I never had a question about what I wanted to do next. For me, ideas are cheap and execution is what matters. However, if by sharing my experiences and thoughts I can make a contribution, I am happy to do so. The “For the Sake of Days Yet to Come” article series intends to do exactly that. It contains my understanding and perspective regarding climate change, potential strategies to address it and how I can personally contribute. I hope to provide a concise description of climate change risks and their mitigation strategies to anyone who is unaware about it. For those who are already familiar with the topic, these articles may provide a slightly different perspective. Hopefully, this perspective may help the reader position oneself for making the most meaningful contribution towards addressing the problem of climate change.
1. Gravity of the Problem
As is probably known by most, climate change poses risks for both man-made and natural systems. The key risks identified with high confidence by the Intergovernmental Panel on Climate Change Working Group II range from irreversible loss of ecosystem services* to increased malnutrition and loss of life. The severity of the risks depend on the vulnerability of human and natural systems, climate-related hazards and their intensity. Examples of climate-related hazards are: precipitation patterns and intensity changes, increased frequency and intensity of extreme heat, novel hazards with which local communities are not used to dealing, sea level rise, heating and acidification of the oceans .
In order to mitigate climate change-related hazards, stabilisation of greenhouse gas (GHG) concentrations is necessary . While around one third to half of the CO2 released is absorbed by land and oceans over decades, the rest stays in the atmosphere for hundreds of years . This means that, in practical terms, the stabilisation of GHGs requires an almost complete elimination of GHG emissions.
The climate change target for stabilisation, as stated in various settings, most notably in the Paris Agreement, is to remain below 2°C of warming compared to the preindustrial era. Surpassing 2°C warming significantly increases the likelihood of the climate-related hazards previously mentioned. On top of that, higher global temperatures can activate natural cycles that accelerate global warming, such as the release of carbon trapped in frozen soil and the seabed . In order to have a 66% chance** of staying below 2°C warming, atmospheric concentrations of CO2 have to be kept lower than 450ppm .
Unless global GHG emissions peak in 2020 and then decrease by more than 3% per year , achieving the 450ppm target is very unlikely. Considering that the energy demand is growing, especially in developing countries, the rate of decarbonisation has to be much faster. Thus, to consider the target of staying below 2°C as realistic one has to be very optimistic. How optimistic? What does 3% per year mean? As a reality check, try the following: go to the nearest highway and then look at the sheer number of cars for a moment. Think about all the people in these cars, their dreams, concerns, daily lives, habits. Do you believe that in ten years half of them will use another mode of transport? Will they drive electric cars or use fuels for the cars that will be net zero carbon from a life-cycle point of view? I do not.
Climate change may cause havoc on a global scale, and the changes needed to avoid it seem to be enormous. As one professor stated in regards to the 2°C target: “it is scientifically insufficient and politically impossible”.
*Ecosystem services are services which we get from the environment for free. If degraded, these systems can be replaced by man-made ones, however that would be extremely expensive. Examples of such services include purification of water in the natural water cycle and the natural formation of soil.
**Due to limitations of current scientific understanding and the inherent unpredictability of some natural phenomena, a confidence interval is given to quantify the likelihood of an event happening
2. The Fragility of the Desired Climate System State
If staying below 2°C warming is not likely, is there any point in trying to reduce GHG emissions? I believe there is.
Increasing GHG concentrations further than 450ppm makes numerous hazards more likely and more severe. Moreover, mitigation in a warmer planet may be more complicated due to “positive feedback” effects. “Positive feedback” in the global warming context refers to increased warming due to natural processes activated by prior warming***.
I am not able to elaborate authoritatively on details about how positive feedback would affect mitigation, however to give a general overview, it is important to understand that the climate as a complex system does not change linearly. The climate can stay relatively unchanged while increasing some forcing factor, such as an increase in average temperatures. However, after passing a so-called ‘tipping point’, the system can abruptly change its state. For example, ice sheets may retreat slowly year by year, but at some point, after losing a large enough ice mass and having a large enough surface darker than white ice, further melting can appear abruptly and be irreversible****. Furthermore, there is no single known tipping point which separates today's world and the one of Mad Max’s dystopia. There are a number of ecosystem state changes, such as coral bleaching, that have already happened due to recent warming. Many more are expected. The most dangerous situation would come to pass if some of these changes would result in a chain reaction. Thus, even if we go above 2°C and do a lot of irreversible damage we can still avoid more. Even if chances of stabilising climate change at 2°C or even 3°C of global warming are small, the real effort has to be given due to the sheer scale of negative impacts that can be avoided.
***Examples of feedback effects: change in albedo due to ice melting in the arctic (dark water absorbs much more solar energy than white ice); release of methane from melted permafrost.
****Look up the ‘abledo affect’ for more details.
3. The Goal
In general the goal of climate change mitigation could be stated as:
“Stabilisation of GHG concentrations to the lowest possible levels to reduce risks of irreversible degradation of ecosystem services and institutional resilience to adapt to these changes.”
However, it begs the question of what the “lowest possible levels” of GHG concentrations are and what risk levels are acceptable. A numerical value like 2°C gives an objective goal to be pursued. Failing this target will incur sizable adaptation and increase mitigation costs. The 2°C target could be viewed as a defensive line an army is trying to hold. Failure of holding the line can be followed by retreat to the new line. This, however, results in lost territory, reduced countries' fighting ability while the enemy is still able to advance. The only gains from retreat are buying time and, in some occasions, stronger defensive position. Most countries may be rich and stable enough to “retreat” far beyond 2°C, enduring and mitigating risks of a very large level of warming. However, this could result in significant degradation of the natural environment, loss of life, high economic costs of adaptation and decreased standard of living. Therefore, 2°C needs to be pursued while it is still in the realm of possibilities.
This is easier said than done. The next article in this series will explore possible strategies to achieve this goal.
In Collaboration with The CommUnity Post
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T. D. Q. G.-K. P. e. a. Stocker, “Technical Summary. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change,” Cambridge University Press, Cambridge, New York, 2013.
P. C. S. G. B. L. B. e. a. Ciais, “Carbon and Other Biogeochemical Cycles. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change,” Cambridge University Press, Cambridge, New York, 2013.
R. P. a. L. Meyer, “IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change,” Geneva, 2014.
“www.youtube.com,” [Online]. Available: https://www.youtube.com/watch?v=FxouKBGGtRY&t=3s. [Accessed 25 12 2016].