Tuesday, October 27, 2015

Elevated CO2 Levels Directly Affect Human Cognition, New Harvard Study Shows (?)

Just the first part of a new article from the professional Warmists at "Think Progress" below.  In my usual pesky way, I went straight back to the first journal article cited below.  I append that Abstract.  What the academic authors did was to take a 600ppm level of CO2 as the normal indoor level of CO2 and compare it with much higher levels, starting with 1,000 ppm.  On their measure of decision making, they found reduced performance at the 1,000 ppm level.  

So this finding is completely irrelevant either to the present or to the foreseeable future.  The present ambient atmospheric level is around 400 ppm.  Even using an improbable straight-line projection, it will be a very long time before we get to an ambient 1,000 ppm level of CO2.

I could look at other evidence on the question.  Greenhouse workers, for instance, seem to have no problems working amidst a concentration of around 1,000 ppm and levels of CO2 go up to 8,000ppm in U.S. submarines, but given the dishonest way the article below started out, I am not inclined to waste time looking further

And don't forget:  Around two thirds of all published medical and psychological research findings are not replicable -- i.e. wrong.  The findings below are good candidates for falling into that category

In an email, Craig Idso comments:  "Years ago we took CO2 measurements inside various buildings. I distinctly remember the values we recorded at the local high school, which were well over 1000 ppm from all the human exhalation inside the classrooms from the students. The concerns cited below are an absolute joke and the "scientists'" recitation of them is a disservice  to real science.

In a landmark public health finding, a new study from the Harvard School of Public Health finds that carbon dioxide (CO2) has a direct and negative impact on human cognition and decision-making. These impacts have been observed at CO2 levels that most Americans — and their children — are routinely exposed to today inside classrooms, offices, homes, planes, and cars.

Carbon dioxide levels are inevitably higher indoors than the baseline set by the outdoor air used for ventilation, a baseline that is rising at an accelerating rate thanks to human activity, especially the burning of fossil fuels. So this seminal research has equally great importance for climate policy, providing an entirely new public health impetus for keeping global CO2 levels as low as possible.

In a series of articles, I will examine the implications for public health both today (indoors) as well as in the future (indoors and out) due to rising CO2 levels. This series is the result of a year-long investigation for Climate Progress and my new Oxford University Press book coming out next week, “Climate Change: What Everyone Needs to Know.” This investigative report is built on dozens of studies and literature reviews as well as exclusive interviews with many of the world’s leading experts in public health and indoor air quality, including authors of both studies.

What scientists have discovered about the impact of elevated carbon dioxide levels on the brain

Significantly, the Harvard study confirms the findings of a little-publicized 2012 Lawrence Berkeley National Laboratory (LBNL) study, “Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance.” That study found “statistically significant and meaningful reductions in decision-making performance” in test subjects as CO2 levels rose from a baseline of 600 parts per million (ppm) to 1000 ppm and 2500 ppm.

Both the Harvard and LBNL studies made use of a sophisticated multi-variable assessment of human cognition used by a State University of New York (SUNY) Upstate Medical University team, led by Dr. Usha Satish. Both teams raised indoor CO2 levels while leaving all other factors constant. The findings of each team were published in the peer-reviewed open-access journal Environmental Health Perspectives put out by the National Institute of Environmental Health Sciences, a part of NIH.


Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance

Usha Satish et al.


    Background: Associations of higher indoor carbon dioxide (CO2) concentrations with impaired work performance, increased health symptoms, and poorer perceived air quality have been attributed to correlation of indoor CO2 with concentrations of other indoor air pollutants that are also influenced by rates of outdoor-air ventilation.

    Objectives: We assessed direct effects of increased CO2, within the range of indoor concentrations, on decision making.

    Methods: Twenty-two participants were exposed to CO2 at 600, 1,000, and 2,500 ppm in an office-like chamber, in six groups. Each group was exposed to these conditions in three 2.5-hr sessions, all on 1 day, with exposure order balanced across groups. At 600 ppm, CO2 came from outdoor air and participants’ respiration. Higher concentrations were achieved by injecting ultrapure CO2. Ventilation rate and temperature were constant. Under each condition, participants completed a computer-based test of decision-making performance as well as questionnaires on health symptoms and perceived air quality. Participants and the person administering the decision-making test were blinded to CO2 level. Data were analyzed with analysis of variance models.

    Results: Relative to 600 ppm, at 1,000 ppm CO2, moderate and statistically significant decrements occurred in six of nine scales of decision-making performance. At 2,500 ppm, large and statistically significant reductions occurred in seven scales of decision-making performance (raw score ratios, 0.06–0.56), but performance on the focused activity scale increased.

    Conclusions: Direct adverse effects of CO2 on human performance may be economically important and may limit energy-saving reductions in outdoor air ventilation per person in buildings. Confirmation of these findings is needed.

Environ Health Perspect; DOI:10.1289/ehp.1104789

Posted by John J. Ray (M.A.; Ph.D.).

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