Global warming, greenhouse effect, and humans
Some things to consider:
- 25% of world’s energy comes from coal, 41% from petroleum; 90% of global commercial energy comes from fossil fuels
- There has been a 40% reduction in average thickness of arctic sea ice over last 40 years (not to mention recent years)–forget the exact numbers, this means the ice sheets on the poles are melting at alarming rates. And because polar region temperatures are increasing at the fastest rates, the process is accelerating–less snow means less reflection and re-radiation of heat, and more melting of ice because water retains heat, rather than reflecting it. And that’s without considering the CO2 trapped in the melting ice, released into the atmosphere. Or the methane (CH4) stored in melting permafrost.
- In the 1990s, world CO2 emissions increased 7.5%. The Keeling Curve shows a steady, relentless increase since the 1950s (pre-industrial levels were around 280 ppm vs over 400 today, meaning the Earth has had over a 40% increase in two centuries).
- This source has a wealth of information on fossil fuel production and consumption–note in particular the ‘per capita’ figures, which control for population (in other words, China has more people, Americans consume more energy per person).
- Carbon Dioxide emissions of largest consumer (does not include other greenhouse gases):
- The 20th century’s 10 warmest years occurred during the last 15 years of the 20th century–this is unprecedented for at least as long as we have temperature records–around 1,000 years or so (based on various data–samples from ice cores, cores from ancient trees (we count the number and size of the rings), cores from coral reefs, sediment at the bottom of lakes in the Arctice region (we can measure the amount of annual silt and estimate how long the melting season was), etc. But the temperature increases vary (hit ‘play’ to see the change in two decades) across the earth’s surface:
- Sea level has risen 4-8 inches globally in last century (by conservative estimates). Major melting of the Greenland Ice Sheet could mean rises in sea level of up to 10 meters (30+ feet …). More warming in the Northern latitudes creates positive ‘feedback loops’ (less reflecting ice means more heat-holding water means more melting ice …).
- The average global surface temperature has risen 1 degree Fahrenheit in the last century. Estimates are that it could increase from 1.5 to 4.5 degrees (Fahrenheit) over the next 50 years.
Some more things we know:
- In 1997, the U.S. emitted 1/5 of greenhouse gases contributed to the atmosphere by human activity. The three major greenhouse gases are CO2, methane and nitrous oxide. Water vapor is also a greenhouse gas, but water cycles through the atmosphere and planet’s surface, so it behaves differently than the other three (CO2 can persist for 100 years in the atmosphere, methane over 20 years) .
- World CO2 emissions are increasing (Largest increase: Thailand, South Korea, Taiwan–these are development success stories … models of how countries are supposed to grow their economies. What does this suggest?). Keep in mind that China has almost four times the population of the US.
- Windpower is the fastest growing energy source (30% increase in 2000), but still accounts for less than 1% of electricity. Other sources of renewable energy include geothermal, solar, water/hydropower (this has the potential to be renewable), and wood–the most common source of energy for most of the undeveloped, low income societies.
- U.S. auto fuel efficiency hasn’t improved since the 1980s (mainly because of the growth in SUV, Sport Utility Vehicle, sales)
- Greenland’s ice sheet alone, if it melted completely in the summer, could increase sea levels well over 20 feet, and displace 25% of the US population.
Scientists’ best estimates of impacts include:
- rising sea levels, which could wipe out billions of dollars worth of coastal development, critical coastal ecosystems, and force the relocation of millions of people inland. It’s not the extra inches, it’s more extreme weather and storm surges; and changes in thermohaline circulation
- a decline in soil moisture (as surface temperature increases, there is greater evaporation), which could radically alter the conditions under which we grow our food–though we produce enough food to feed the world currently, its distribution is skewed and over a billion people go to bed hungry. This number could increase dramatically if food production systems become unreliable.
- more extreme weather events, unpredictable climate change.
- increased drought–there may be just as much rainfall, but its distribution will change, more may come in the form of violent storms, and the predictability of agriculture could be affected. Some areas and ecosystems may benefit, but the overall impacts for human habitation are troubling. On top of that, feeding 7 billion people depends heavily on fossil fuels (for fertilizer, mechanized agriculture, various other chemicals used in conjunction with high-yield varieties of grain, etc.), which is how we got into this pickle. As if matters needed to be made worse . . . the most warming is happening in the latitudes nearer the North Pole, where most of the land masses and people–and much of the ice–happen to be:
- rise in sea levels (how would this affect human settlements?) Maldives, Kiribati, Marshall Islands (hundreds of Marshallese live in Union County)
- Antarctic Ice bridge
- Been to Greenland lately?
- Arctic ice melt (and everything you ever wanted to know about Antarctic sea ice)
- severe weather (what’s happening where?)
- coral bleaching (caused by warmer oceans)
- Acidification of oceans, possible changes in ocean currents
- Thawing permafrost (considerable land mass involved) releases methane
- Loss of soil moisture
- Altered climates (what will this to do plant and animal habitats, life?)
- Spread of diseases (Some of these will be invasive ‘pests,’ like deer ticks, or poison ivy.)
Things may look pretty grim. But are the changes in climates, the threats of sea level rise and greater climate unpredictability the results of natural processes, or humans’ activity? What societies might do could hinge on what they think are the causes of the climate changes. Those who think it’s the former may be the real pessimists–there’s nothing we can do, so we might as well double down on fossil fuels, right (not)?
Natural processes, phenomena to consider
We happen to be in an interglacial period–between ice ages. The earth’s orbit is complex, and slight variations in its tilt can cause temperatures in the Northern hemisphere to decrease.The patterns are complex–there are three ‘cycles’ according to Milutin Milankovitch, a Serbian scientist who figured these out as a prisoner of war during WWI.
The result of cooler temperatures, in terms of a global water cycle, is that more water freezes–a LOT more water. We’re talking thousands of feet of ice under Canadian and Northern U.S. cities. If you’ve ever been on top of Eagle Cap peak, looking down the East Fork of the Lostine River drainage, you know what rivers of ice combined with gravity can do to the landscape:
More water on the continents means less water reaches the oceans, and ocean levels drop. The current glacial period in the Northern Hemisphere began about 110,000 years ago, but for the last 12,000 years or so (coincidentally about when human civilizations began to spread and flourish), the planet has been in a glacial recession. When glaciers recede, more snow and ice melts, especially near the poles, and sea levels rise.
Solar radiation, greenhouse effect
The sun’s rays, as they reach the earth’s atmosphere, have short wavelengths, and most can penetrate. Some heat gets absorbed in the atmosphere, most rays reach the earth’s surface–oceans and vegetation hold a lot of heat (deserts are often cold at night because they have so little heat-holding capacity). But what isn’t absorbed by the earth’s crust re-radiates–bounces off. The wavelengths are longer, though, and generally can’t penetrate to leave the atmosphere. They’re absorbed by greenhouse gases, such as carbon dioxide, methane, and nitrous oxide. This is the way a greenhouse works–heat penetrates, but can’t get back out of the greenhouse–the glass retains most of the heat–enough to keep plants alive when it’s much colder outside. Without the greenhouse effect that holds heat in the atmosphere, the surface temperature of the earth would be zero degrees Fahrenheit–all water would be frozen, and the sport of ice hockey would probably outdraw baseball.
Energy and the first two laws of thermodynamics
The first and second laws of thermodynamics are critical to understanding the logic underlying the relationship between industrialism and warming. The first law states that energy can be neither created nor destroyed. That means it isn’t really consumed–just transformed into some other form. We can’t pull energy out of an empty hat, and we can’t make it go away once we’ve used it. Energy from the sun is hardly ‘free’ (just ask Icarus’ dad). Like matter, we merely transform it. Well, plants do, through photosynthesis. Most of the energy available on the earth comes from the sun. Even prime rib (think about it). And oil, coal, natural gas? Fossilized plants and animals, brought to you by The Sun 😉
The second law helps explain what happens to the energy. Transformation as suggested is usually from a ‘higher’ to ‘lower’ quality of energy. For instance, grass converts sunlight, cow eats grass, wolf eats cow (just for argument’s sake here!)–each time energy is concentrated at a ‘higher’ level in the food chain. Humans can concentrate energy–the EOU campus is an example. We’ve got buildings, landscaping, classrooms, steam pipes underground, lots of internet cable, incredibly sophisticated human bodies locomoting, etc. But if we don’t maintain those parts of the landscape, that bucolic collegial scene will begin to bleunchcccssmmmmm…. When we create order in one place (for instance, building a house–it’s a pretty ordered structure), we create slightly more disorder somewhere else–in forests where we cut trees for the house’s lumber, mountains where we mined rock for concrete, etc. Imagine if humans evacuated a city for a year–think how quickly nature would reclaim it–weeds growing up through cracks in the street, rust, no electricity to power buildings, systems to provide drinking water, treat sewage, etc., in decay. It takes energy and resources to build that city, and continual inputs of energy and resources to maintain it. That process of relentless energy decline towards disorder is called entropy. Removing the resource inputs gives us a sense of just how much is necessary to create and maintain that level of order. But for that order to exist requires that we pull the resources from elsewhere, creating some level of disorganization in someone’s backyard. So unlimited amounts of cheap energy don’t really solve all our problems–they could create lots of heat, though. And you can pull all that oil out of the ground, but you can’t make it disappear (you can burn it and put it into the atmosphere, though).
CO2, nature and humans
Carbon sources, sinks
One of the most important greenhouse gases we talk about is CO2, carbon dioxide. There are natural sources of CO2, that means places where it is produced–animals exhale CO2, when plants respire they release CO2. There are many human sources of CO2–cars, trucks, factories, power plants, etc. There are a couple of important natural sinks of CO2–oceans and plants. Tropical forests are especially important sinks–that is, they can absorb and store lots of CO2. The most important are the equatorial belts of tropical forests–they’re active year-round (forests in upper latitudes go dormant seasonally). Of course, when they die or are burned, that carbon is released, so their function as carbon sinks is easily compromised by human activity, forest clearing, etc.
Oceans are the other main sink, mostly through phytoplankton that fix the carbon. The plankton then is eaten or dies, and may transport that carbon elsewhere in the ocean (which scientists have shown actually changes the chemistry of sea water to the detriment of marine fauna).
A third more recently-recognized sink for carbon is soil. Human settlement patters (often in the richest farming regions) and annual cropping have taken billions of tons of carbon out of the soil, which stores ‘excess’ carbon from photosynthesis for other soil microorganisms. There is a difference between ‘soil’ and ‘dirt.’ The former is rich in biodiversity, the latter the result of mining topsoil and replacing lost nutrients and microbiota with chemicals–fertilizers and pesticides.
One of the key questions is whether we’ve overburdened these sinks, leading to the release of more CO2 into the atmosphere, and more heat (think deforestation, but also acidification of oceans). If you think about fossil fuels as representing ancient forests millions of years old, and incredibly concentrated to boot, then we’re releasing much more into the atmosphere than the earth’s system may be capable of absorbing, or sequestering. All that oil from 150 million years ago burned up in two centuries. And societies are clearing tropical forests at alarming rates. We know how to return carbon to the soil–increase land cover, both across space and over time (i.e., annual cropping exposes bare soil to the elements for the majority of the year).
The other two main greenhouse gases are methane and nitrous oxide. A key natural sink for methane has been permafrost, frozen soil in the arctic region. But in a warming climate, as the permafrost melts, it becomes a source of methane production, potentially billions of tons. Other ‘anthropogenic’ (human-caused) sources of even more harmful methane than the biological sources like permafrost are landfills and the waste from confined animal feed operations (CAFOs). Waste lagoons produce copious amounts of methane. Nitrous oxide is produced by industrial agricultural activity, much through fertilizer production and use.
Where are the main sources for CO2? (see the images)
The U.S. is the biggest producer of CO2, pumping billions of tons into the atmosphere annually through various forms. Which might explain why most White House Administrations are opposed to reducing CO2 emissions–it would hurt the economy (in the short run). From the rest of the world’s point of view, though, if global warming is partly caused by humans, then the U.S. is the biggest culprit per capita.
Is it humans or nature?
That’s what you might call a false dichotomy. These are natural processes, but industrial societies provide major accelerants, or forcings. Consider a few things: There is a great deal more CO2 and other greenhouse gases being emitted into the air since the start of the Industrial Revolution. Those fossil fuels were not ‘free’ (remember the first law of thermodynamics). They required energy from the sun, time, heat, compression–in other words, huge amounts of energy–to become usable for humans. The natural processes of millions of years yielded petroleum. Half of the known reserves have been used up in less than 200 years. Where did it all go?? So, using fossil fuels, if you pay attention to the first and second laws of thermodynamics, means they’ll go somewhere, in some form less usable to humans. What we get are chemical compounds with amazing heat-holding capacity, stuck in our atmosphere for a century or more. Meaning, also, that what is produced today will have effects for generations to come (we hope …).
Since discovering concentrated forms of energy–the fossil fuels–humans have burned them at an increasing rate of consumption for over 200 years. Evidence suggests that average global temperatures have increased in the last hundred years, and that the amount of CO2 in the atmosphere has risen quite dramatically over the same period. Logic and observation suggest that humans are having an impact on the greenhouse effect–essentially putting more heat into the atmosphere. Oceans also have great heat holding capacity–they take up 3/4 of the earth’s surface, and it doesn’t take a large increase in temperature to create some major changes. Ice reflects sunlight, water absorbs the heat (and melts more ice).
NASA has a site separating natural and human impacts on global warming (go down the page a bit to the ‘anthropogenic’ sources). Other so-called ‘skeptics’ take a different approach (like the Cato Institute, ridiculing those calling for CO2 reductions by referring to carbon dioxide as a ‘satanic gas‘).
There are scientists who contend that solar variation and long-term cycles may be playing out, but are masked by human activity. But the overwhelming evidence and research at this point suggests the causes are less exotic, and have more to do with human industrial activity.
Is it a social problem??
I’ll leave you to use the ways we’ve learned to analyze social problems. Three things are clear: there is a greenhouse effect; the earth’s average temperature has increased in the last 100 years, and; there will be impacts for human societies. There are clearly some very different views, or social constructions, going on. One says humans may be contributing to global warming, but the science is inconclusive (science is never totally conclusive–it can’t prove things, only test ideas and disprove them). For instance, I’ve lived in La Grande for a twelve years, and never seen a flood. I could conclude, based on that evidence, that La Grande never floods. I could say I’ve never seen massive demonstrations in the streets against the war in Afghanistan. But La Grande could flood, and I might see a demonstration at some time in the future).
Powerful groups in society that benefit from the status quo–a fossil fuel-based economy–work hard and use sophisticated PR techniques to persuade the public that:
- this isn’t a problem;
- even if it is, it’s causes are natural;
- there is no consensus among the scientific community that warming is occurring and caused by humans;
- these research ‘findings’ are brought to you by the oil and gas industry (hey, how’d that get in here??)
Of course, we all benefit from these circumstances in the short-term. At least relative to other societies with much lower material living standards (however, European societies have comparable living standards with smaller carbon footprints). Just how dependent are we on fossil fuels? Do you drive (cars and their production)? On roads (where does tar come from)? Use electricity? Any plastics in the home? Synthetic fibers? Do you eat food (fertilizers and pesticides require massive amounts of fossil fuel, combines, trucks consume large amounts of fuel)? Buy things (they come from China quite often–how do you think they get to ports, and to the store)? Heat your home/apartment? Ever travel by air? Without fossil fuels, our economy comes to a grinding halt. Reducing our consumption of fossil fuels could hurt the economy, just like increased fuel prices would increase the price of practically everything we buy.
So, why does government policy support increased use, exploration and development of fossil fuel supplies? National and economic security, we’re often told, and reduced dependence on ‘foreign oil.’ Then there’s the war, occurring in the country with the second largest known petroleum reserves in the world. But there is more to it than that. There are large campaign contributions made in return for favors, and as we’ve discussed in class, winners in political campaigns are in over 95% of cases the candidates who spent the most money. And frankly it would be hard for any politician to tell people to consume less, pay more for gas, ride bicycles more, reduce, reuse and recycle, pay much more for using the landfill, etc.
As for the science being inconclusive, scientists say that the difficulty with this is that the effects of global warming may take several decades to manifest themselves. CO2 remains in the atmosphere for up to 100 years. Methane for much less time, but it absorbs much more heat. Nitrous oxide for less time, but it has much much higher heat-holding capacity than even methane. But CO2 is the big one. If societies don’t address the problems now, it may be too late by the time sea levels have begun to rise, or extreme weather increase. The effects of what we do today may not show up for several decades, in other words. There is a lag time. Those opposing doing anything about global warming often call the scientific community ‘alarmist‘ (see Chris Horner’s background).
Are these natural processes? Climate changes, the earth is a dynamic place, humans contribute only about 5% of the total amount of greenhouse gases to the atmosphere, and therefore we shouldn’t hurt economies that depend on fossil fuels, because they’re not responsible for the current problems. Addressing this one is tricky–do we just assume that Mother Nature always bats last, and make no effort to address the melting of ice caps or changing climates? They will have drastic effects on human populations. At the least, we should be planning for a possible increase in sea level, or climate changes that make it more difficult for agriculture in some places. The CATO Institute is a conservative think tank that has researchers working on global warming (but to be quite honest, their research doesn’t appear in rigorously peer-reviewed scientific journals, and is financed by heavy corporate backing). The Competitive Enterprise Institute calls CO2 ‘earth’s organic fertilizer.’ But we know what greenhouse gases do once in the atmosphere, we know humans are producing billions of tons of them annually, mostly through industrial activity, and we know that humans get no exemptions from the laws of thermodynamics.
A third framing is that global warming may in fact be occurring, and that humans have played an important role in changing the balance of greenhouse gases in the atmosphere. True, the science can’t ‘prove’ it. But the logic is compelling, as is the evidence of increased global average temperatures. Over 95% of the scientific community agrees that global warming is occurring, and that humans are playing a central role in this process. Humans have emitted trillions of tons of CO2 into the atmosphere since the beginning of the Industrial Revolution, and have deforested large areas of the earth’s surface as well, especially in the tropics in the last 3 or 4 decades–meaning more CO2 in the atmosphere, and less trees to fix and absorb all that carbon. Evidence from average global temperature records also suggest substantial increases since the beginning of the 18th century, when industrializing societies began using coal-fired steam engines.
As for the business community, it’s hard to support a movement that may increase the costs of goods, decreasing consumption, and potentially profit margins. So in terms of framing among a group with lots of resources to influence the public, we wouldn’t expect much (and perhaps one might expect some counter propaganda to dismiss or minimize those trying to highlight the urgency of the problem). However, this is changing, and think tanks like the Blue Green Alliance work on policies that will stike a balance between environment and economy.
The politics are deceptive–economy or ecology? That’s a false question. There are economic costs whether humans act or not. Where do societies strike a balance? Should we curb greenhouse gas emissions, even though those countries most dependent on fossil fuels will pay the heaviest price? What if the price of gasoline doubled, tripled, quadrupled? Would people change their habits? Who could afford to buy scarce petroleum? How many people can afford to drive less? Our cities and surburbs are set up for automobiles. Will it just mean less money for some, who have no choice but to drive to work? Will people carpool more? Will cities develop better mass transit systems? The price of gasoline in Europe is 3-4 times what it is here in the States. Why is it so cheap here? Who benefits from inexpensive gasoline, whose price doesn’t reflect some of the problems it causes (pollution, more health problems for people in cities, urban congestion, etc.)? Or should we dismiss the science and keep increasing our use of petroleum? Humans have been on the planet over 150,000 years, according to the fossil record. The earth is close to 6 billion years old. There are no guarantees for species survival . . . Some of the social problems we discuss in class may pale in comparison to this one in the long run. If the climate changes, and food production becomes an uncertain proposition for the close to 7 billion humans, then some of the other issues we discuss in class may seem like window dressing.
. . . Okay, that’s pretty gloomy. My point is, this is one of those problems where the possible consequences of ignoring it could be catastrophic. Compare this to the economic consequences of taking action. Some people, especially technological optimists, say that humans will figure all of this out before it is too late–humans are ingenious, and will always come up with some way, sometimes at the last minute, to save the day. Technology is progress–how could it be leading to the sorts of catastrophic events being predicted? Somehow, science and logic and observation isn’t good enough for them, but technological optimism, which is grounded in pretty flimsy whims about human nature, works just fine! So . . . as with the other things we’ve discussed, be able to go through this one and discuss it. If it isn’t a social problem according to you, back up what you say with some logic or evidence. That’s the key–show that you understand something about the problem, and that you can think about it as a social problem with all of the things we’ve discussed related to social problems.
And there is hope, if the balance of power in this debate shifts away from corporate industry and pandering politicians. We actually have a pretty good idea–getting better as we understand the mechanisms of warming better–about what needs to be done. That doesn’t mean there wouldn’t be pain in doing it, in fact it means that the longer humanity waits to respond, the more pain the changes are likely to bring.