August 30, 2018
 
Dear Friends and Family,
 
Segment 13 is the last segment in the Climate Change Series.  Up to this point in the series we have utilized excerpts from seven books supporting a skeptical view of fossil fuel induced climate change and five books that support an advocate view.  To level out the volume of excerpts between the two positions, this last segment will only contain excerpts from the advocate persuasion.  As you read the excerpts, I would encourage you to note whether you agree or disagree with each aspect presented based on what you learned and retained from the first 12 segments.  This may help you to solidify your position on the debate, if you have not already done so previously 
 
The text for the excerpts in this segment all come from Climate Change What Everyone Needs to Know by Joseph Romm.  Dr. Romm’s bio found on the back cover of the book reads as follows: “Dr. Joseph Romm is one of the country’s most influential communicators on climate science and solutions.  He is the Chief Science advisor for “Years of Living Dangerously,” which won the 2014 Emmy Award for Outstanding Non-Fiction Series and founding editor of the blog “Climate Progress” which New York Times columnist Tom Friedman called indispensable.  In 2009, Time named Romm one of its Hero’s of the Environment and the Web’s most influential climate change blogger.  Rolling Stone named him one of 2009’s “100 people who are reinventing America.”  Romm was acting assistant secretary of energy in 1997, overseeing $1 billion in low-carbon technology development.  He holds a PhD. In physics from MIT. 
 
There is no PDF attachment with an expanded (unabbreviated) set of excepts for this segment.  I hope you have found this learning as worthwhile as I have, and that it helped you formulate, solidify, or change which side of the debate you have concluded is correct. 
 
Happy Learning,
Harley

---

CLIMATE CHANGE – SEGMENT 13
THE FINAL ADVOCATE WORD

NOTE:  All of the excerpts in this segment are from Climate Change What Everyone Needs to Know (2016) by Joseph Romm
INTRODUCTION
Climate change is now an existential issue for humanity.  Serious climate impacts have been observed on every continent.  Far more dangerous climate impacts are inevitable without much stronger action than the world is currently pursuing, as several major 2014 scientific reports concluded. 

Will we stay on our current path and trigger amplifying feedbacks that cause further warming, pushing us closer to irreversible tipping points. Or will we instead act quickly enough to avoid the very worst impacts?  Leading scientists and governments say that would mean keeping total warming as close to 2 degrees C (3.6 degrees F) as possible and preferably below it.  Meeting such a warming target would require all nations to replace fossil fuels with clean energy at an even faster rate than we are currently planning – and for total global carbon dioxide emissions to be zero (or negative) by century’s end. 
This book will not enter into the unproductive political debate over the science.  Rather, it takes as a starting point the overwhelming consensus of our top global experts and governments, as laid out in the recent Intergovernmental Panel on Climate Change summary reviews of the literature, culminating with the November 2014 “Synthesis Report.”  The 2014 Report issued their bluntest statement yet to the world:  Cut carbon pollution sharply starting now (at a very low cost) or risk “severe, pervasive and irreversible impacts for people and ecosystems.” 

CLIMATE SCIENCE
The latest science finds that all of the warming since 1970 is due to human causes.  In September 2013, the United Nations Intergovernmental Panel on Climate Change (IPCC) released the first part of its Fifth Assessment Report, a summary report of the scientific literature.  That summary was approved line-by-line by the governments representing the overwhelming majority of the Earth’s population.  The Panel concluded, “The best estimate of the human-induced contribution to warming is similar to the observed warming over this period” from 1951 to 2010.  In other words, the best estimate is that humans are responsible for all of the warming we have experienced since 1950. 
​
Studies reveal that some 97 of 100 actively publishing climate scientists agree with the overwhelming evidence that humans are causing global warming.  That report described the scientific consensus this way.

The science linking human activities to climate change is analogous to the science linking smoking to lung and cardiovascular diseases.  Physicians, cardiovascular scientists, public health experts and others all agree smoking causes cancer.  And this consensus among the health community has convinced most Americans that the health risks from smoking are real.  A similar consensus now exists among climate scientists, a consensus that maintains climate change is happening, and human activity is the cause.

The long-term historical record indicates that after some forcing event starts the warming process, amplifying feedbacks in climate systems reinforce that warming, which causes the warming to speed up.  The paleoclimate record suggests that the initial forcing could be a release of greenhouse gases or a change in Earth’s orbit that brings more intense sunshine to parts of the planet. 

One important amplifying feedback occurs because, as the planet warms, the extent of both sea ice and land-based ice (glaciers) shrinks.  Thus, white ice, which is very reflective, is replaced by the blue sea or dark land, each of which absorb much more solar radiation.  The blue oceans and dark earth also heat up much faster than ice would, which results in even more ice melting.  This feedback causes a big decrease in the Earth’s overall reflectivity, which in turn leads to more warming and a rapid rise in temperatures, especially in Polar regions.  This crucial fast feedback, which is part of a process called polar amplification, is now occurring in the Arctic, and it has caused the Arctic region to warm at twice the rate of the planet as a whole.  It is the central reason we have seen an almost 80% drop in late summer Arctic ice volume since 1979 and a more than five-fold increase in the Greenland ice sheet melt rate in the past two decades.

Another key rapidly acting amplifying feedback is driven by water vapor.  As the planet starts to heat up, evaporation increases, which puts more water vapor into the air.  Water vapor is a potent heat-trapping greenhouse gas.  So, an increase in water vapor causes an increase in warming which causes an increase in water vapor, and so on. A 2008 paper analyzing recent changes in surface temperature and the response of lower atmosphere water vapor to these changes concluded: “water-vapor feedback implied by these observations is strongly positive” and “similar to that simulated by climate models.”  The lead author, Professor Andrew Dessler, a climatologist at the Department of Atmospheric Sciences of Texas A&M University, has said that this finding is “unequivocal.”  That analysis concluded:

The existence of a strong and positive water-vapor feedback means that projected business-as-usual greenhouse-gas emissions over the next century are virtually guaranteed to produce warming of several degree Celsius.  The only way that will not happen is if a strong, negative, and currently unknown feedback is discovered somewhere in our climate system.

The latest science suggests that we are getting close to levels of greenhouse gases in the atmosphere that will trigger irreversible changes, and, in at least one case, we may have already crossed a tipping point.  In 2009, a team of researchers led by National Oceanic and Atmospheric Administration (NOAA) scientists published a major study that concluded: “the climate change that is taking place because of increases in CO2 concentration is largely irreversible for 1,000 years after emissions stop.”  This NOAA-led study found that some of the most severe long-term impacts, such as drops in precipitation and unstoppable sea level rise, would become irreversible this century if CO2 levels continue to rise as they have because of human activity.  We are now near 400 ppm and rising more than 2 ppm a year.  We are headed to CO2 levels above 600 ppm this century on our current emissions trajectory.  A key point is that irreversible does not mean unstoppable, especially if we can deep total warming below 2 degrees C (3.6 degrees F) which is roughly an atmospheric concentration of CO2 of 450 ppm.

EXTREME WEATHER
Droughts:  Global warming causes greater evaporation and, once the ground is dried out, the Sun’s energy goes into baking the soil, leading to a further increase in air temperature.  That is why, for instance, so many temperature records were set for the United States in the 1930s Dust Bowl, and why, in 2011, drought-stricken Oklahoma saw the hottest summer ever recorded for a U.S. state.  Climatologist Keven Trenberth quantified the impact of human caused warming this way in an email: “The extra heat from the increase in heat trapping gases in the atmosphere over six months is equivalent to running a small microwave over at full power for about half an hour over every square foot of land under drought.”

Water Supply:  Although dramatic reductions in precipitation are the major driver of record droughts, hot weather droughts are considerably worse for humans, animals, and crops that cooler weather droughts.  When it’s hotter, you also have a “greater ratio of rain-to-snow” and “faster melting of snow,” both of which dramatically reduce the snowpack that is such a critical reservoir for California and the West during the dry summer months.  Many regions are already seeing (1) a larger proportion of their precipitation in the form of rain than snow and (2) earlier snowmelt.  A 2011 U.S. Geological Survey study found that global warming was driving a snowpack loss in the Rocky Mountains unrivaled in 800 years, which in turn was threatening the region’s water supply.

Wildfires:  Global warming makes wildfires more likely and more destructive – as many scientific studies have concluded.  Why?  Global warming leads to more intense droughts, hotter weather, and earlier snowmelt (hence less water available for late summer and early autumn).  That means wildfires are a dangerous amplifying feedback, whereby global warming causes more wildfires, which release CO2, thereby accelerating global warming.

Storms:  Global warming has been observed to make the most intense rainstorms more intense.  A key reason is the extra water vapor in the atmosphere from warming.  This means that when it is cold enough to snow storms will be fueled by more water vapor and thus be more intense themselves.  Therefore, we expect fewer snowstorms in regions close to the rain-snow line, such as the central United States, although the snowstorms that do occur in those areas are likely to be more intense. 

Storm Surge:  The most direct way that climate change affects storm surge is by raising sea levels.  As the average sea-level rises, storm surges on average will also rise, even if the storms themselves do not become more intense.  Studies also suggest that the global warming is driving an increase in the some of the most intense and damaging superstorms, which would further boost storm surge for those storms beyond the average rise in sea levels. 

Hurricanes:  The best evidence and analysis finds that although we are not seeing more hurricanes, we are seeing more of the Category 4 or 5 super-hurricanes, the ones that historically have done the most damage and that have destroyed entire coastal cities.  At the same time, we are seeing a significant rise in the most damaging storm surges, whereby even a Category 1 hurricane that hits in precisely the worst possible place can cause unprecedented damage to coastal communities and major cities. 
​
PROJECTED CLIMATE IMPACTS
General:  The recent scientific literature warns us that we face multiple severe impacts in the coming decades if the world stays near our current greenhouse gas emissions path.  These impacts include the following:

• Very high temperature rise, especially over land
• Worsening Dust Bowl conditions over the U.S. Southwest, Southern Europe and many other regions around the globe that are heavily populated and/or farmed.
• Sea level rise of up to 1 foot by 2050, and 4 to 6 feet (or more) by 2100, rising as much as 12 inches or more each decade thereafter.
• Massive species loss on land and sea
• Much more extreme weather
• Food insecurity – the increasing difficulty of feeding 7 billion, then 8 billion, and then 9 billion people in a world with an increasingly inhospitable climate
• Myriad direct and indirect health impacts

One of the biggest sources of confusion in climate discussion involves the question of how much warming humanity will experience this century and what are the sources of uncertainty in that projection.  Based on our current greenhouse gas trajectory and the best estimate of how sensitive the climate is to greenhouse gas levels in the atmosphere, 4 degrees C (7 degrees F) total warming by 2100 (or shortly thereafter) is a reasonable projection.  There is considerable uncertainty in that number, although unfortunately, most of the uncertainty involves the possibility of even greater warming.  Since people who live in the mid-latitudes (like most Americans and most Europeans) are projected to warm considerably more than the global average.  Therefore, if the planet as a whole, warms 4 degrees C, (7 degrees F), much of the global population faces warming of 5 degrees C (9 degrees F) or more.

Sea Level Rise:  What science has told us in 2014 and 2015 about likely sea level rise this century and beyond has been shocking.  The IPCC assumed most sea-level rise will come from thermal expansion of the ocean and melting of inland glaciers around the world.  They assumed the Greenland Ice Sheet makes at most a modest contribution.  The panel acknowledges, however, that it really has no idea what the ice sheets could do:  "The basis for higher projections of global mean sea-level rise in the 21st century has been considered and it has been concluded that there is currently insufficient evidence to evaluate the probability of specific level above the assessed likely range.

The recent findings have led top climatologists to conclude that we are likely headed toward what used to be the high-end of projected global sea-level rise this century (I.e. 4 to 5 feet) and that the worst-case scenarios where humanity fails take aggressive action to cut greenhouse gas emissions are considerably higher than that.  Such sea level rise would have severe direct consequences on coastal populations. One 2015 study found that by 2060, population in the low-elevation coastal zone – below 10 meters above sea level – could hit 1.3 billion people, which is twice current levels.  With even a relatively modest sea-level rise of 21 centimeters (8 inches) by then, more than 400 million people could be in the flood plain of the one-in-a-100-year storm surge. It is clear that sea-level rise post-2050 could be considerably higher than that, upwards of 10 feet by 2100.  So, it seems very likely that hundreds of millions of people will need to relocate this century just from sea-level rise and threat of storm surge only.  Harold Wanless, chair of University of Miami's geological sciences department said, "I cannot envision southeastern Florida having many people at the end of this century."  In 2014, he said, "Miami, as we know it today, is doomed.  It's not a question of if.  It's a question of when." 

Superstorms:  All future coastal superstorms will be operating in an environment with increasingly higher sea levels.  This means storm surges will get worse and worse.  Put another way, a much weaker storm than Hurricane Sandy will cause comparable damage when sea levels are a few feet higher.  The kind of sea-level rise we appear to be headed toward will make Sandy-type storm surges commonplace events on the East Coast after mid-century. 

Droughts:  As much as one third of the Earth's currently habited and arable land faces a near-permanent drying this century, according to several recent studies.  The 1930s Dust Bowl seems to be the best analogy to what is coming.  However, the coming multidecadal mega-droughts will be much worse than the Dust Bowl of the 1930s --"worse than anything seen during the last 2000 years," a major 2014 Cornell-led study put it.  They will be the kind of mega-droughts that in the past destroyed entire civilizations. Such Dust-Bowlification would be one of the most consequential impacts of climate change for the world.

Health:  If humanity stays near its current path of greenhouse gas emissions, the IPCC warns with "high confidence" that "the combination of high temperature and humidity in some areas for parts of the year is projected to compromise normal human activities, including growing food or working outdoors."  In that case, simply being outdoors in summer months will be unhealthy, and those areas of the world would increasingly be seen as uninhabitable. 

The report, "Managing the Health Effects of Climate Change," concluded, "Climate change is the biggest global health threat of the 21st century."  I warned, "Climate change will have devastating consequences for human health from."

• Changing patterns of infections and insect-borne diseases and increase deaths due to heat waves. 
• Reduced water and food security, leading to malnutrition and diarrhoeal disease
• An increase in the frequency and magnitude of extreme climate events (hurricanes, cyclones, storm surges) causing flooding and direct injury
• Increasing vulnerability for those living in urban slums and where shelter and human settlements are poor
• Large-scale population migration and the likelihood of civil unrest.

A 2011 editorial in The British Medical Journal, warned "Climate change poses an immediate and grave threat, driving ill health and increasing the risk of conflict, such that each feed on the other."  The threat posed by climate change to regional security "will limit access to food, safe water, power, sanitation, and health services and drive mass migration and competition for remaining resources."  There will be a rise in starvation, diarrhea, and infectious diseases as well as in the death rate of children and adults.

Agriculture:  Feeding 9 billion or more people mid-century and beyond in the face of a rapidly worsening climate is likely to prove the greatest challenge the human race has ever faced.  We are looking at the perfect storm of impacts.  Dust-bowl conditions are projected to become the norm for large areas in both food-importing and good-exporting countries.  This will be happening during a time when we will have drained many of the key aquifers that sustain agriculture in countries as diverse as India, China, and the United States.  In addition, the glaciers that act as reservoirs for major river systems will be shrinking and vanishing, further reducing water availability during the crucial summer season for crops. 

Every part of the world will be routinely hit by extreme deluges, floods, droughts, and heat waves that damage crops.  At the same time, salt water intrusion from sea level rise threatens some of the richest agricultural deltas in the world, such as those of the Nile and the Ganges.  Meanwhile, ocean acidification combined with ocean warming and overfishing may severely deplete the food available from the sea.

Violent Conflicts:   Climate change will "increase risks of violent conflicts in the form of civil war and inter-group violence.  That was a key summary conclusion of what the scientific literature says about climate "Impacts, Adaptation, and Vulnerability," IPCC reported in 2014.  A landmark study from 2015 says climate change has done just that in Syria.  And a 2014, a U.S. Department of Defense study concluded, "Climate change … poses immediate risks to U.S. national security," has impacts that can "intensify the challenges of global instability, hunger, poverty, and conflict" and will probably lead to "food and water shortages, pandemic disease, disputes over refugees and resources." 

In fact, climate change already appears to be driving and interacting with violent conflict.  A 2015 study found that human-caused climate change was a major trigger of Syria's brutal civil war.  The war that helped drive the rise of the terrorist Islamic State of Iraq and Greater Syria (ISIS) was itself spawned in large part by what one expert called perhaps "the worst long-term drought and most severe set of crop failures since agricultural civilizations began in the Fertile Crescent," from 2006 to 2010.  That drought destroyed the livelihood of 800,000 people according to the U.N. and sent vastly more into poverty.

Because conflict has many contributing causes and typically requires some sort of political trigger, predicting exactly when we might see more conflict by climate change is difficult to do.  In 2008, Thomas Fingar, the "the U.S. intelligence community's top analyst," estimates that it will happen by the mid-2020s, as "droughts, food shortages and scarcity of water will plague large swaths of the globe, from northern China to the Horn of Africa."  This "will trigger mass migrations and political upheaval in many parts of the developing world.  
​
Conclusion:  The scientific literature has made it increasingly clear that key impacts are irreversible on a time scale of centuries and possibly millennia.  This means that climate change creates risks that are unparalleled in human history.  It also means that if we follow the traditional way of dealing with an environmental problem, that is, wait until the consequences are obvious and unmistakable to everybody, it will be "too late" to undo those consequences for a long, long time.  
 
There is no unabbreviated version for the above.