Sense and Nonsense in the Climate Change ‘Debate’

In a recent email conversation with friends and acquaintances, two conservative correspondents sought to challenge the scientific consensus on climate change and its impacts by citing facts they believed undermined the accuracy of that consensus.

One tried to debunk the issue with a recent Wall Street Journal reprint of a 1989 news article in which a U.N. environmental official said that rising sea levels could eliminate whole nations if the global warming trend was not reversed by the year 2000.  Another raised a familiar ‘challenge’ by asking how we can explain major weather changes hundreds of years ago before industrialization and the invention of the internal combustion engine.

More substantially they also pointed to the NASA finding in 2015 that the ice sheet in Antarctica is growing rather than shrinking, contradicting other studies that found a loss of ice mass in that region as they have also found in Arctic ice.

Unfortunately, with so much at stake, a pro-market/anti-environmentalism ideology drives such grasping at straws in the effort to debunk the nature and urgency of climate change.  Just as unfortunately the climate change skepticism or denial expressed above betrays a misunderstanding of science and of how it develops.

Professional science is a rational and developmental project, continuously seeking to test its own assumptions and findings with ever more sophisticated measurement techniques as knowledge accrues.  It is especially energized by its own failures and errors.  It is distinctly NOT an ideological process.  Properly understood, science should help us to avoid endless political arguments about the nature and causes of major social problems.  These include not only problems in the natural world, but also those in the social world (poverty, discrimination, health and illness, etc.)

The first thing I see in the 1989 piece is that the projections reported have not been importantly contradicted by later events.  It does NOT claim that the predicted results will occur by 2000.  Instead, it refers to the idea that by 2000 climate change will have reached an irreversible ‘tipping point’ beyond which societies will be unable to reverse disastrous effects.  The year 2000 as the timing of that tipping point was premature, to be sure, and scientists remain unsure about when (even whether) such a tipping point might be reached.  But the view that humans are causing climate change through high and growing discharges of CO² and that it is related to sea level rises, melting polar ice caps and increasingly disruptive weather events and cycles, is increasingly supported by scientific investigations.

This scientific confidence—and consensus—simply comprises the natural process in science of progressively correcting its errors, refining its interpretations, and sharpening its predictions with ever improved data.  NASA presently reports that 97 percent of climate scientists worldwide agree that human behavior since the industrial revolution has increasingly caused climate change.

To deny these climate processes is not only for us to climb out on a limb, but to ask our grandchildren to jump off that limb from a very high elevation.  In addition to the threats to us directly from nature (and, according to a major new United Nations assessment, to nature), the Pentagon has for years been planning and war-gaming for foreseeable threats to our national security due to the impacts of climate change (major flooding, food and water scarcity, international migrations to escape same, etc.).  The American president’s climate change denialism has been called out by former US military leadership for undermining the country’s security.

The American Association for the Advancement of Science reports that the planet’s climate is on a trajectory to grow warmer beyond the range experienced over the last millions of years, that our present warming path may bring vast disruptions to societies and ecosystems, and that failure to act to reduce climate change will increase the costs and impacts of climate change, escalate risks and close off options for addressing future risks.

It is also important to realize that faux comparisons to changes in climate in eons past are irrelevant to our present circumstances.  We know (1) that human behavior, particularly emissions from burning fossil fuels, is a major cause of climate change now; (2) that this change has already disrupted human affairs; (3) that measures are available technically and economically that can ameliorate the problem, and (4) that the harmful social and economic consequences of climate change are without precedent given the growth of human populations and their patterns of settlement.

There is little doubt that the social costs of climate change have already begun to accrue: floods in low lying areas of human habitation, droughts afflicting food and water supplies, fires.  (We could, with a bit of an extension, include Oklahoma’s many earthquakes, due as they are to the processes of extracting oil and gas in the state.)  And we know that the climate change-denying American president is familiar with these causes and consequences.  Check out the wall he is actually building—around his golf course in Scotland to protect it from rising sea levels, which he acknowledges are due to climate change.

Finally, that there has been ice growth in some places in Antarctica is no refutation at all of climate change findings and science.  Instead, it comprises a very common result in science: it is an apparent anomaly that requires specific explanation because it defies existing general models of climate change.

The earth’s climate is the consequence of very complex and dynamic atmospheric and geologic processes.  As such it is difficult to model precisely.  Climate scientists agree that existing models of climate change cannot explain this growth in the South Pole’s ice mass.  Instead it requires specific explanation using observational data.

And that explanation is in the works: it has to do with the specific geological conditions (configuration of the ocean bottom) and ocean and air currents in that region that insulate at least some of the polar ice from the effects of the warming climate.  Notably, the net loss of polar ice, taking into account the much larger loss of ice in the Arctic than has grown in the Antarctic, has been massive: 13,500 square miles per year of sea ice is being lost.  And more recent research on two Antarctic ice shelves in Western Antarctica finds that they are melting from below due to warming in deep currents, rather than from water temperatures above.

So we might say that science is getting to the bottom of the apparent anomaly.

Or we could avoid the pun altogether and simply follow the science where it takes us, as the US Military and Citizen Trump already are.