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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.):

  1. 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.)
  2. 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.)
  3. 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.)
  4. 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.)
  5. 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.)
  6. 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.)
  7. What are the main sources of CO2 that account for the incremental buildup of CO2in the atmosphere? (Fossil fuel burning and deforestation)
  8. 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.

Continued here:  

A federal judge has climate science questions. Here are the answers.

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Your plane’s ETA is wrong, and it’s the climate’s fault

Your plane’s ETA is wrong, and it’s the climate’s fault

By on 13 Jul 2015commentsShare

To most people, hopping on a plane from Hawaii to the East Coast and getting in way earlier than expected is just a stroke of luck — little more than an excuse for a self-congratulatory coffee from one of the 200 Starbucks lining the airport terminal. But to Hannah Barkley, a PhD student in oceanography at MIT who is about to put you to shame, it’s a scientific phenomenon worth investigating.

Barkley enjoyed one of these lucky trips on her way back from doing field work in Hawaii not too long ago. Back on campus, she asked Kris Karnauskas, a researcher in the Woods Hole Oceanographic Institution’s Geology and Geophysics Department, why her flight was so off, and the two subsequently got lost in decades worth of wind speed data and flight times between Honolulu and major West Coast cities. Long story short: There’s a strong link between those lucky flights and fluctuations in climate.

In a paper published today in Nature Climate Change, Karnauskas, Barkley, and two of their colleagues report that about 88 percent of the variability in domestic flight times is linked to variability in atmospheric circulation. This is largely thanks to a combination of El Niño events — those annoyingly irregular bouts of high Pacific Ocean temperatures — and the so-called Arctic Oscillations — winds that circulate the North Pole, periodically confining the cold arctic air to the pole or letting it escape down to the mid-latitudes.

As the climate changes, both of these atmospheric factors will likely change, meaning the average length of a flight could change, too — which, in turn, could have a real impact on climate change. (Phew, that’s a lotta “change.”) Here’re the numbers from a press release:

According to the study, there are approximately 30,000 commercial flights per day in the U.S. If the total round–trip flying time changed by an average of one minute, the amount of time commercial jets would spend in the air would change by approximately 300,000 hours per year. This translates to approximately 1 billion gallons of jet fuel, which is approximately $3 billion in fuel cost, and 10 billion kilograms of CO2 emitted, per year.

“We already know that as you add CO2 to the atmosphere and the global mean temperature rises, the wind circulation changes as well—and in less obvious ways,” says Karnauskas.

Depending on whether that change is an increase or a decrease in average flight times, this could be good news or bad news for the rest of us, climactically speaking. Karnauskas eventually wants to look at all global flights, according to the press release. In the mean time, perhaps domestic airlines should take note:

In reflecting on the findings of this project and the simple question Barkley had initially asked, Karnauskas says one of the biggest surprises is that the airline industry doesn’t seem to be aware of the flight time patterns beyond the day-to-day.

“The airline industry keeps a close eye on the day-to-day weather patterns, but they don’t seem to be addressing cycles occurring over a year or longer,” he says. “They never say, ‘Dear customer, there’s an El Niño brewing, so we’ve lengthened your estimated flight duration by 30 minutes.’ I’ve never seen that.”

Maybe you haven’t noticed, Karnauskas, but we humans aren’t the best at planning for — or even acknowledging — climate variability.

Source:
Air Travel and Climate: A Potential New Feedback?

, Woods Hole Oceanographic Institution.

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Your plane’s ETA is wrong, and it’s the climate’s fault

Posted in Anchor, FF, G & F, GE, LG, ONA, Plant !t, Radius, Uncategorized | Tagged , , , , , , , , , , , | Comments Off on Your plane’s ETA is wrong, and it’s the climate’s fault