One of the more controversial topics of our current time is climate change. One group which includes the vast majority of climate scientists believes recent climate change is occurring and is primarily caused by greenhouse gases produced by humans. Another group, smaller in number but vocal, doubts whether the climate is changing very much by human activity. We will refer to the second group as skeptics rather than “denialists”,
I find myself in a somewhat odd position much like that of the late Alexander Cockburn. I really don’t fit the mold. While I generally believe in a very progressive political agenda, I maintain a degree of skepticism about the accepted climate science, although I do not agree with Cockburn’s belief about most of our rising carbon dioxide levels in our atmosphere being part of a natural process. My skepticism is not a complete rejection of climate science but more of a rejection at the edges. In other words, I think something other than greenhouse gases is having an effect on climate change even if greenhouse gases may be the predominant driver. It may be solar influences, natural variations , galactic cosmic rays, or something else we don’t understand but I don’t accept that all of current warming is the result of green house gases. This is not a particularly radical or skeptical position. Most climate scientists leave some role for solar influences particularly over the long-term and there is still a good deal of debate about how much natural variability is behind recent warming even if the general consensus is not very much.
My argument here is that no matter what one believes about global warming and its causes, the discussion is completely missing the point. Let me provide some background before I get into my main argument.
The climate on Earth has changed significantly over time. The Earth has been significantly warmer and significantly colder in the past than it is now. These changes have been driven by solar influences, the migrations of land masses, volcanic activities, and perhaps other feedback mechanisms we don’t understand.
When we look at the last several million years, Earth’s climate has been influenced primarily by orbital and geological forces. The closing of the gap between North and South America at Panama and the rise of the Himalayan mountains have undoubtedly had a significant role in the development of our climatic state. We are living now technically in an Ice Age. We have alternating periods of ice with briefer periods of warmth. These probably have been driven by orbital variations and the Milankovitch cycles. Our current period – the Holocene – is but the latest warming period in a series of warming periods that have occurred every hundred thousand years or so for the last several million years. We actually live in a very privileged time – a time of warmth and not a time of ice. This has undoubtedly allowed us as humans to prosper in ways we hardly appreciate. Today we grow corn and soybean in areas that were covered by gigantic ice masses at the peak of the last glacial maximum twenty thousand years ago.
When we look at the last ten thousand years or so, we also see colder and warmer periods though not as extreme as difference between glacial and non-glacial times. About a thousand years ago there was the Medieval Warm Period when world temperatures were much the same as they are today and several hundred years ago there was the Little Ice Age when the world was a lot colder. These variations have been caused possibly by changes in solar output, volcanic activity, or other natural cycles not completely understood. These periods are a source of considerable debate because they show that the Earth can become warmer or colder largely through its own natural cycles with minimal human influence.
In the last hundred to two hundred years, we have been engaging in a grand experiment of injecting large amounts of carbon dioxide into the atmosphere. This carbon dioxide has the effect of trapping an additional amount of radiation that would have dissipated into space nearer the Earth’s surface. This is the greenhouse effect. Actually few skeptics doubt the science of this. Most of the debate between the accepted climate science and the skeptics is over the magnitude of the effect on temperature of this additional radiation and the extent of other factors that are also affecting climate or might even mitigate this effect.
The Intergovernmental Panel on Climate Change (IPCC) depending upon ones viewpoint represents either the scientific consensus about climate or a global left-wing conspiracy to bring about world socialist government. The IPCC has issued four reports on climate change and its impacts. The last assessment report called ARV4, issued in 2007, consists of four parts: an overview of the science of climate change, an attempt to gauge the impacts of climate change, a consideration of mitigation strategies, and a high level summary. While most of the debate between skeptics and scientists focuses on the first part dealing with the science, the bigger issues in my view are in the second and third reports. Even if we accept the scientific consensus that the Earth undergoing significant warming caused by human greenhouse emissions, this provides little value unless we understand the impacts and, if we do not fully understand the impacts, then mitigation strategies are almost beside the point.
I have no intention of engaging in the debate here about how much green house gases have warmed the Earth or the degree of the warming caused by them. For the sake of argument here, let us simply accept the current most pessimistic IPCC scenario that says the Earth will warm 2.4 – 6.4 degrees Centigrade and sea levels will rise 0.26 – 0.59 meters in the next hundred years.
First, these are fairly broad ranges and we might imagine the difference between 2.4 and 6.4 in terms of impact could be considerable. But let’s proceed anyway assuming something around the middle of the estimates.
Now what? What is the effect of this warming? What does it mean to humans? Is it good, bad, or mixed? Can we even alter this course without other detrimental effects?
Here is where the science becomes more difficult.
So how well do we understand the impacts of climate change? Let me provide some quotes from the second report. (Working Group II Report Impacts, Adaptation, and Vulnerability)
“Joint attribution involves both attribution of observed changes to regional climate change and attribution of a measurable proportion of either regional climate change or the associated observed changes in the system to anthropogenic causes, beyond natural variability. This process involves statistically linking climate change simulations from climate models with the observed responses in the natural or managed system. Confidence in joint attribution statements must be lower than the confidence in either of the individual attribution steps alone, due to the combination of two separate statistical assessments.” (Section 1.2)
Do you get that? We have to combine results from models with observed changes. The changes, by the way, are sometime subtle and affected by many other factors as well as natural variation. The models are to varying degrees imperfect. We cannot measure the impact of global warming directly in any way.
“Both climate and non-climate drivers affect systems, making analysis of the role of climate in observed changes challenging. Non-climate drivers such as urbanization and pollution can influence systems directly and indirectly through their effects on climate variables such as albedo and soil-moisture regimes. Social-economic processes, including land-use change (e.g., forestry to agriculture; agriculture to urban area) and land-cover modification (e.g., ecosystem degradation or restoration) also affect multiple systems.” (Section 1.2.1)
Other factors are driving climate change besides greenhouse gases so focusing just on greenhouse gases may only address part of the problem.
“Adaptation has the potential to alleviate adverse impacts, as well as to capitalize on new opportunities posed by climate change. Since the TAR (Third Assessment Report), there has been significant documentation and analysis of emerging adaptation practices. Adaptation is occurring in both the developed and developing worlds, both to climate variability and, in a limited number of cases, to observed or anticipated climate change” (Section 17.5)
We and the natural world are adapting already. We are trying to understand future impacts in social, economic, and natural context that is changing itself. We might also note that other economic changes unrelated to climate change could also impact the future. The United States this year will produce the lowest levels of greenhouse gas emissions in the last twenty years simply because a shift from coal to gas burning power plants. This has been caused not through any governmental action but simply through the operation of the market.
So what are projected impacts?
We might expect that increased temperature and carbon dioxide would affect plant growth. The report says production of cereals may decrease in low latitudes but may increase in mid and high latitudes for the lower range of temperature change. For the higher range of change, it predicts a decrease but the basis for this is shaky since advances in agricultural technology and new crop varieties could easily offset any negative impact to crop yields. In actuality, the extension of growing range further northward would seem to argue actually for the prospect of increased yield for the world as a whole.
We might experience an increase in extreme events as a result of warming. This is the so-called loaded dice scenario. Suppose, for example, a given area is hit by a category 5 hurricane on average once every 50 years. Under the loaded dice scenario, global warming might cause this rate to become more frequent, say once every 40 years. The long-term historical record on extreme events is poor so proving this scenario is almost impossible. We are mostly left with models to gauge whether there is any real effect of this sort and how great it might be. Assuming it is real, does the rate go from once every 50 years to once every 45 or once every 10? This is largely guesswork. Of course, every time we have a busy hurricane season or a hot summer, this argument gains currency in the press; but, it is impossible to attribute any actual hurricane or other weather event to global warming. It stands to reason that higher average temperatures will result in more periods of high temperatures (heat waves) but how high and how many are less clear. However, the magnitude of the impact of extreme events on us is clearly within our power to control. We do not have to build on beaches. We can create barriers to lessen the impact of hurricane winds. We can manage water better to cope with drought
Sea levels will definitely rise as a result of global warming but how much? As sea temperatures rise, the water expands to occupy more space resulting in an increase in sea levels; however, since the oceans are a huge and water conducts heat less well than air sea temperature rise will lag behind land surface temperature rise. The IPCC predicted range is largely based on the effects of thermal expansion; however, a recent study found that much of sea level rise in the last several decades attributed to thermal expansion actually can be attributed to agricultural runoff – pumped groundwater for agricultural purposes making its way to the oceans. The melting of the Arctic ice cap might become an annual summer event but its effect on sea level is largely insignificant because the ice is floating in the water already. The Antarctic ice pack has actually been increasing in extent in the last several decades. The Greenland glaciers are mostly land-locked so only the most extreme scenarios, not predicted by the IPCC, would cause a major meltdown. The glaciers in Europe and other places have been declining since the nineteenth century before the accelerated increase of green house gases into the atmosphere and the decline is caused more by reduced precipitation than temperature increase. All in all, sea levels will rise and this will adversely affect small islands and low-lying countries such as Bangladesh; however, the sea level will not rise equally in all areas and some areas may be more affected than others. Once again we are left mostly with models to assess areas that might be most affected. While the most adversely affected are likely to be deficient in the economic and technological resources to adapt to the changes, the Netherlands has shown us that we can construct solutions to rising sea levels.
The 4th report seems to make some claims regarding water resources, but on closer examination they seem highly qualified and tentative. The report specifically states it finds no evidence of global warming effect on floods, ground water, water, quality, erosion, or irrigation demands. It predicts greater snow cover in the upper latitudes but decreasing snow cover particularly in Spring elsewhere. In fact, most of the claims of global warming effects rely on a variation of the loaded dice scenario. Increased temperature results in increased evaporation and a speed up of the hydrological cycle. This results in increased variability with more rain in some places and some seasons and less in others. Many regions of the world experience periods of greater wetness and dryness. Where I live in the Southeastern United States, we have had in recent years periods of drought and periods of heavy rain. A man-made lake north of Atlanta set a record low in 2007. This was in part the result by improperly calibrated gauge that caused the Army Corps of Engineers to release too much water in the midst of a drought. However, by 2008, water levels were at record high levels from heavy precipitation. Although the report suggests these cycles might increase, once again though we do not know by how much and periods of drought and wetness seem to be the historic norm for this region. At any rate, the impact of any increase can be mitigated by improved water management which must happen anyway to accommodate the economic growth of the region. The drought with greatest human impact is the ongoing drying in sub-Saharan Africa. There is much evidence that long droughts in this region have been the norm for the last several thousand years too. Droughts might intensify in this region with global warming but, in the absence of global warming, they would not go away.
What about effects on biological diversity? With global warming, the habitability zones of species that need warmer temperatures to survive would likely move toward the poles and to high altitudes. This could conceivably squeeze plants and animals at the higher latitudes and altitudes into smaller areas. Increasing or decreasing precipitation will likely affect some species adversely. Clearly there will be winners and losers just as there always has been throughout Earth’s history. The geologically recent loss of much diversity, however, began well before any recent effects of global warming have been felt and can be attributed greatly to human activities, but not global warming. Wherever humans migrated around the world, we killed off the large mammals and cleared forests. In so doing, we have destroyed ecosystems. Many marine environments have been over fished or polluted with agricultural and human waste. We have a problem with diminishing biological diversity but global warming is a small part of it.
Finally the 4th report has a series of even more speculative potential effects of global warming. These include increased conflict, mass migrations, and increases in disease rates. These speculations, however, are mostly based on the already tenuous speculations regarding loaded dice. It stands to reason that some small islands may need to be evacuated if sea level projections actually pan out. Beyond that, most of the rest is speculation built on speculation. Any changes in disease rates could be mitigated by medical technology and improvements in sanitation and provision of clean drinking water. The causes of war and conflict are complex and human history prior to global warming could hardly have been said to have been an era with no war or conflict.
The projected effects of warming are complicated and not necessarily all negative. Even projecting the effects of sea level rise is complicated. Some of the often attributed effects of warming, such as a decrease in biological diversity, are probably more affected by a multitude of other factors, mostly human related but not related to greenhouse gases. Many of the other projected effects, even if they have a potential to occur, might be counter balanced by human adaptations and technology.
So summing up these projected impacts, if they come about, what do we have?
- An exacerbation of problems already caused primarily by human mismanagement and over consumption of environmental resources. Shouldn’t we address our mismanagement first before we worry about climate change?
- Problems which can be mitigated by technology that most adversely will affect poor countries with less economic and technological resources. Don’t these countries need improved access to modern sanitation, medical, and agricultural technologies anyway?
- A sea level rise that may require evacuation of people small islands and low-lying areas – one fairly unequivocal effect that might be costly to remedy through technology and that could disrupt people in these areas.
What clearly comes out from all of this is not that our big global crisis is climate change. Our problem is an irrational consumption of resources of all sorts – fossil fuels, , water, and land – combined with vast inequality in the distribution of wealth that leaves poorer countries with fewer resources to adapt to changes whether caused by global warming or other things. Global warming caused by greenhouse gases, assuming it exists as we have in this exercise, is but a part of the bigger problem of global mismanagement of the planet. Reducing greenhouse gases while we still pillage the Amazon, pollute the oceans, and leave millions impoverished and malnourished the Third World will do far less to make a world a better place than would be addressing the real problems directly. Even if we reduce or eliminate human caused climate change, the climate and the world will still change. Nothing will stand still. The future will be better if we reduce our impact on the Earth in all ways, not just reduction of greenhouse gases. This will in part require that developing countries obtain greater access to the economic and technological resources they need.
In this situation, does it even make sense for humans to try to do anything to mitigate the effects of global warming?
I am not even going to address heroic measures such as space mirrors or ocean fertilization. Aside from the extreme unlikelihood of ever obtaining international agreement and financing on such planetary engineering , the potential for misjudging the magnitude of the effort required to have any real effect on climate or underestimating the potential damage of unintended consequences is too great. We could easily overshoot and plunge the world back into a glacial period, a consequence which would be far worse than any but the most extreme of global warming scenarios.
One might argue that given the unknowns about climate and possible tipping points that it would be better to err on the side of caution and reduce greenhouse emissions. I am somewhat sympathetic to this view. However, from this point forward, the main source of greenhouse emissions may be the developing world. Without forcing the developing world to change their consumption and utilization patterns we will likely see little impact on the overall trend of greenhouse gases. Yet forcing the developing world to curtail their greenhouse gas emissions could result in delay in the economic and technological progress that could allow these countries to cope better with the changes of global warming. In other words, the developed world could reduce its costs in dealing with global warming at the cost of the increasing the vulnerability of the developing world.
In my previous post, I arrived at a concept of life that had as a key element the consumption of order from the environment to create the order that is life itself. Humans of all life on Earth are the most profligate consumers of order. We by far have more effect on life on Earth than any other species. Ultimately, however, life on Earth is doomed. The free ride we are getting from a stable sun pouring its daily energy down on us and the internal heat from our planet, still warm from its creation billions of years ago, will not continue forever. Some believe that we or those who follow us will at some point will need to dismantle literally our entire planet to gain the resources we will need to ensure our own survival.
When we approach the time when the free ride is over, humans may have to destroy life on Earth to continue to exist, but that time is far in the future. In the mean time, we must find a way forward. This requires more technology not less. We might hope that much of that technology will reduce our impact on other life and make more wealth for all humans. Whether global warming is a serious problem or not, the most enlightened action for developed countries would be investment in low impact technologies and making sure those technologies are given to the developing world. These technologies go far beyond solar cells and battery-run vehicles and include such things as birth control, sanitation, and improved agricultural practices. We need to focus not just on climate change but on the broad range of human impacts. This will in the end increase the wealth of everyone.