Our climate has crossed a threshold and we as a society need to understand
what this means. Unfortunately, this is an extremely difficult task to
accomplish for many reasons.
To help with this understanding, I have provided a few critical pieces of information that allow a
greater insight into the challenge as a whole.
December 22, 2008 Climate Collapse is Real - The Venus Syndrome James Hansen, Director of the NASA Goddard Space institute - the foremost US Government climate modeling agency - gave a presentation at the American Geophysical Union annual meeting in San Francisco last week (16,000 scientists attended the annual festivities). The rate of CO2 change today is 10,000 times higher than at any time in the known paleo-history of the planet. The threat of the Venus syndrome is very real. Runaway, irreversible climate change is a very real probability: Both of these statements according to Dr. Hansen. Here's a quote lifted from the notes of his PowerPoint presentation:
"There may have been times in the Earth’s history when CO2 was as high as 4000 ppm without causing a runaway greenhouse effect. But the solar irradiance was less at that time. What is different about the human-made forcing is the rapidity at which we are increasing it, on the time scale of a century or a few centuries. It does not provide enough time for negative feedbacks, such as changes in the weathering rate, to be a major factor. There is also a danger that humans could cause the release of methane hydrates, perhaps more rapidly than in some of the cases in the geologic record. In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect. If we also burn the tar sands and tar shale (a.k.a. oil shale), I think it is a dead certainty."
The importance of the venue for these statements can not be under-stated. The AGU is the largest organized body of scientists on the planet.
December 20, 2008 Berknes Lecture http://www.columbia.edu/~jeh1/
The First Reason - Reticence Dr. Hansen spends a lot of time in this paper talking about reticence, or as the American Heritage Dictionary defines it: 1. Inclined to keep one's thoughts, feelings, and personal affairs to oneself. 2. Restrained or reserved in style. 3. Reluctant; unwilling. Scientific reticence is one of the fundamental reasons that we are in the situation that we are in. A scientist absolutely must be correct or his livelihood, and ultimately his family are in jeopardy, just the like the rest of us. If we lose our jobs, what does that mean for our families? So to safeguard their personal interests, scientists heavily caveat their academic writings. They temper their findings with words like "possible", "likely" "could happen", "may", "might" etc.
The exceptions, these caveats, allow a scientists to speak very directly about their typical narrow focus of study, and to apply contingencies for unexpected outcomes. This way a scientist can publish research and experimentation results, without having to analyze the entire world. The caveats make up for imperfect knowledge of the unknown. And in this huge science of climate, there are plenty of unknowns.
Scientific Reticence and Sea Level Rise, James Hansen, Environmental Research Letters, May 2007
The Second Reason -
Catastrophic Sea Level Rise
This letter emphasizes the logical connection between a
historical Earth with a vastly higher sea level and warmer temperature, to a
future Earth with the same temperature as the historic Earth. This is the
reality of the sea level issue. A warmer planet melts more ice, it's very
simple. The Intergovernmental Panel on Climate Change (the IPCC - the
conservative scientific consensus that Hansen talks about)
explicitly refuses to include dynamical ice sheet changes in their projection of
sea level rise because - we simply do not understand these processes.
This attitude exemplifies scientific reticence. We do however, know very well that dynamical ice sheet changes have caused extraordinary sea level rises in the past. We have evidence that supports 80 foot sea level rises in less than a century, that have occurred multiple times during the past several million years. Yet the IPCC will not include even a cursory analysis of the risks and possibilities in their report. This is why the Director of the United States Government Climate Modeling Agency has written this report - to bring this important fact to the attention of the public.
The IPCC projects that our planet will warm 2 to 3 degrees in the next century (don't forget that the IPCC projections are very likely significantly conservative). As Dr. Hansen points out not once, but twice in his paper, the last time temperatures on this planet were 2 to 3 degrees warmer, sea level was 50 to 114 feet higher.
The IPCC 4th Assessment Summary for Policy Makers says this about sea level rise:
Because understanding of some important effects driving sea level rise is too limited, this report does not assess the likelihood, nor provide a best estimate or an upper bound for sea level rise. The projections do not include uncertainties in climate-carbon cycle feedbacks nor the full effects of changes in ice sheet flow, therefore the upper values of the ranges are not to be considered upper bounds for sea level rise. They include a contribution from increased Greenland and Antarctic ice flow at the rates observed for 1993-2003, but this could increase or decrease in the future.
The IPCC AR4 Climate Change 2007: The Physical Science Basis, Summary for Policy Makers adds:
The last time the polar regions were significantly warmer than present for an extended period (about 125,000 years ago), reductions in polar ice volume led to 4 to 6 meters (13 to 20 feet) of sea level rise.
The BIG CAVEAT
AR4 Physical Science Summary: Models used to date do not include
uncertainties in climate-carbon cycle feedback nor do they include the full
effects of changes in ice sheet flow, because a basis in published literature is
lacking. The projections include a contribution due to increased ice flow from
Greenland and Antarctica at the rates observed for 1993-2003, but these flow
rates could increase or decrease in the future. Larger values cannot be
excluded, but understanding of these effects is too limited to assess their
likelihood or provide a best estimate or an upper bound for sea level rise.
VERY IMPORTANT NOTE: The IPCC projections include discharge from Antarctica and Greenland at their rates observed between 1993 and 2003. It is very important to understand that we have likely crossed a threshold after the beginning of the 21st century where ice-sheet discharge and melt will be at the absolute minimum double or triple the previous decade, and likely an order of magnitude greater (ten times) and possibly two or more orders of magnitude greater (100 or 1,000 times greater) Another obvious comment about "scientific reticence". In The BIG CAVEAT paragraph above - The IPCC says that the "...flow rates could increase or decrease in the future". Very true, even on this rapidly warming planet, the flows could decrease from the ice sheets, we just don't know how the dynamical ice discharge mechanisms works, so the caveat was introduced. It's a little far-fetched to think that any decrease could be long lived or significant, unless of course we have a climate flip - which would send the planet careening into an ice age of course. It has happened about 44 times in the last 100,000 years, so it is not at all that far-fetched after all...
New Mega Reports
United Nations Human Development Report 2007 / 2008, Fighting Climate Change: Human Solidarity in a Divided World
Why does our society have, especially Americans, disregard climate science so feverishly? The answers are many and varied. To fully comprehend the climate crisis dilemma, a thorough understanding of societies perceptions of climate change is mandatory. It is not until a significant majority of our population understands the extreme nature of the climate crisis that actions appropriate will be made. This 384 page report attempts to understand why it is that humankind downplays the climate crisis.
US Geological Survey - Abrupt Climate Change (784 pages) The USGS is one of the most conservative science organizations in existence. More conservative than the IPCC. They are worried about abrupt climate change as shown in their new mega report:
http://www.usgs.gov/newsroom/article.asp?ID=2091
Arctic Climate Impact Science (ACIS)- An update since the ACIA: April 2008 - This study finds that ALL Arctic ecosystems are changing. They are changing much faster and with greater impacts than previously found in the Arctic Climate Impact Assessment in 2005. Melting of Arctic Sea ice and the Greenland ice cap is accelerating severely and the report warns of these systems reaching irreversible and catastrophic tipping points
Hotter and Drier: March 2008 - Rocky Mountain Climate Organization: 17 government agencies 17 private businesses and 11 non profits summarize the climate crisis in the American Rockies: 50 reports and 125 sources.
70% greater warming than the global average.
100% mortality of the Rocky Mountain's Lodgepole Pine forests in 3 to 5 years because of Pine Bark Beetle: 12% of the total forested are in the U.S. Rockies.
IPCC: Intergovernmental Panel on Climate Change
The following are critical components of the IPCC Fourth Assessment issued in November 2007, The Physical Science Basis, Summary for Policy Makers
Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level. Best estimates for average global temperature by the end of the 21st century are: the low scenario is 1.8 degrees C (3.2 degrees F) warmer, the high scenario is 4.0 degrees C (7.2 degrees F); and the worst case scenario is 6.4 degrees C (11.5 degrees F).
The following items are from the fourth IPCC report, November 2007
Eleven of the last twelve years (1995-2006) rank among the twelve warmest years in the instrumental record of global surface temperature (since 1850).
The rate of warming of the planet increased nearly 25% since 2000 as compared with the period 1906 to 2000.
Global GHG emissions due to human activities have grown since pre-industrial times, with an increase of 70% between 1970 and 2004.
Carbon dioxide (CO2) is the most important anthropogenic GHG. Its annual emissions grew by about 80% between 1970 and 2004.
The long-term trend of declining CO2 emissions per unit of energy supplied reversed after 2000.
Most of the observed increase in globally-averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.
During the past 50 years, the sum of solar and volcanic forcings would likely have produced cooling. Global atmospheric concentrations of CO2, methane (CH4)and nitrous oxide (N2O) have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values determined from ice cores spanning many thousands of years.
Atmospheric concentrations of CO2 (379ppm) and CH4 (1774 ppb) in 2005 exceed by far the natural range over the last 650,000 years.
Global increases in CO2 concentrations are due primarily to fossil fuel use, with land-use change providing another significant but smaller contribution.
It is very likely that the observed increase in CH4 concentration is predominantly due to agriculture and fossil fuel use. The IPCC projects an increase of global GHG emissions by 25-90% between 2000 and 2030.
Most of the observed increase in globally-averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.
