slide presentation on global warming

Oct. 2010

Dr. Ingrid Nygaard 




The physicians and other scientists making this presentation today are members of the following organizations:  The Utah Physicians for a Healthy Environment, the faculty of the University of Utah Medical School, Utah State University and the Utah Medical Association.  We are here today out of concern that public health in Utah and our individual patients are being impacted by climate change and will be even more so in the future.   This adds an entirely new dimension to the urgency of addressing this evolving global crisis.




Recently the lead article in the Lancet, one of the world’s most prestigious medical journals, written by 29 distinguished medical scientists called the climate consequences of the greenhouse gas phenomenon, “The biggest global health threat of the 21st century,” and  Slide  will, “put the lives and wellbeing of billions of people at increased risk.”


The report goes on to state that, “Even the most conservative estimates are profoundly disturbing and demand action.  Less conservative climate scenarios are so catastrophic that adaptation might be unachievable.”   Slide The authors said that health professionals have come late to this debate, but what is needed now is a public health movement that frames the threat of the climate crisis for humankind as a health issue.  We intend to start that in the state of Utah today


Let me first outline our message today and then each person on the panel will give more details elaborating on these points of emphasis.




1.  The scientific organizations throughout the world in are in agreement, that we have entered into the early stages of a climate crisis, the driving force of which is primarily man made.   The scientific evidence for this is just as unassailable as the evidence that smoking causes cancer.


2.  The climate disturbances will include not just much hotter temperatures, but greater extremes of weather, especially drought and severe disruptions of the ecosystems that support the human population.  Utah will see average temperatures as much as 10 degrees hotter by 2100.


3.  Global public health consequences will be unprecedented, and threaten the lives and health of billions of people with as much as 30% of the world’s population becoming climate refugees.  Although poorer countries will be affected the most, no country will be spared and Utah will not be spared.


4.  World wide food production and food security are already under severe stress and almost certain to become much worse as the climate crisis deepens.  Utah will be secondarily affected by increased commodity prices and by climate caused geopolitical destabilization that our own federal intelligence agencies acknowledge represents the greatest future security threat to this country.


5.  These climate disturbances will have direct, predictable impacts on public health in Utah including:  more air pollution, more heated related illness, more frequent and intense dust storms, more vector borne and other infectious diseases, and more exposure to mercury contamination.


Lastly, we will talk about how Utahns should respond and offer specific recommendations for state government action.


Robert Davies, PhD


The Climate Science.


As Ingrid just noted, the fundamental premise underlying today’s event is the science of climate change.




If you’re among those confused by this science, it’s understandable. For one thing it’s complex.  But more importantly, the sheer volume of confusing and conflicting information pouring over us, every day is staggering.




Consequently the Utah physicians here today have asked me to help clarify the state of this science, for the record.  So let me begin with this: the following are the unequivocal conclusions of both the American and international climate science communities:




1.   Earth is warming — nearly 2 degrees F, global average, in the past 150 years, about half of that coming in the past fifty years.  While this might not sound like much, it’s a rate of warming about ten times greater than the rate lifting us from the last ice age, and a rate that’s expected to increase in the coming decades.

On this point of warming, there’s been considerable chatter in some corners of the media that Earth is actually cooling — that we haven’t warmed since 1998. This is confusing to many, and utterly wrong.  It’s a piece of misinformation that comes from a complete misunderstanding of the notion of climate.


Slide  Let’s take a look.  This graph shows global average temperatures for the past 150 years.  The last year—on the far right—is 2008. Two things are clear: the overall trend is definitely upward; and there’s a fair amount of year-to-year variability.  In other words, while the trend is up, not every year is hotter than the last.  It zigzags up.  But climate isn’t about short-term ups and downs, it’s about longer term averages.  And climate change is about longer-term trends. Slide So let’s look at this graph from the viewpoint of climate.  While it’s true that 2008 was definitely cooler than 1998 — the warmest year on record—the 2000-2008 average…here…Slide, is substantially warmer than 1990-1999 average…here Slide.   Roughly speaking, then, this is what the data looks like to climate scientists Slide.  Definitely. Not. Cooling.Slide


2. Slide Second, to a high level of scientific confidence, humans are now the single largest influence driving this change in global climate —at least ten times stronger than the next largest natural influence; perhaps as much as 30 times stronger.


3. Slide Third, the risks posed by this abrupt warming to humans, human society and the human ecosystem this century are very large and rapidly growing.


4. Slide Finally, the scientific consensus on these points is robust — as strong or stronger than the consensus linking cholesterol to heart disease; and earthquakes to plate tectonics.


Slide It would be my preference to take time to cover each of these conclusions in some detail.  Unfortunately, our time today is limited.


2. Warming and Cause


Slide Therefore, with respect to warming and cause, let me briefly say this:  the conclusions on warming and human cause are based on an overwhelming preponderance of evidence Slide.  Literally thousands of independent lines of evidence all consistent with a rapidly warming planet, attributable primarily to human activities — principally, the burning of fossil fuels, which adds heat-absorbing greenhouse gases to the atmosphere, and large-scale changes in land use, such as deforestation, which alter nature’s ability to remove these gases from the atmosphere. Slide




On these next two points—Slide projections of where our very best science tells us we’re headed; and the level of scientific consensus— I’ll spend a bit more time.


3. Projections




Slide To better understand the risks we’re facing, we need to examine where we’re headed, and place this in historical context.




[Slide—temp. scale] This temperature scale ranges from about 45 deg, the depth of the last ice age, to 75 deg, a global ave. temperature last seen on the planet over 50 million years ago.  Slide


This green oval covers the range of the human climate—this is the climate in which the modern human ecosystem evolved and has inhabited for it’s entire 200,000 year-existence.  Humans have never lived outside of this climate.


150 years ago, at the beginning of the industrial revolution in earnest Slide—57 deg], we sat just above 57 deg [Slide—+2 deg]; since then we’ve added about 2 degrees.


So that’s where we’ve been and where we are.  Where does the science say we’re going?


In 2007, the IPCC, using ensemble modeling results from nearly two dozen groups around the world,  projected between [Slide—’07 projections] 3 1/2 and 8 deg of warming by 2100—depicted here in red.




Unfortunately, the intervening two years have seen strong evidence suggesting changes are progressing bigger and faster.  More recent modeling work has revised these numbers substantially upward  [Slide—’09 projections] , to between 5 and 11 deg of warming by 2100.


From a climate science perspective, and a risk management perspective, these numbers are staggering.  [Slide]  As this graphic makes absolutely clear, even the most optimistic projections tell us that, unless we’re able to mitigate our impact on climate in the very near future, humanity will envelope itself in a climate substantially different from any we’ve ever known.


Further, it’s critical to note that not all places are being — or are expected to be affected equally.  [Slide] This graph depicts the same temperature data I showed you earlier, plotted slightly differently.  It’s the change in global ave. temperature over the past 100 years.


[Slide]  This graph shows the change that’s occurred in the U.S. West…


[Slide]  And this graph shows the change in the Colorado River Basin, including Utah — more than double the global average.


4. Consensus


How does one assess the consensus on this science?


First let me be clear, [Slide] I’m talking about scientific consensus—the kind that arises among the relevant scientific community, based on published, reproducible evidence.


Think of it this way: if a few thousand cardiologists agree your arteries are clogged, you’re not likely to care if a single cardiologist disagrees, and you’re certainly not going to care if your dermatologist disagrees, if a talk radio entertainer disagrees, or if the odd politician disagrees.




In order to assess scientific consensus then, one looks to the relevant scientific communities, as reflected through science’s large collection of formal scientific organizations.


[Slide]  To begin, the Intergovernmental Panel on Climate Change is the largest, most comprehensive scientific review panel ever assembled, on any topic.  It comprises thousands of scientists and has been examining the question of climate change for over twenty years.  In that time they’ve issued four reports, each more detailed and comprehensive than the last.


[Slide] Their most recent report—the Fourth Assessment Report—was issued in 2007.  The portion examining warming and cause  [Slide]  is over a thousand pages long, based on more than 6,300 published studies.


Their conclusions were these: (i) we’re warming; (ii) humans are the principle cause; and (iii) the risks to humans, human society and the human ecosystem are large and growing — all to a high level of scientific confidence.


In response to this report, an impressive collection of the world’s relevant scient

Written on January 2nd, 2012

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Utah Physicians for Healthy Environment