Climate change and the Paris agreement
- In Mathematics, Science & Technology
- 02:54 PM, Sep 20, 2017
- Ananth Natarajan
On 12 December 2015, 195 countries signed the Paris climate accord marking an unprecedented consensus on climate change after years of effort. On June 1, 2017 President Trump announced that the United States will cease to participate in the agreement. India and other developing countries, which will have to incur the most cost for adhering to it, however stayed on.
In this context, let us try and understand the issues of climate change, the ability to influence it and the cost of such efforts
Complexity of the Earth’s climate systems
The arguments made about climate change in public discourse grossly simplify a complex topic about which there are no certainties, only probabilities of occurrence.
The weather patterns in the world are subject to many factors acting in concert with each other, many of which change over long and differing periods of time. The circulation of air, water in the oceans, plate tectonics (changes in the position of continental plates affect ocean current and air flow), and the amount of greenhouse gases in the atmosphere are all critical to the state of weather and the state of the climate. A small change is of these factors leads to big changes in the resulting weather patterns. Greenhouse gases play an important role is sustaining life on earth. Without these gases trapping heat, the earth will be too cold to support life as we know it. Average temperatures on earth have been far colder and also far warmer than now at different geological periods.
Beyond this there are other factors that act over longer periods of time. For instance, the Milankovitch Cycles, named for Serbian mathematician and astronomer Milutin Milankovitch, is very important to understand climate change. These cycles have been correlated with glaciation periods in our current ice age. Cycle one is changes in the earth’s eccentricity, which is the shape of the Earth's orbit around the Sun. These changes affect the amount of solar radiation reaching the earth and the period is about 100,000 years. The tilt is the earth’s axis accounts for seasons on earth, ice on the poles and variation of weather between hemispheres. This axis oscillates between about 21.5 to 24.5 degrees over a period of about 41,000 years and is the second Milankovitch Cycle. The third cycle is the change in the Earth's precession. The Earth's slow wobble as it spins on axis has a period of about 23,000 years.
It might be interesting to know that we live in an ice age. The Quaternary ice age is the 5th ice age that we know of and started about 2.58 million years ago. Ice ages are divided into glacial and short inter glacial cycles, and the warm temperatures of the current interglacial which began between 10,000 and 15,000 years ago is what enabled humans to settle down, develop agriculture, expand in population, and establish civilization.
While the Milankovitch Cycle help with understanding the onset of glaciation cycles during an ice age, the onset of ice ages themselves separated by 100s of millions of years is not well understood and subject to several speculative theories.
Judging by past glaciation events that have occurred in “our ice age”, the next glaciation cycle could be right around the corner, with profound implications on the continuity of human civilization and the survivability of the majority of the world’s population i.e. “Winter is (could be) coming”. Previous interglacial periods in our ice age have been about 10,000 years long, roughly the length of time of the current interglacial. But while several papers have discussed these issues, there is no certainty about its onset. Interestingly, some climatologists suggest that the present inter-glacial period might be prolonged, and the ice be kept away for a longer time due to human induced greenhouse gas emissions, which implies both that those emissions do have a significant role in global warming and also that these have a net positive role.
The uncertainty in weather and climate predictions
The reasons for uncertainty in weather predictions lie in Chaos Theory, a branch of mathematics that originated with the work on the 3-body problem by Henri Poincaré. It does not refer to the disorder, indeterminacy and high entropy that is implied by the popular definition of chaos. What it actually refers to is that a small change in input conditions to a system of process often produces disproportionately high changes in the output behavior of dynamic systems. Therein lays the difficulty with weather prediction. With a given input a fairly accurate prediction of the weather can be made with today’s weather models and computing power. However a small change in a parameter affecting the weather such as small localized variations in temperature or pressure can change the prediction dramatically. This is illustrated famously by the butterfly effect referring to the possibility of the flap of a Butterfly's Wings in Brazil setting off a Tornado in Texas. Weather is therefore predictable up to only about a week ahead and predictions are made by averaging over probabilities of occurrence.
So while climate change skeptics have a point about the relative scale of human intervention while compared to the scale of the other factors affecting climate, chaos theory points out how a small disruption can lead to profound changes often resulting in unpredictable outcomes. On the other hand, the bulk of climate change believers do not understand the lack of certainty with predicting climate change, and that what we have is from probabilistic projections from short term data combined with analytical models. It is best to be more objective.
As said earlier, it is possible that human induced greenhouse emissions have forestalled a catastrophic global cooling as we approach the end of the interglacial period of the current ice age. This is a possibility that has been seriously but not extensively explored. We cannot definitely say that the last glacial period was the last of the series thus ending this ice age, an outcome highly prone to bias since it is extremely beneficial to humanity.
Climate change predictions
An attempt to distill climate predictions into an “integrated view of climate change” was done by the Working Groups of the Intergovernmental Panel on Climate Change (IPCC). The IPCC was set up by the UN with participation from member governments and produced the reports that support the United Nations Framework Convention on Climate Change (UNFCCC) which lead to the Paris Agreement. They state that:” Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history”. Given the uncertainties with predicting climate these predictions are made with explicitly stated levels of confidence. The uncertainty is thus acknowledged in the summary reports where it is stated that: “Each finding is grounded in an evaluation of underlying evidence and agreement. In many cases, a synthesis of evidence and agreement supports an assignment of confidence. The summary terms for evidence are: limited, medium or robust.” Trends indicating increased land and water temperature and higher sea levels over the last century are correlated with increased greenhouse gas emissions over the same period pointing to a cause and effect relationship.
However, the data used in these reports is extremely short term in comparison with the longer term “natural” and cosmic drivers of climate change discussed previously. How these short term trends which are highly likely to be caused by human influence as documented in the reports will interact with the longer term drivers is not clear.
Considerations guiding future courses of action
While considering the balance of probabilities to look for a future of action, the once that lead to the most positive outcomes with the least certainty would seem more attractive. Curbing Greenhouse emissions seems to be an attractive option. But this option will also have to be weighed against the alternatives to use society’s resources, such as the need to tackle poverty. A given quantity of emission has an aggregate cost associated with its use and a tax (opportunity cost) associated with not using it.
As Professors Paul Samuelson and William Nordhaus say in the introduction to their famous textbook on economics, the fundamental problem of economics is related to the optimal employment of resources that are by their nature scarce. With the limited resources available to society a balance between incurring the cost of curbing emissions and those related to human development goals, while also recognizing that some decisions can further both ends.
There are several considerations for abiding by the Paris protocol. Climate change and sea level rise, ocean acidification etc. can have a severe impact on economies, food production ecosystems etc. The many severe and varied impacts are summarized in the IPCC summary report for Policymakers. Some other considerations that do not have to do with climate change considerations that inform these decisions for a country like India include: reducing the dependence on imported non-renewable energy sources for economic and strategic reasons, reduction of pollutants in population centers etc. There is also the observation that renewable energy technologies are developing at a much more rapid pace compared to other energy related technologies, and it is important for a country to participate in cutting edge industries that appear to have great future potential.
There are also several reasons to not abide by it. And these are relatively harder to find discussed in popular media. First as was pointed out, climate change prediction is far from exact. Then even allowing for global warming and other effects, the benefits of complying with an agreement like Paris has to be contrasted with the benefits of using the same economic resources on other worthy causes such as poverty amelioration and reduction of hunger.
Professor Bjorn Lomborg is well known for his contrarian views regarding the efficiency of investments employed to fight climate change versus employing them on several other development goals. The detailed studies by him and the Copenhagen Consensus Center (CCC) that he leads, point to a minuscule impact on climate change if all the Paris promises are kept at a very high opportunity cost from the foregone human development activities for the same investments. Their projects assessed dozens of development goals and found that investments into keeping global temperature rises below 2C would return less than $1 for every $1 spent, which they rated “poor” compared with other possible investments. At the same time the climate impact of all the Paris promises is minuscule. From their studies: the impact of every nation fulfilling every promise by 2030 would lead to a total temperature reduction of only 0.048°C by 2100. It is pointed that the actual effect of compliance with Paris on global warming is not very significant while the cost especially to developing countries will be very high.
There have been several papers that try to counter many of the CCC’s findings, mostly by trying to raise the estimates for the cost of climate change and making long term assumptions on the progress of “green” technologies for energy production. These debates, on both sides, are based on volumes of data and rely strongly on interpretation and assumptions and it would not be possible to do them justice in the space of this article. But it can safely be said that the argument for directing society’s investments to meet the 2C temperature target from Paris is far from straight forward and a strong case can be made otherwise.
There are some indications that the levelized cost of energy from renewable sources is catching up with that from fossil fuel, even though we are far away from seeing if this will still be the case at the scale needed to make a significant dent in energy demand. Renewable energy inputs such as land and rare earth metals have their own supply bottlenecks that will become apparent with more scale. It is better to allow the market a greater say in determining these efficiencies and bottlenecks. In any case government support is not scalable to the level of energy that is required overall.
For developing countries the cost to be paid is higher since most of their wants are in fact needs associated with basic quality of life indicators such as transportation, electricity, and longevity all of which are correlated with energy consumption. For instance, the GDP per capita of the United States in 2016 was USD 57,467 almost 10 times that of India at USD 6572 (World Bank data). There is a unit of energy associated with every unit of GDP; this is called the Energy Intensity. And while the developed countries have attained a high standard of living from cheap fossil fuel, developing countries still have a long way to close the gap that will entail the consumption of a lot more energy than at present. The per capita emission in India in 2015 was 1.87 Tons_CO2/cap as compared to 16.07 Tons_CO2/cap for the US (from the EU EDGAR emissions Database). GDP per capita has a high correlation to many factors of human wellbeing, longevity, healthcare, education, electricity to name just a few. All this points to the inherent unfairness of attempts to cap CO2 emissions of developing countries at present levels.
Final Thoughts
To summarize, it might appear that staying on course with Paris is perhaps the best possible way under the circumstances, even while looking through the uncertainty surrounding several of the key decision parameters. And it is not easy to come to this conclusion as this is subject to a wide margin of error. To be more certain we have to be guided by a weighted set of probabilities. A cold eye factual assessment of all of these factors will be needed to say this with more certainty.
Such an exercise covering all the factors discussed here seems not to have been undertaken in any systematic fashion. Most studies concentrate only on aspects of the problem. An attempt has been made here to paint a broader picture of the issue with a more comprehensive array of relevant factors. Several of those issues and factors are very uncertain, not well understood and cannot be quantified in a meaningful way. Therefore the ability to cognitively weigh these probabilities and factors to come up with a judgement based decision will still be important. To this end it would be good for the major stakeholders such as governments, with bodies such as the Intergovernmental Panel on Climate Change (IPCC) but also with bodies such as the UN Department of Economic and Social Affairs (DESA), to develop a more comprehensive decision mechanism to guide policy choices.
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