plant life turned the higher levels of CO2 back into oxygen? Given the increase in human population on Earth (four billion), is human respiration a contributing factor to the buildup of CO2? (Yes, this is still valid – but this process is roughly carbon neutral, so there is no major impact on the climate. And human respiration of CO2 is 10,000 times too small to matter to the climate.)
- What are the main sources of CO2 that account for the incremental buildup of CO2in the atmosphere? (Fossil fuel burning and deforestation)
- What are the main sources of heat that account for the incremental rise in temperature on Earth? (Human activities are likely responsible for 93 to 123 percent of recent global warming. It can go over 100 percent because we’re canceling out what would be natural cooling.)
The crowd-sourcing effort (with references) was coordinated by NASA’s Gavin Schmidt, who in an email to Grist said he doesn’t actually expect there to be much disagreement over the science in today’s courtroom tutorial. Chevron, one of the defendants, is not planning to deny evidence at all in its explanations. In fact will refer Judge Alsup to the Intergovernmental Panel on Climate Change — the gold standard of mainstream climate science.
“Despite the attempted interventions from the fringe,” Schmidt wrote, “ I doubt that the defendants or plaintiffs will be making much hay with the science.”
Even if disagreement is unlikely, Andrew Dessler, a climate scientist from Texas A&M University — who penned a Twitter thread of answers to Alsup’s questions — hailed the uniqueness of today’s court activities.
“Obviously, I wish these issues were not still being debated in court, since they’re not being debated in the scientific community, but I also appreciate the deliberate approach the judge seems to be taking,” he wrote to Grist.
No matter what the oil industry lawyers argue today, these facts are well established: Human activities are by far the dominant cause of modern climate change, and only a sharp reduction in our emissions — which means our use of oil — will help solve the problem.