I recently visited my sister- and brother-in-law in Washington, DC. They both worked for government agencies for decades, and have both retired, though they're contracting back to the departments they retired from.
He's a climate-change skeptic. He has a background in physics, math and languages, and worked as a technical analyst for 40 years. He believes that increases in carbon dioxide concentrations will not cause global warming. His "proof" is that there was a large increase in global temperatures between 1970 and 1998 (which was the hottest year on record), and since then the increases in atmospheric temperatures have been "almost" flat even though CO2 levels have increased almost 10% (from about 367 ppm in 1998 to around 400 ppm today).
When he "proves" this to me he uses Google to summon up charts of CO2 levels that show that CO2 has continued to rise at "dramatic" rates, and then he summons charts of atmospheric temperature that show only a slight increase. When he eyeballs the charts he is convinced the very wobbly curve of mean global temperature is completely flat. When I eyeball it, I see a slight rise (which is upheld in the actual data).
According to him, CO2 doesn't cause global warming because the rate of change has
gone down since 1998 while CO2 levels have
gone up! This is the commonest trick of skeptics -- they repeat over and over that
the rate of change going down! Whenever someone talks about the rate of change instead of the actual change be very wary. They're probably trying to slip something past you.
The fact is,
mean global temperatures are still going up, albeit more slowly since before 1998. Hotter is still hotter, even if it's getting hotter more slowly.
Thirteen of the 14 warmest years on record have occurred since 2000. It's 2014. You do the math.
If you mention the "97% of climate scientists" who agree that global warming is anthropogenic, he lays into you with a canned story about how that number was arrived at by some cartoonist who reviewed climate papers and tossed out those that didn't state a conclusion about anthropogenic climate change. The thing is, that's not how scientists work. The point of most papers is not to prove or disprove global warming, but to provide data about some aspect of the physical world. In papers about tree rings, or CO2 levels in ice cores, or arctic sea ice coverage the personal opinion of the author about global warming is not germane: only the data matters. So you would expect the vast majority of papers reporting climate measurements to not venture an opinion about anthropogenic climate change.
Just like you wouldn't expect the nurse who takes your temperature and blood pressure at the doctor's office to offer an opinion about whether you'll die of a heart attack. It's more complicated than just one measurement.
The 97% consensus conclusion has been arrived at by at least three different papers, which are cited on a
NASA page on climate change consensus. They were published in the
Proceedings of the National Academy of Sciences,
Eos Transactions of the American Geophysical Union and
Science, not the comics page of the
New York Daily News. One of the papers actually
surveyed climate scientists [
Doran], and found that 97.2% of actively publishing climatologists said yes, "human activity is a significant contributing factor in changing mean global temperatures."
Then my brother-in-law delivers his "gotcha" question. "Do you believe that the increased concentration of CO2 will make the concentration of other gases go down?" Well, yes, but so what? I ask. The sheer quantity of CO2 in the atmosphere is going up. With more CO2, more infrared photons reflected from the earth's surface will be absorbed by CO2 and heat the atmosphere instead of radiating into space, because there are
more CO2 molecules to absorb it. The relatively lower concentration of other gases won't lessen that effect. When I say this he has no real response, apparently ignoring the physical reality of the greenhouse effect.
Even though he thinks he has given this a great deal of thought, when I ask him directly what physical mechanism will prevent that larger number of CO2 molecules from absorbing a larger number of reflected infrared photons, he has no answer.
Though the relative concentration of gases in the atmosphere is apparently the capstone of his argument against anthropogenic CO2 greenhouse warming, he seems to have simply stopped there. He apparently has not tried to determine what that effect might be. Here's some analysis:
The most basic result of fossil fuel combustion is that each molecule of CO2 produced removes one free molecule of O2 (oxygen) from the atmosphere. The reactions for
burning natural gas and isooctane (one of the components of gasoline; other components are similar) are:
CH4 + 2 O2 → CO2 + 2 H2O + heat
2 C8H18 + 25 O2 → 16 CO2 + 18 H2O + heat
That is, burning fossil fuels creates two greenhouse gases (CO2 and H2O),
warms the atmosphere directly by releasing heat from the chemical reaction, and
directly reduces the amount of free molecular oxygen in the atmosphere. Burning fossil fuels does not simply change the relative concentrations of gases because we're adding more CO2. It destroys free oxygen and creates carbon dioxide, locking the oxygen up in CO2 molecules until something else
uses energy to separate the carbon and oxygen molecules -- say, a leaf struck by sunlight using photosynthesis to convert CO2 and water into glucose and oxygen. This is why CO2 stays in the atmosphere for a long time -- it takes energy to take it out of the atmosphere and store it in the form of plant material.
Water vapor in climate models is the wild card -- it's very difficult to ascertain whether the greenhouse warming effects of the water vapor will be greater than the cooling effects of clouds and potential snowfalls. Climatologists are always careful to note this.
My brother-in-law doesn't mention the actual chemical reactions of fossil fuel combustion at all. The only thing he
will say is that there's no
proof that more CO2 will cause the temperature of the earth to rise. He says this even though he admits that CO2 and water vapor are greenhouse gases, and that the greenhouse effect is real and is in fact what makes earth habitable at all (mostly due to water vapor). Without the greenhouse effect, we know from second quarter physics that the
temperature of the earth would be less than zero degrees (255 Kelvins). Venus and Mars, which have mostly carbon dioxide atmospheres, are also warmed by CO2's greenhouse effect (the temperature on Venus -- 850 F -- is hot enough to melt lead and zinc: pennies dropped on a Venusian sidewalk would melt).
So, he insists that I accept the existence of some unstated process that will neutralize the greenhouse effect of CO2 when the relative concentrations of atmospheric gases are changed because of the introduction of
more CO2 and the
elimination of an equivalent amount of molecular oxygen. And he thinks that
I'm being unscientific because I won't accept the existence of that mysterious, unknown and unstated effect.
In any case, CO2 and water vapor are not the only things we put into the atmosphere. For decades the chlorofluorocarbons we used for refrigeration escaped unnoticed into the atmosphere. When we discovered that it was creating a hole in the ozone layer (causing increased UV exposure and ultimately more skin cancer) the governments of the world agreed to cut down on CFC production, and switch to other gases.
The thing is, CFCs are powerful greenhouse gases that do not occur naturally and last a very long time. The CFC protocol has been successful, and CFC concentrations
have declined by more than 10% since 1992. Raw concentrations of CFCs are much lower than CO2, but their
global warming potential is 10,000 times greater than CO2's. Is it mere coincidence that the fastest increase in mean global temperatures occurred while CFC concentrations increased? Has some of the slower temperature increase since 1998 been due to falling concentrations of CFCs?
Since 1998 China has overtaken the United States as the largest emitter of CO2. Most of China's emissions are from coal-fired power plants. At the same time the United States has been using much less coal, and more natural gas. Burning coal puts aerosols in the atmosphere that block sunlight and make the earth cooler. This has caused "
global dimming." Injecting aerosols such as sulfur dioxide, hydrogen sulfide or carbonyl sulfide into the stratosphere has even been suggested as a
"geoengineering" solution to global warming.
In other words, we may not be seeing temperatures rise as fast since 1998 because China is putting so much crap in the air that it's blocking sunlight and slowing the temperature increase that higher CO2 levels would cause. It's also
killing millions in China.
We also fly
a lot of airplanes, and those planes emit CO2 and water vapor, forming contrails in the stratosphere. Like clouds, contrails reflect sunlight and infrared, which has the effect of
lowering the temperature at the earth's surface during the day and increasing it at night:
The near-total shutdown of civil air traffic during the three days following the September 11, 2001 attacks afforded a unique opportunity in which to observe the climate of the United States absent from the effect of contrails. During this period, an increase in diurnal temperature variation of over 1 °C (1.8 °F) was observed in some parts of the U.S., i.e. aircraft contrails may have been raising nighttime temperatures and/or lowering daytime temperatures by much more than previously thought.
In recent years the arctic ice cap has receded drastically during the summer, leaving more deep blue sea exposed to sunlight, causing more evaporation and more water vapor in the atmosphere. More water vapor may mean more clouds, which may increase the earth's albedo (reflectivity), which may cool it.
Indeed, the old argument against global warming was that there was some "natural" mechanism that would keep temperatures stable and that water vapor, clouds and snowfalls would prevent a runaway greenhouse effect. Which is true to an extent; no one thinks that earth will turn into another Venus any time soon. But it's completely within the realm of possibility that earth will return to the state it was in during the Cretaceous period, with much higher mean global temperatures and sea levels 20 meters or more higher than now.
Which is exactly what climate scientists are concerned about: they're not saying we're entering some strange new world that has never been; they're saying that we're causing in 100 or so years something that would have taken millions of years to happen naturally. We're creating conditions that once existed on the planet that will not be conducive to raising crops adapted to our current climate. They're saying that that billions of people will be at risk of death or being displaced when rising sea levels make hurricanes more destructive to coastal areas and flood major cities like Miami and New York. All of which will cost trillions of dollars.
Furthermore, the temperature of the
atmosphere is not the only thing that matters. Ocean temperatures have continued to rise, as well as sea levels (due to both expansion and glacier melt), since 1998.
Deep ocean temperatures have risen; it may well be that atmospheric temperatures are rising more slowly and ocean temperatures are rising more quickly. Since water has greater thermal inertia, and there's so much more ocean than atmosphere, even tiny increases in ocean temperatures could hide planetary warming if all you do is stare myopically at mean global air temperatures.
The thing is, the sea doesn't have to boil to cause problems. Coral reefs are very sensitive to temperature changes, and higher CO2 levels have increased the acidity of the ocean, which is literally eating away the shells of certain sea creatures and causing
coral bleaching. Which means significant changes in ocean ecologies, potentially leading to a collapse of our fishing industries.
In his arguments my brother-in-law doesn't concern himself with these practical, real-world effects of climate change. The
only
thing he zeroes in on is atmospheric temperature increases due to
anthropogenic CO2. He cares not one whit for any of the other aspects of
climate change, instead demanding
proof that higher CO2 levels will increase atmospheric temperatures.
He complains about how CO2 levels obtained from ice cores 10,000 years old are "smeared" because of migrations of bubbles in the ice. There might be, he says, huge spikes of CO2 like the ones we're encountering now, but we just can't see them because they're averaged out. This might be true, but it's mostly irrelevant. The average is in fact what matters, and there was nothing during those periods creating the massive infusions of CO2 that we
know we are creating now. As long as we burn fossil fuels at our current rates, the CO2 levels will continue to rise and stay at those high levels for decades and centuries, even after we stop spewing CO2. There is no dispute that we are responsible for almost doubling CO2 levels since 1750; the only thing climate skeptics can dispute is whether that increase will have serious consequences.
He also completely ignores forms of climate change that have nothing to do with burning fossil fuels. We have deforested vast areas of the planet: in the Amazon hundreds of thousands of square kilometers have been burned and turned to crop production, mostly soy beans and sugar cane. Burning trees not only puts CO2 and particulates like soot into the atmosphere, it also changes the local climate. Trees keep soil temperatures cooler and reduce water loss due to evaporation. There's also evidence that trees actually induce rainfall; replacing them with crops actually reduces the amount of rain the land receives. In the American Midwest millions of acres of oak savannas and prairies have been converted into cropland since the 1800s. That changed the climate, exacerbated the drought and caused the
Dustbowl of the 1930s.
But my brother-in-law brushes off all these other things. He simply insists that there's no
proof that CO2 is increasing global temperatures, and ignores everything else.
So, I have to ask myself why my brother-in-law would become a climate skeptic. He is a very smart guy. He knows it, and he revels in making sure everyone else knows it. He says that he hates fossil fuels. He says he used to accept anthropogenic global warming but when he "looked into it," he found the arguments against it convincing.
But I'm not convinced of the genesis of this belief. He appears to be viscerally
disgusted by people who accept anthropogenic global warming "almost like a religion," without understanding any of the science behind it. I can certainly understand why someone would dislike people accepting unsubstantiated dogmas as truths.
But there's more to it than that. He has an underlying personality tic that leads him to want to intellectually trump everyone he meets. He is a contrarian not just about global warming, but about everything. This, rather than the science, seems to be the true root of his skepticism of climate change.
He has a devilish little smile when he relates stories of how he confounds the annoying drones who are responsible for quizzing him for the routine security clearance for his government job. The smile also appears when he describes how he has consistently failed his polygraphs, and his interrogators insist must be hiding
something (I'm sure he's not; he's just yanking their chains). It appears when he describes the inadequacies of the man who used to direct the musical group he's a member of. And he has that same devilish smile when he talks about climate change. Some would call that smile arrogant or supercilious. Some would call it a sneer, rather than a smile. I simply find his anecdotes entertaining. Most of the time.
When I realized that, I finally understood why he has no explanation to back his thesis of increaseing CO2 concentrations and the greenhouse effect; a large part of his skepticism is due to his quirky contrarian personality, which has only been amplified as he has entered cranky old codgerdom (a process with which I am personally familiar: my codgerdom manifests itself as a dogged refusal to let people get away with bogus arguments).
Non-scientific motivations are common among climate skeptics. For some it's economic: they think it would damage the economy (or their personal wealth) if we reduced CO2 emissions. For some it's resignation: they think it's politically impossible to do anything to stop it, so we shouldn't even try. For some it's spite: they reflexively oppose anything their enemies hold to be true, regardless of its scientific or moral validity, or even if they themselves believed it at some point in the not-so-distant past. For some it's apathy: they'll be dead, so why should they inconvenience themselves to save other people's grandkids? For some it's incomprehension: they have no idea what those guys are talking about, so they're just going to ignore it.
From the science it's obvious that the issue of climate change is extremely complex.
There are many variables, and we're doing all sorts of things that will affect climate, some increasing and
others decreasing mean global temperatures. Neither I nor my brother-in-law are
trained climate scientists, though we have comparable levels of education in
the sciences. But neither of us knows enough real climate science to
make any kind of definitive judgment about the scientific evidence. Both of us must
rely on others to provide and interpret the data. He chooses to rely on climate skeptics who have pecuniary interests in the status quo, spend millions of dollars trying to discredit climate scientists with campaigns that include hacking the email accounts of scientists, inundating West Virginia, Pennsylvania and Ohio with billboards touting "clean" coal and denigrating wind and solar power, and spreading innuendo and rumor across the Internet. I choose to rely on real climate scientists who make the actual
measurements, create physical and mathematical climate models, write complex computer simulations that are verified against
historical data, and publish in refereed scientific journals.
It's always a good idea to reexamine your data, revisit your analysis and make sure that you haven't fallen prey to group think. I do not think that's what my brother-in-law has done. He posits that the basic physical properties of carbon dioxide will change based on the relative concentrations of other gases. I think that's incorrect; CO2 is a greenhouse gas, and we're putting a hell of a lot of it into the atmosphere. Unless we're also putting stuff into the atmosphere that's lowering temperatures or doing something else that creates a cooling effect, increasing CO2 levels will increase temperatures. It's simple physics.
Ultimately, global warming is not the only reason to stop burning fossil fuels. Getting them out of the ground is dangerous and dirty (extracting them kills miners, poisons our lakes, rivers, and aquifers, and causes earthquakes). Burning them fills our air, land, lakes and rivers with disease-causing gases, particulates and toxic waste. And there's only a limited quantity of fossil fuels; once they're gone, they're
all gone. No matter how many arctic wilderness areas we drill-baby-drill, the supply of fossil fuel is finite. Ultimately we will have to turn to other energy sources.
With all the other problems that burning fossil fuels cause, the conservative thing to do is wean ourselves off them while we still have the energy and financial resources to make the transition safe and easy. If we put off the switch until all the oil and gas are gone, we're guaranteeing ourselves a very dismal future as all the countries of the world fight over the few remaining patches of oil under the north pole and the deep ocean floors.
If moving away from fossil fuels is too difficult for us now, imagine how much more difficult it will be when we have to deal with drought, floods, food shortages, disease, sea level rise, and mass migrations of people from coastal areas.
