See the Tabbed Pages for links to video tutorials, and a linked list of post titles grouped by topic.

This blog is expressly directed to readers who do not have strong training or backgrounds in science, with the intent of helping them grasp the underpinnings of this important issue. I'm going to present an ongoing series of posts that will develop various aspects of the science of global warming, its causes and possible methods for minimizing its advance and overcoming at least partially its detrimental effects.

Each post will begin with a capsule summary. It will then proceed with captioned sections to amplify and justify the statements and conclusions of the summary. I'll present images and tables where helpful to develop a point, since "a picture is worth a thousand words".

Wednesday, December 18, 2019

“U.N. Climate Talks End With Few Commitments and a ‘Lost’ Opportunity”

“U.N. Climate Talks End With Few Commitments and a ‘Lost’ Opportunity” is the heading in the New York Times, December 15, 2019, reporting on the largely failed conclusion to the annual UN climate conference held in Madrid, Spain.  Recent annual meetings are follow-ups to the conference in Paris four years earlier, which produced the 2015 Paris Agreement on reducing greenhouse gas (GHG) emissions.  It was agreed to by the almost 200 member nations of the UN, and has the goal of keeping the increase in the long-term global average temperature below 2°C (3.6°F) above the pre-industrial temperature.  It also included the hope that the limit could be more stringent, keeping the increase below 1.5°C.

The Agreement is intended to minimize further global warming and the resulting harms to the world’s climate.  Warming arises because the growth in the world’s economies in the last 1½-2 centuries has relied largely on energy derived by burning carbon-containing fuels (fossil fuels: coal, petroleum and natural gas) that release carbon dioxide (CO2; a GHG) when burned.  The added CO2 accumulates in the atmosphere and remains there for centuries, producing increased temperatures by an atmospheric greenhouse effect.  China’s dramatic economic growth over the past 3 decades, for example, closely parallels its growth in use of fossil fuels and other energy sources.
The nations of the UN signed on to the Paris Agreement because, in contrast to the earlier Kyoto Protocol, each nation’s contribution to reducing emissions is voluntary.  Analysis of those contributions at the time (Fawcett and coworkers, 2015) already showed, however, that they were inadequate to produce the GHG reductions needed to stay within the 2°C limit.
One objective at the Madrid 2019 gathering was for the nations to generate more ambitious goals to reduce GHG emission rates that would lead to compliance with the Paris Agreement limit.  Recently the U. S. under President Trump has stated its intention to withdraw entirely from the Agreement, to take effect just before the next meeting in 2020.  As the New York Times reports, for this reason “…it was the last chance, at least for some time, for [America to negotiate] — and perhaps a turning point in global climate negotiations, given the influence that Washington has long wielded…in the discussions.” 
But the U. S. was not alone in hindering progress. Helen Mountford, a vice president at World Resources Institute, said “[m]ost of the large emitters were missing in action or obstructive.”  Nations with significant rates of GHG emissions, including China and India, “balked at suggestions of more ambitious climate targets next year.”
Ms. Mountford further lamented that the failure to act in Madrid “reflects how disconnected many national leaders are from the urgency of the science and the demands of their citizens.”
“The urgency of the science” is apparent in reviews of the worsening warming and climate appearing in rapid succession in the past year.  The Intergovernmental Panel on Climate Change (IPCC) issued its report , “Global warming of 1.5°C - - An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty” in October 2018.  The IPCC reports that in the three years since the Paris Agreement, atmospheric GHG content and temperatures were rising faster than foreseen earlier.  Therefore it feels we must bring worldwide GHG emissions to near zero by about 2040, earlier than recommended in previous reviews.
The Arctic is warming twice as fast as elsewhere on Earth, the National Oceanic and Atmospheric Administration reported in December 2019. This finding has significance throughout the world, because the warmer temperatures are now melting the Greenland Ice Sheet very rapidly.  In the 1990’s melting ice was roughly balanced by new precipitation.  But by the 2010’s net loss of ice occurred due both to excessive surface melting and faster glacier calving.  Overall, ice loss from Greenland alone contributed 10 mm (0.4 in) to global sea level rise in this period.
Oceans absorb about 90% of the excess heat retained by the earth, by transfer of the heat from the atmosphere to the water.  This heating has accelerated in recent years.  Water expands as it warms, contributing an additional amount to sea level rise.  Changing temperatures in the oceans have led to coral die-offs (some of which is not recovered), and to changes in the species distribution of sea animals because they are exquisitely sensitive to the ocean temperature.  This impacts human fishing productivity.  Warm water also evaporates more moisture into the air, making hurricanes more violent and releasing more rainfall, as has been observed in recent years.
“The demands of [nations’] citizens” have grown more insistent in the past year.  The teenage climate activist Greta Thunberg, recently named TIME magazine’s Person of the Year, has stimulated a worldwide climate movement among youth, and adults.  Our children understand that they will experience the climate extremes resulting from adults’ climate inaction.  The Madrid meeting shows that the world’s resolve meaningfully to combat global warming and climate change appears compromised by the absence of international political will, presumably abetted by economic factors and fossil fuel commercial interests. 
But optimism persists nevertheless.  As Ms. Thunberg concluded in her speech to Madrid attendees, “[T]here is hope….It does not come from the government or corporations.  It comes from the people….People are ready for change….Every great change …come[s] from the people.”

© 2019 Henry Auer

Friday, December 13, 2019

From Lone Climate Protester to A Worldwide Movement: Greta Thunberg

On Dec. 11, 2019 TIME magazine named Greta Thunberg, the 16-year old Swedish climate activist, its Person of the Year.  A little more than one year ago (i.e. at age 15) she felt sufficiently worried

about the effects that climate change was wreaking that she felt she needed to take action.  She began once-weekly stints of abandoning her school and sitting, alone, in front of the Swedish Parliament building in Stockholm with a sign reading “Student Climate Strike”.
After a few weeks others, especially youth, took up her cause and the numbers grew to the tens, and soon became an international movement.  By December 2018 she had gained sufficient renown to address the 24th annual United Nations climate conference in Katowice, Poland.  (The 21st conference is the one that produced the Paris Climate Agreement in 2015).  This writer transcribed passages from her address, shown in this graphic and below:

Screenshot:; Image by Henry E. Auer

“You [adults] are not mature enough to tell it like it is.  Even that burden you leave to us children ….In 2078 I will celebrate my 75th birthday.  [Maybe my children] will ask me about you.  Maybe they will ask why you didn’t do anything while there still was time to act….We  cannot solve the crisis without treating it as a crisis….We have run out of excuses and we are running out of time.”

Since then, Ms. Thunberg has galvanized an entirely new climate movement, comprised largely of youth.  The power of her message led to worldwide climate demonstrations on Sept. 20, 2019, and to speaking to the U.N. General Assembly on Sept. 23.  Most recently, after sailing to and from the U. S. without fossil fuels, on a boat equipped with solar panels, she spoke at the 25th U.N. climate conference in Madrid, Spain on Dec. 11, 2019 (her speech beginning at about 16:00 min. at the linked video).  This was only moments before TIME announced honoring her as Person of the Year.  Here are excerpts from her speech, transcribed and edited by this writer.

“…For about a year, I have been talking about our rapidly declining carbon budget….  But …this is still being ignored….[T]he SR 1.5 IPCC Report [Special 1.5°C Report, from the  Intergovernmental Panel on Climate Change] that came out last year [says] if we are to …[limit] the temperature rise [since the industrial revolution began] to below 1.5°C we had, on Jan. 1, 2018, 420 gigatonnes [gT, billions of metric tons] of CO2 left [to emit into the atmosphere]….  And of course that number is much lower today [2 years later] as we emit about 42 gT every year….[T]hat remaining budget will be gone within about 8 years…
“…[T]hese figures…do not say anything about the aspect of equity, which is absolutely essential to make the Paris Agreement work…[applause].  That means that richer countries need to…get down to…zero emissions much faster, then help poorer countries do the same, so that [they] can raise their living standards….
“How do you react to these numbers without feeling…some…panic?  How do you respond to the fact that nothing is being done about this without feeling anger? And …without sounding alarmist?....
“Recently [some] countries pledged to reduce … emissions … by so and so many percent by this or that date….This may sound impressive …, but… this is not leadership…this is misleading….These pledges don’t include the immediate yearly reduction rates needed…to stay within the remaining tiny [carbon] budget…
“Finding holistic solutions is what [this 25th meeting] should be all about.  But instead, it [becomes] an opportunity for countries to negotiate loopholes and raise their emissions [applause]….
“This has to stop.  What we need is real drastic emission cuts….[They have] to stop….We need to keep the carbon in the ground….[T]he changes required are nowhere in sight.  The politics needed do not exist today….[T]he real danger is when politicians and CEOs are making it look like real action is happening, when in fact almost nothing is being done apart from clever accounting and creative PR [applause]….
“[T]here is hope….It does not come from the government or corporations.  It comes from the people….People are ready for change….Every great change …come[s] from the people.”

Greta Thunberg has mobilized youth (and adults) because her generation, born in the years just following the dawn of the new millennium, is the first destined to experience the full brunt of the climate crisis foreseen in climate models that typically extend from the present to the end of this century. Their lifetimes will extend throughout most or all of this span.  These reports include the IPCC Special Report-Global Warming of 1.5 ºC   referred to by Ms. Thunberg, and the U. S. Fourth National Climate Assessment, among many others.
Climate harms are already fully apparent throughout the world on almost a daily basis in news reports in the last few years.  These include unprecedented heat and drought, resulting shrinkage and loss of water resources, extensive and terrifying wildfires in both virgin woodlands and inhabited regions, extreme precipitation leading to freshwater flooding, agricultural lands removed from routine production due to excessive flooding, progressive sea level rise, and extreme tropical storms that are larger and longer-lasting than in the past, and extreme shoreline storm surges.  Unchecked warming of the earth’s atmosphere is modeled to make these harms and damages even more severe than currently experienced.  These predicted harms constitute a true climate crisis. 
These are the reasons we must heed our youth activists; our actions can help achieve the climate mitigation steps needed for their lifetime wellbeing.  The IPCC Special Report-Global Warming of 1.5 ºC makes clear that drastic reductions in greenhouse gas emission rates must be fully under way by about 2030 and those rates reduced to near zero by about 2040.  As Ms. Thunberg signals, the Special Report specifies that our remaining carbon budget is rapidly dwindling.

 © 2019 Henry Auer

Friday, July 12, 2019

We All Feel the Increasing Impacts of Global Warming

Summary: All over the world unprecedented weather extremes are occurring, with profound effects on human activities and health.  This post reports some recent climate events.  These instances are consistent with the forecasts that climate scientists have been making for several decades.  The IPCC issued a new, more urgent report in October 2018 specifying that we have to keep the world temperature increase below 1.5°C above pre-industrial levels, primarily by eliminating all emissions worldwide in about two decades.


Tidal flooding, Eastern U. S.  Many cities along the Eastern seacoast of the U. S. already suffer fair-weather tidal flooding due to rising sea levels.  According to the U. S. National Oceanic and Atmospheric Administration (NOAA) as reported by National Public Radio (NPR), tidal flooding is worsening in more than 40 U. S. coastal cities.  Most of these flood days are not related to storm activity, but rather to rising sea level.  Tides are worst, i.e., highest, when the moon is full or new.  This image

Source: NPR All Things Considered

shows downtown Annapolis, MD, founded three centuries ago on the shores of Chesapeake Bay, flooded during a high tide in 2017.  As NPR reports, NOAA finds that tidal flooding events in Annapolis have increased by 925% over the last 50 years.  The city is planning a Flood Mitigation Project in conjunction with many agencies including the U. S. Naval Academy, which is located in Annapolis.

Charleston, SC is also suffering from worsening ocean flooding (NPR).  The city is built on a low-lying peninsula, exposed to the sea.  In addition, in recent years flooding has been aggravated by extreme rainfall.  Both of these factors result from worsening global warming.  The city issues flood warnings as frequently as weekly during the summer.  Its officials now understand they must plan for 2-3 feet (0.6-0.9 m) of flooding over the next 50 years.

Temperatures for January-May 2019 for most regions around the globe are warmer than average or set warmest records, whereas only a very few regions were cooler than average (see the following image).

Source: NOAA National Centers for Environmental Information, State of the Climate: Global Climate Report for May 2019, published online June 2019, retrieved on July 10, 2019; .

The average is for the 30-year reference period from 1981-2010.  It is seen that for the vast majority of global surface pixels the 5-month averages were mildly or much warmer than the 30-year reference period.  In an accompanying graphic NOAA shows land and ocean temperature departures from the 30 year reference period for the January-May interval annually from 1880 to the present (not shown).  Starting about 1976 the departures are all only positive, trending up to 0.8-1.1°C (1.4-2.1°F) above the average between 2015 and 2019.  The full 139-year record shows clearly that, although there are year-to-year variations, the long-term trend in the 5-month global average temperature has been gradually increasing by about 1.3°C (2.3°F) starting at about 1910.

Global warming has been determined to have caused two current climate extremes.  First, a severe heat wave blanketed much of western Europe during the end of June 2019.  It broke heat records across much of the area.  A group of experts in the field of climate attribution examined the temperature data in two ways, as described in a commentary in the journal Nature. 

Attribution science has made great strides in recent years.  In this case, the scientists examined the heat wave in two ways.  First, they compared the actual temperature record with results from climate models for the European region, running cases that included or excluded a man-made greenhouse effect.  They found that the record heat was five times more likely with extra greenhouse gases than without.  Second, they assessed whether historical records going back 100 years are consistent with the actual heat wave data when climate models are used to “hindcast” the data.  They found that global warming and air pollution made the current heat wave 100 times more likely than without those factors. 

More generally, the commentary summarizes that about two-thirds of the 200 attribution inquiries reported to date have positively identified global warming as making the particular event being studied more likely or more severe than without warming.

Second, a report from India describes “Zero Day, the day when a city’s taps dry out and people have to stand in line to collect a daily quota of water.”  This is currently happening in many Indian states because aquifers are being over-drawn and this year’s monsoon rains were 30% less abundant than usual.  The image below exemplifies the disaster:

Zero Day has already occurred in the city of Chennai, and is predicted to happen next year in many cities, including the capital, Delhi.  In all 600 million people may be impacted.  Groundwater is the source for most of India’s rural inhabitants and for its agriculture.  The Ministry of Drinking Water and Sanitation states that global warming is one factor contributing to this crisis.
The Paris Agreement of December 2015 pledged 193 members of the United Nations voluntarily to reduce greenhouse gas emission rates sufficiently to keep the planet below a 2°C rise above pre-industrial levels by 2100.  But the Agreement is failing; the rate of emissions is still increasing, raising the total accumulated greenhouse gas burden of the atmosphere.  As a result, the IPCC issued a new, more drastic report in October 2018 specifying that we have to keep that temperature increase below 1.5°C, and to reach a worldwide reduction of emission rates to zero by about 2040, or 21 years from now. 

Failing to achieve this goal will lead to more intense warming, and will contribute to more rapid sea level rise, impacting coastal cities around the world, as discussed above.  It will also contribute to the more intense extremes of heat, such as Europe has experienced, as well as more extreme heat and aridity such as India is experiencing.

The economic harm alone is problematic, since in general our political structures don’t budget for funds to revive the losses, and insurance may be inadequate or nonexistent.  All people of the world have to mobilize individually and politically to eliminate fossil fuel use and develop a renewable energy economy to achieve the goal of zero emissions.

© 2019 Henry Auer