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Trump carbon and the Paris agreement

Filed under: — david @ 17 November 2016

The recent US election has prompted cries that the decision on Earth’s climate has now been irrevocably made, that the US has unilaterally decided to scrap the peak warming target from the Paris agreement of 1.5 oC. What do the numbers say? Is Earth’s climate now irrevocably fracked?

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Carbon storage in WA state forests is too small and too risky to play a serious role as a climate change mitigation tool

Filed under: — david @ 4 November 2016

guest post by John Crusius, Richard Gammon, and Steve Emerson

The scientific community is almost universally in agreement that climate change (and ocean acidification) are severe threats that demand a rapid response, with putting a price on fossil fuel CO2 emissions being a top priority. Far and away the single biggest contributor to climate change is CO2 emissions from fossil fuel combustion. Indeed, global CO2 emissions from fossil fuel emissions in recent years have been roughly ten times higher than emissions from the next largest global source, land use change, including deforestation (Le Quéré et al., 2015). Despite the small size of carbon fluxes from forests, enhancing carbon storage in forests is often discussed in WA state as a tool to fight climate change. There was one such claim in the Seattle Times OpEd from October 21 by Mathew Randazzo. We challenge these claims that forest carbon sequestration in WA state can significantly help solve climate change. Randazzo does not spell out in any detail what he means. As always, details matter in such discussions, as the science is complex. We focus here on some of the best available science on the climate and carbon storage impacts of forests, and provide references at the bottom of this article from some of the premier scientific journals in the world.

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New On-line Classes and Models

Filed under: — david @ 6 February 2016

My free online class on entitled Global Warming I: The Science and Modeling of Climate Change has already served 45,000 people (started, not finished) in the four times that it’s run. Now it’s set up in a new format, called “on demand mode”, which allows people to start, progress, and finish on their own calendars. This would be an advantage if a teacher wanted to use the material to supplement a class; a new cohort of learners is launched every month, so the next class start date is never more than a month away.

A new, supplemental class to the first one has been added and will come online on Monday, called Global Warming II: Create Your Own Models in Python or Fortran. This takes advantage of new code-grading machinery at Coursera to automatically run your code through its paces. There is also a peer code-review step, where you will get feedback on your commenting and variable-naming skills, and provide feedback to others. The class gives detailed instructions to create simple models of: time evolution of global temperature, the ice albedo feedback drop into snowball Earth, an ice sheet, and a shallow-water circulation model. The class is intended for people who are new to programming, or new to Python, or wish to enhance their understanding and appreciation of some cool science of Earth’s climate system.

The classes are supported by the same interactive on-line interactive climate system models as before, at, with some new additions, both of which generate animations of their time-dependent solutions.

One is a Hurricane simulator using a model from Kerry Emanuel, which can demonstrate the sensitivity of ocean temperature, ocean mixing, and atmospheric structure on hurricane evolution.

The other, the Permafrost model, is a simulation of a soil or sediment column in which ice and methane hydrate can form. The model shows how the brine salinity thermodynamically excludes methane hydrate from forming until you get to the base of the permafrost zone, and also how long it takes to warm a soil column by warming the surface. This model shows why I do not believe in an imminent methane climate catastrophe from Arctic Ocean methane hydrates.

Free climate science / modeling class beginning Sept. 29

Filed under: — david @ 26 September 2014

Global Warming: The Science and Modeling of Climate Change is a free online adaptation of a college-level class for non-science majors at the University of Chicago (textbook, video lectures). The class includes 33 short exercises for playing with on-line models, 5 “number-cruncher” problems where you create simple models from scratch in a spreadsheet or programming language, and 8 “explainer” assignments where you explain some concept as you would to a smart 11-year old child (short, simple, clear), and exchange these with other students in the class for feedback. The discussion forums are very lively, as thousands of people from around the world make their way through the video lectures and exercises, lots to chat about. This is our third run of the class, so we’re getting the kinks out. We hope you find it useful. September 29 – December 31 2014.


The story of methane in our climate, in five pie charts

Filed under: — david @ 23 September 2014

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