Dire projections of 4 to 6°C temperature rise by 2100 (deadly to most life) conservative, could be 10 to 12°C!

Dennis Bushnell is the chief scientist at the NASA Langley Research Center in Hampton, Virginia.  Below are excerpts from an article he wrote for The Futurist magazine, with links added by eco-S for this post.

Original article: Conquering the Climate Crisis, Dennis Bushnell, The Futurist

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Carbon-dioxide levels are now greater than at any time in the past 650,000 years, according to data gathered from examining ice cores. These increases in CO2 correspond to estimates of man-made uses of fossil carbon fuels such as coal, petroleum, and natural gas…

…I believe we should act in accordance with the precautionary principle: When an activity raises threats of harm to human health or the environment, precautionary measures become obligatory, even if some cause-and-effect relationships are not fully established scientifically.

…several “warming events” have radically altered the life on this planet throughout geologic history. Among the most significant of these was the Permian extinction, which took place some 250 million years ago. This event resulted in a decimation of animal life, leading many scientists to refer to it as the Great Dying. The Permian extinction is thought to have been caused by a sudden increase in CO2 from Siberian volcanoes. The amount of CO2 we’re releasing into the atmosphere today, through human activity, is 100 times greater than what came out of those volcanoes.

During the Permian extinction, a number of chain-reaction events, or “positive feedbacks,” resulted in oxygen-depleted oceans, enabling overgrowth of certain bacteria, producing copious amounts of hydrogen sulfide, making the atmosphere toxic, and decimating the ozone layer, all producing species die-off. The positive feedbacks not yet fully included in the IPCC projections include the release of the massive amounts of fossil methane, some 20 times worse than CO2 as an accelerator of warming, fossil CO2 from the tundra and oceans, reduced oceanic CO2 uptake due to higher temperatures, acidification and algae changes, changes in the earth’s ability to reflect the sun’s light back into space due to loss of glacier ice, changes in land use, and extensive water evaporation (a greenhouse gas) from temperature increases.

The additional effects of these feedbacks increase the projections from a 4°C–6°C temperature rise by 2100 to a 10°C–12°C rise, according to some estimates…

…Between now and then, ocean methane hydrate release could cause major tidal waves, and glacier melting could affect major rivers upon which a large percentage of the population depends. We’ll see increases in flooding, storms, disease, droughts, species extinctions, ocean acidification, and a litany of other impacts, all as a consequence of man-made climate change. Arctic ice melting, CO2 increases, and ocean warming are all occurring much faster than previous IPCC forecasts, so, as dire as the forecasts sound, they’re actually conservative.

These threats exist in addition to the documented economic, geopolitical, and national-security issues associated with the continued use of fossil fuels. The finite nature of coal, oil, and natural gas will instigate higher energy prices and greater energy price disruptions…

…Because of these climatic, economic, national-security, and geopolitical drivers, it makes sense to alter our energy sources and uses in an expeditious manner…

…It’s not technology, capacity, or costs per se that are slowing humanity’s move to renewables, but rather conservatism, our attachment to the industries and strategies we’ve already invested money in (sunk costs), and lack of creative strategic planning for the inevitable demise of fossil fuels.

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