The Climate Change Debate

Climate change has become one of those issues so thoroughly bound up in ideology that there is little reasonable public discussion about it from either side.  There are in fact three separate issues involved:

1.      Is the worldwide climate changing?

2.      If so, to what extent is the change man-made?

3.      If it is man-made, what is the most reasonable response?

1.  Is the worldwide climate changing?

The short answer is almost certainly yes.  Worldwide 16 of the 17 hottest years on record have occurred since 2000, and this year (2016) looks on track to be the hottest year yet. Worldwide the global temperature has increased about 1.4 degrees Fahrenheit since adequate records began to be kept around 1880.  But the change is not uniform over the globe – some places have even gotten colder, and local temperature variations can be higher or lower. However the changes are becoming quite visible in the changes in growing seasons, the changes in vegetation, the thawing of permafrost, and the shrinking of polar ice packs and mountain glaciers.  Climate change deniers like to cherry pick the data to argue their case, like noting that the hottest year in the US was 1934 (but that was the US, not global).  But the evidence is pretty conclusive that the globe is warming.

2. To what extent is the change man-made?

The short answer is that almost certainly some of the change is the result of human activity. We know enough about the chemistry and physics of greenhouse gases to know how they operate to trap heat, and we have good enough instruments to be able to measure pretty accurately the concentration of these gases in the atmosphere. There is no question that greenhouse gas concentrations have increased substantially since the beginning of the industrial revolution, and by techniques like analyzing air trapped in pocket of ancient glaciers we can map the increase over time pretty accurately. Before the industrial revolution, carbon dioxide (one of the greenhouse gasses) was about 280 ppm (parts per million) – now it is past 400 ppm. Unless all we know of chemistry and physics is completely wrong, (pretty unlikely) this is having a significant warming effect on global temperatures.

There is a legitimate debate about exactly how much of the warming effect is man-made and how much might come from other sources, but climate change deniers have proposed no other likely source that would account for any significant part of the observed rise. The best they can offer is the observation that random variations do occur, which is true but not very convincing.

3. What is the most reasonable response?

This is the question that ought to be getting the most public and policy debate. It is not as simple as simply replacing all fossil fuels with renewable energy. For one thing, carbon dioxide isn’t the only greenhouse gas. Carbon dioxide accounts for around 80% of the greenhouse gasses emitted by industrialized nations, but methane, while only around 10% of emitted greenhouse gases, is about 20 times more potent in trapping heat, and it comes from things like cows, rice paddies, and rotting vegetation and sewerage, and methane being released from frozen deposits on the ocean floors, not things so easily controlled.

Then there are the economic issues: about 70% of US power and electricity comes from fossil fuels, far more than can be replaced any time soon by renewable energy sources. Any significant cut in that energy source will have profound impacts on the economy, on transportation, on food production, and on industrial output. The result might well be more disastrous than climate change.  I think most people are unaware of how dependent just about everything in their daily lives is on energy. Without adequate energy we wouldn’t grow enough food to feed everyone, nor could we transport what we did grow to where it was needed, nor keep it from spoiling, nor cook it. We couldn’t run most of our offices and factories and stores.  We couldn’t heat and cool our homes, nor make many of the products we use every day.

There are things that can be done, of course. We could shift to more nuclear energy, which can be made pretty safe if we adopt some of the newer approaches (for example, subcritical accelerator-driven reactors; turn off the flow of neutrons from the linear accelerator and the nuclear reaction stops instantly). We could try to capture more of the carbon dioxide from combustion processes. We could reduce the amount of beef and milk we produce (there are an estimated 1.3-1.5 BILLION cows in the world, producing about 25% of the methane emitted into the atmosphere). We could undertake a massive reforestation project around the world, since trees absorb vast amounts of carbon dioxide.

What I am suggesting is that simply reducing carbon dioxide output may not be the only solution, nor even the best solution.  The issue is far more complex, and deserves a far wider, and more rational, debate than it is getting now. Climate deniers won’t even acknowledge the problem. Green advocates are too focused on a single “silver bullet” solution – reducing carbon dioxide emissions - and seem oblivious to the economic consequences.  The problem is more complex than that, and the solution will be too.