We Can No Longer Delay Minimizing Global Warming/Climate Change

Summary: The Intergovernmental Panel on Climate Change has issued six Assessment Reports over the past three decades.  This blog has presented three posts recently tabulating the effects of warming and the scientific need for reducing greenhouse gas (GHG) emissions that the Reports presented.  The posts focus on the unabated increase in man-made carbon dioxide emissions, the consequent increase in global average temperature, and the inexorable increase in sea level.  For each of these topics, from the beginning the Reports have declared the necessity of minimizing GHG emissions in order to avoid the worst harms and damages from continued warming.  Their warnings have become more urgent, and have been expressed with increasingly unambiguous certainty, as the series of Reports has been issued.

Harms and damages that were only hypothetical in the early Reports have now become commonplace, as sea levels have continued rising; droughts, famine and wildfires have ensued; and more intense, violent climate and weather events have unfolded with freakish intensity.  Even so, policymakers and commercial interests in the private realm have largely ignored these warnings throughout the three decades.  Now is the time energetically to combat further warming globally to make up for three decades of inaction, and to mitigate worsening climate change.  We have no alternative.

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Introduction – The Urgent Need to Minimize Greenhouse Gas (GHG) Emissions.  In three recent posts this blog has summarized aspects of the work of climate scientists over the last 30 years.  The first post is titled “What,Again? Greenhouse Gases Accumulate in the Atmosphere”, the second is “What, Again? Global Warming Continues Unabated”, and the third is “What, Again? Sea Level Will Continue Rising for Centuries”.

Each post summarizes the aspect of climate science reflected in its title, as presented by the U. N.’s Intergovernmental Panel on Climate Change (IPCC) in its series of six Assessment Reports (ARs) issued over the past 31 years up to the (first of three volumes of) the Sixth AR, which appeared in August 2021. Each post included a tabulation of the significant findings, and the suggested future policies, related to the title of the post, as found in each AR.  Significantly, the need to reduce GHG emissions was already expressed in the first AR in 1990 and has been reinforced in each report up to the present time in the Sixth AR.  What has changed is that the strength of the climate science underpinning those conclusions has increased dramatically over time.  The capabilities of gathering data and using more powerful computers to analyze them, and to develop more refined, detailed climate models, have all increased remarkably.

Sadly, the world’s policymakers and industries have not heeded these warnings, but have continued policies and practices leading to unabated, indeed increasing, GHGs emissions throughout these three decades, as shown in the graphic below.

 

 

Direct measurements of atmospheric carbon dioxide (smoothed over the 12 months of a year) taken atop the Mauna Loa volcano in Hawaii beginning in 1958.  The base level prior to the Industrial Revolution is 280 ppm.  Ppm, parts of carbon dioxide in 1 million parts of air. The vertical lines represent the dates of issue of the respective Assessment Reports, and the date of the U. N. Paris Climate Agreement (2015).    Adapted from the carbon dioxide data referenced in the URL at the bottom of the image.

 

In spite of the persistent urgings of the six teams of climate scientists writing the six ARs over three decades, and the agreement reached in Paris among virtually all GHG-emitting nations to begin reducing their emissions, the data in the graphic show no indication of slowing emission rates up to the present time.

Accumulated GHGs are directly responsible for increasing global temperatures.  Many man-made GHGs, including the extra carbon dioxide emitted by burning fossil fuels, are “long-lived” GHGs.  Once emitted into the atmosphere they remain there for hundreds or thousands of years without being destroyed or taken up by the earth system, so that they accumulate to ever higher levels with each passing year.  (A minor fraction of carbon dioxide is absorbed by photosynthesis and by dissolving into oceans and lakes.)  That is why the image above shows that carbon dioxide levels in the atmosphere keep increasing.  The increase from one year to the next represents the net amount added to the atmosphere during that year.  Indeed, the carbon dioxide level increased from about 353 ppm at the time of the First AR to about 416 ppm at the Sixth AR, the present.

Greenhouse gases are called that because they retain a portion of the sun’s energy reaching the earth as heat energy, instead of having that heat be radiated from earth back into outer space.  This leads the temperature of the earth system to increase. The earth system mimics glass greenhouses in retaining heat.  Their glass enclosure captures outgoing heat energy, so that excess heat accumulates inside the greenhouse.  The interiors of cars in the summer sun heat up for the same reason.  Climate modeling of future warming, summarized in recent ARs, shows that the extent of incremental heating of the earth system depends on excess GHGs in the atmosphere (including excess carbon dioxide from fossil fuels) in almost a straight-line fashion.

It is critical to reduce the net annual GHG emission rate to near zero by midcentury, and optimally sooner.  The IPCC released “Global warming of 1.5°C [2.7°F]. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels, V. Masson-Delmotte, and coworkers (eds.)” in 2018.

As emphasized above, the world’s policymakers had ample time to implement GHG reduction technologies in orderly fashion had they heeded climate scientists’ warnings beginning with the First AR.  These urgings have been ignored or rejected in the three decades since, with the result that future weather and climate extremes that scientists warned of at the outset have actually come to pass ferociously in recent years.  In addition, the goal of limiting warming to 2.0°C [3.6°F] above pre-industrial levels, proposed in earlier reports, has been replaced in the Special Report by a more stringent limit, 1.5°C.  Climate action has to be undertaken urgently from this time onward, to make up for the lower revised limit and the time lost in past decades. The IPCC Special Report lays out this case in great detail. 

Conclusion.  Climate scientists have been characterizing the harms and damages they expected from continued unabated burning of fossil fuels, and from other GHG sources, for more than three decades.  Throughout that period policymakers have not acted meaningfully on the scientists’ urgings to reduce use of fossil fuels, nor to reduce other GHG sources.  And now, in recent years those harms and damages are coming to pass around the globe with increasing frequency and severity.

This post presents the urgent, critical case that ambitious, aggressive, effective actions need to be taken starting now to reduce annual GHG emission rates toward zero by midcentury or preferably earlier.  Policymakers can no longer ignore the inexorable action of the physical laws governing global warming.  Industries providing fossil fuels and those using that energy seek to preserve their business models indefinitely.  This is now clearly untenable.  They must change the way they do business or get out of the way.  We all must act internationally, at the national level, at the state and provincial level, and locally; global warming originates across our planet and must be addressed by all nations and citizens of the world in concert. As many have said, “There is no Planet B!”

© 2021 Henry E. Auer

“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