You breathe in toxic chemicals too.

No, not Tyra Banks and Riyo Mori, climate models that is.

ES&T Online News: Models underestimate global warming impacts

Modelers don’t purposely err on the conservative side, says Marika Holland of the National Center for Atmospheric Research, but some processes “are just not well understood, and because of that have not been incorporated into climate models.” Holland has published model results on the fate of sea ice and coauthored the recent paper showing that ice is melting faster than models predicted. There are many reasons for the underestimates, she says. For example, models don’t fully capture heat transport between ocean and atmosphere, or faster warming as reflective ice gives way to darker, heat-absorbing waters.
But Rahmstorf says that modelers might unwittingly make models more conservative by applying “one-sided filters”, weeding out models that clearly overestimate the changes seen so far, but hanging onto ones “where everything is too well behaved and stable.”

Scientists are human too. The political and social climate in the US have been harsh to people who overestimate the effects of climate change. So, modeling scenarios that deviate significantly from accepted limits or runaway uncontrollably are discarded. Models are sets of assumptions based on underlying theory. If the theory of a particular sub-process is not clearly understood, then the assumptions become subjective. In a social climate that is waiting to pounce on an overestimate as example of negating the entire global warming phenomenon, assumptions made are conservative. This is not necessarily a bad thing, but it comes at a price! As more observations come in, it does become clear that sometimes, things are happening faster and at greater magnitudes than our model predicted.

Well, possibly the biggest climate change science news of the day, sequestration with a twist. Now if we can only get those friendly little carbon dioxide molecules to march down a couple of miles down to the ocean sediments to sequester themselves! But seriously, it will take a lot of pumping.

Permanent carbon dioxide storage in deep-sea sediments — House et al., 10.1073/pnas.0605318103 — Proceedings of the National Academy of Sciences

Stabilizing the concentration of atmospheric CO2 may require storing enormous quantities of captured anthropogenic CO2 in near-permanent geologic reservoirs. Because of the subsurface temperature profile of terrestrial storage sites, CO2 stored in these reservoirs is buoyant. As a result, a portion of the injected CO2 can escape if the reservoir is not appropriately sealed. We show that injecting CO2 into deep-sea sediments <3,000-m water depth and a few hundred meters of sediment provides permanent geologic storage even with large geomechanical perturbations. At the high pressures and low temperatures common in deep-sea sediments, CO2 resides in its liquid phase and can be denser than the overlying pore fluid, causing the injected CO2 to be gravitationally stable. Additionally, CO2 hydrate formation will impede the flow of CO2(l) and serve as a second cap on the system. The evolution of the CO2 plume is described qualitatively from the injection to the formation of CO2 hydrates and finally to the dilution of the CO2(aq) solution by diffusion. If calcareous sediments are chosen, then the dissolution of carbonate host rock by the CO2(aq) solution will slightly increase porosity, which may cause large increases in permeability. Karst formation, however, is unlikely because total dissolution is limited to only a few percent of the rock volume. The total CO2 storage capacity within the 200-mile economic zone of the U.S. coastline is enormous, capable of storing thousands of years of current U.S. CO2 emissions.

James Hansen: Obama’s Canada trip defines our critical carbon moment | Comment is free | guardian.co.uk

The tar sands of Canada constitute one of our planet’s greatest threats. They are a double-barrelled threat. First, producing oil from tar sands emits two-to-three times the global warming pollution of conventional oil. But the process also diminishes one of the best carbon-reduction tools on the planet: Canada’s Boreal Forest.

This forest plays a key role in the global carbon equation by serving as a major storehouse for terrestrial carbon – indeed, it is believed to store more carbon per hectare than any other ecosystem on Earth. When this pristine forest is strip mined for tar sands development, much of its stored carbon is lost. Canada’s Boreal Forest is also the reservoir for a large fraction of North America’s clean, fresh water, home to some five billion migratory birds, and some of largest remaining populations of caribou, moose, bear and wolves on the planet.

Nothing more to say, except that he does a good job of connecting both the inefficiency of the extraction process, a carbon source, and the destruction of the boreal forest, the removal of a carbon sink. If carbon accounting was in place, the economics would not work. Harper knows this, hence all the aggressive PR to get ahead of the game.