Is Climate Change Real?
by David Geelan | 1 December 2019 |
I thought I’d already heard it all: that global climate change was a leftist or United Nations (UN) conspiracy to hobble the economic development of developed countries, or to install a world government, or socialism or… something. The most recent thing I’ve seen, though, in videos by people such as Elder Robert Bohr that are ardently shared on Facebook, ties some of these conspiracy theories in with Seventh-day Adventist eschatology.
The claim—based on some calls by Pope Francis for world leaders, both secular and religious, to come together to address the climate crisis—is that global climate change is a conspiracy to bring in an international Sunday law. Among a number of other things he said, the pope did mention that a day of rest, rather than working seven days, was one measure to reduce the total amount of greenhouse gas emissions. Or rather, the claim is that he said so: I will be grateful if someone can point me to a quote of his words from a credible source, because I’ve been unable to find one.
Now, while having some differences about which day to rest, Adventists might actually have some common ground on this. The Sabbath serves many purposes, including worship, time with family and church family, and rest from work. The notion of not having to work every day of our lives is an attractive one. (And there’s a whole other argument about how automation could mean less work and more leisure but capitalism keeps us working harder and longer, but that’s for another day, and maybe a different page!) The claim, though, is that the pope is using his calls for action on the climate crisis as an entry wedge for a push toward an enforced Sunday day of rest globally.
I think the evidence on that is thin at best, but am willing to see more… though I don’t have time to watch the 90-minute YouTube videos that seem to be the main vector for this particular meme. TED-talk length videos are better; text is better still.
One of the challenges in talking about climate change is that three different things are often conflated, and people will use an argument that pertains to one of those things to talk about the others. These three things are (1) whether climate change is happening, (2) what causes climate change and (3) what, if anything, we should do about climate change. Arguing that climate scientists are distorting the data in order to advance a UN conspiracy is using an argument about (3), what we should do (or what people think we should do) with a claim about (1), whether it’s happening. Let’s try to tease these out a little.
If you are 34 years old or younger, you have never in your life experienced a month that is, globally, below average temperature. July 2019 was the hottest month on record. 1998 used to be the high point used for comparisons, as an unusually hot year, but 16 of the past 21 years have been hotter than 1998. Not even those who used to deny that climate change was happening are really able to maintain that any more: the data are clear that it is happening.
Being hotter globally can mean that some areas are even hotter and some areas colder. More extreme weather increases the variability of weather—more droughts but also more floods, more fires but also more extreme cold snaps. Larger and more powerful and damaging hurricanes, cyclones, typhoons and tornadoes. Additional energy in the global weather system can disrupt important currents in the atmosphere and in the oceans.
A hotter globe means higher sea levels, too. You’ll see YouTube videos “disproving” this with ice cubes in a glass of water, or you might even have done that experiment yourself. But that’s the wrong experiment, because the way buoyancy works means melting ice that is already floating does not change the water level. Some of the sea level rise, however, will be caused by thermal expansion of the ocean water itself: things expand when they’re warmer, so warmer oceans are larger and deeper oceans. The other part is from ice that is on land, not floating in water, melting and flowing into the water. If you want to model that experiment, put the ice cubes on a tray out of the water in such a way that the melt water flows into the glass, and you’ll clearly see the water level rise. And, indeed, sea levels around the Earth are measurably rising. Only by millimeters and centimeters per year, but over time those will accumulate to make meters.
So if we’re clear that it’s happening, do we understand why? A common claim is that it is due to changes to the energy Earth receives from the sun, but in fact we are currently at a solar minimum. Studies by solar scientists have shown that changes to the sun could account for a maximum of 40% of the observed warming, but likely much less than that: indeed, the observed warming would be larger if we were not in a solar minimum.
Another is that temperature measurement stations are in cities and are part of “urban heat islands” that retain heat, and there is not real warming. Meteorologists and climate scientists have adjusted for this effect, but also many measuring stations are at sea, in wilderness, on satellites and so on. Measurement errors do not explain the observed warming. There are independent records from surface stations, weather balloons and satellites that all agree about the warming trend.
A third is that it’s all computer modeling, and the modeling is not accurate. In one sense there is an underlying truth: one of the things we do is run climate models. They’re complex and sophisticated, and they use assumptions. Not just one set of assumptions, though: multiple models are run to test multiple sets of assumptions. It’s true that many of the models have not quite matched the measured warming over time, but the alarming thing is that the models have all been too conservative. The actual warming, and the changes it causes, are proceeding faster than the models suggest.
So if it’s not the sun, and it’s not measurement or modeling error, what is it? It’s greenhouse gases. Let me explain how we know.
Earth receives the great majority of its energy from the sun in the form of short-wavelength, high-energy radiation—most of it ultraviolet and visible. It’s what we see by, and what drives photosynthesis in plants, which are at the start of every food chain. If energy only came in, Earth would very rapidly heat up and become uninhabitable. But energy is also radiated off into space, in the form of short-wavelength, low-energy infrared radiation. We need a net zero energy balance—energy out = energy in—if Earth is not to heat or cool.
Venus is closer to the sun than Earth, but it is much hotter than that difference would explain, because it has a very thick atmosphere and much more greenhouse effect. Mars is further away but colder than that would explain, because it has a very thin atmosphere and little greenhouse effect.
Earth’s atmosphere is about 80% nitrogen, which is close to being an inert gas, and about 20% oxygen, which we breathe but which also allows fires to happen. Then there are trace gases—water vapor, argon, a little helium, some industrial gases like chlorofluorocarbons, and some methane and carbon dioxide. Those last three, plus water vapor, can absorb and “scatter” (emit in a different direction) infrared radiation on its way out to space. Increasing the concentrations of these gases in the atmosphere—by burning fossil fuels, clearing forests and raising ruminants like sheep and cattle—traps more heat in the atmosphere, leading to warming.
So we know that it’s happening, and we know why it’s happening. Human activities are (a) a large part of the cause and (b) the only part of the cause over which we have any control. (If it were the sun, for example, we would have no way of changing anything about that.)
The discussion, then, is about what we can do about that. How can we change what we do as human beings to mitigate the worst effects? It’s too late to avoid all consequences, because warming has already begun and been increasing for a few decades, and because it will take decades more to bring the atmosphere back into balance. But we can act in ways that will avoid even worse consequences.
An important point to make, I think, is that it is the poorest and most vulnerable people of the world who will be harmed most. It will be Kiribati in the Pacific and the Maldives in the Indian Ocean that will be submerged, or at least washed over by storm waves and have their agricultural soil salted, by climate change, not Los Angeles or Sydney. It will be Bangladesh that will bear the brunt of more extreme typhoons and flooding around the Bay of Bengal. It will be the billions in China and India who lose reliable year-round water supplies as the Himalayan glaciers melt and vanish. It is not for ourselves that those of us in developed countries need to act, but for the vulnerable.
Interestingly, Seventh-day Adventism, with its advocacy of vegetarianism, addresses one of the issues. The digestion process that allows sheep and cattle to eat grass, with its difficult-to-access nutrients, also releases methane. Further, vast areas of the South American rainforest have been clear-felled for beef cattle grazing, as have forests around the world. Moving toward a plant-based diet is one important environmental action. (Those not ready to go that far in Australia can eat kangaroo—it doesn’t require land clearing and uses a different digestion process that doesn’t emit methane.) There are other issues with other forms of meat, but it is red meat that is most impactful.
Moving to low-emissions and electric vehicles, walking or cycling more, avoiding excessive flights and in other ways reducing carbon dioxide emissions are also important individual actions that we can each take.
But individual actions won’t get the job done. Large industries and corporations are much larger emitters than individuals. It will take governments to get on board to promote positive change—or at least to get out of the way and stop actively subsidizing fossil fuels and sabotaging efforts to build renewable energy infrastructure—to make changes on the required scale. There is a need for us to vote and protest and contact our politicians and answer polls.
Measures like carbon taxes have been promoted as incentives to people to change their behavior, but have widely been discarded. I would argue that at this point they are not necessary, and that investment in renewables is a better policy setting (renewable energy is already cheaper than fossil fuels at scale), but people of good will can disagree about which policies are most effective for addressing climate change. They can’t, in all honesty, argue about whether climate change is happening or if human activity is a contributing cause.
In a Seventh-day Adventist context, the final issue to consider is the idea that the Second Coming is imminent, and it is not really worth working to save human beings and other living things (the planet itself will be fine, with or without us) from climate change. “Our efforts should go into evangelism, rather than climate activism,” that argument goes. I’d argue that there’s enough time and energy for both (and probably other places we invest our time and energy that are expendable), but there’s also another compelling reason to be active in seeking to mitigate climate change.
Revelation 11:17-18 (KJV) reports the words of the 24 elders at the Second Coming:
“We give thee thanks, O Lord God Almighty, which art, and wast, and art to come; because thou hast taken to thee thy great power, and hast reigned. 18 And the nations were angry, and thy wrath is come, and the time of the dead, that they should be judged, and that thou shouldest give reward unto thy servants the prophets, and to the saints, and them that fear thy name, small and great; and shouldest destroy them which destroy the earth.”
The parable of the sheep and the goats in Matthew 25 says “Inasmuch as you have done it to the least of these my brethren, you have done it unto Me.”
Not for ourselves, then, but for the vulnerable people who will bear the brunt of the harm, we have a mission to act and work and advocate for measures to address the human causes of global climate change.
David Geelan is Sue’s husband and Cassie and Alexandra’s dad. He started out at Avondale College and has ended up (so far) as an Associate Professor of Science Education at Griffith University on the Gold Coast, Australia.