Failed Legacy Climate Strategy – IPCC 2023 Synthesis Report Review
by Bruce Melton
First published in the Austin Sierran on April 7, 2023
Summary: IPCC says climate change is worse, but they do not recognize tipping activation. The say emissions reductions and carbon dioxide removal must be faster and greater, but they still think further warming to 1.5 degrees C or even warmer is safe, without even considering tipping activation will likely become irreversible by mid-century. The continue to insist there is a carbon budget when tipping activation self-fulfills to irreversible feedback emissions with no further warming. Future emission that create future warming remain their focus, regardless that current warming has activated tipping systems responses. There are no new restoration scenarios. All 1,202 scenarios evaluated have a minimum temperature target of 1.5 degrees C above normal or warmer.
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The Intergovernmental Panel on Climate Change (IPCC) has released its fourth and final report of the Assessment Report 6 series (AR6). The bottom line, “There is a rapidly closing window of opportunity to secure a liveable and sustainable future for all (very high confidence).” The report continues to advocate for further warming with a 1.5 degree C warming above normal target where we have warmed to 1.1 degrees C today and where, “Deep, rapid and sustained mitigation and accelerated implementation of adaptation actions in this decade would reduce projected losses and damages for humans and ecosystems (very high confidence).” Also continued is the suggestion that natural systems can play a significant role in emissions reductions. They continue to assert that air capture of carbon dioxide is expensive and can only ramp up to do so much and that the extremely complicated solutions of emissions extinction we have been attempting for 30 years are plausible and can make a difference. Yet, they say our time is limited to reduce emissions, as they have been saying for over 30 years. In 2019 IPCC says we emitted 59 gigatons of greenhouse gases. In 2010 we emitted 52 Gt, and in 1990 we emitted 37 Gt.
Also, IPCC continues to suggest that impacts are locked in, that we cannot go back. This is almost completely false and the reason is not intuitive. IPCC evaluates the past 7 years of climate science with future projections based on modeling of 1,202 scenarios considered in the AR6 series of reports. None of these scenarios have a warming target of less than 1.5 degrees C above normal. All are assumed futures (this is what a scenario is after all) that consider an imaginary future where greenhouse gases increase or decrease by some imaginary amount, our population changes by some assumption, we decarbonize our culture by some rate, natural systems can continue to remove climate pollution from the sky regardless of how badly they are compromised from warming, negative emissions are ramped up based on assumed time to market from revenue generation or other assumed ramp up times that are all based on having until the year 2100 to achieve success. Particular troublesome are that abrupt changes and climate tipping responses are not factored in to any of these 1,202, 1.5 degree C or warmer scenarios.
Impacts Are Locked In Unless We Restore Our Climate Back to Within the Evolutionary Boundaries of Her Systems
The takeaway then is, of course impacts are locked in if we continue to warm. What we are not allowed to consider though, because of the scenarios that must be present to model the future, is what happens as tipping collapses continue to grow, and what happens when tipping responses become truly irreversible after passing the point of no return (Hansen 2017), where even if the warming is removed the systems collapses continues until complete?
The answer is simple, but nowhere to be found in IPCC reporting. If we cool Earth to below the temperature today, as Sierra Club now supports with our “less than 1 degree C warming target,” we can return our Earth systems back to within their evolutionary boundaries so they can self-restore. It is these evolutionary boundaries and abrupt and irreversible changes that have already begun that do not self-restore unless the warming that caused them is removed, that are the keys to unlock IPCC’s statements of irreversibility.
The synthesis report continues to suggest abrupt and irreversible changes are yet in our future, “The likelihood of abrupt and irreversible changes and their impacts increase with higher global warming levels (high confidence). As warming levels increase, so do the risks of species extinction or irreversible loss of biodiversity in ecosystems such as forests (medium confidence), coral reefs (very high confidence) and in Arctic regions (high confidence). Risks associated with large-scale singular events or tipping points, such as ice sheet instability or ecosystem loss from tropical forests, transition to high risk between 1.5°C–2.5°C (medium confidence) and to very high risk between 2.5°C–4°C (low confidence). The response of biogeochemical cycles to anthropogenic perturbations can be abrupt at regional scales and irreversible on decadal to century time scales (high confidence). The probability of crossing uncertain regional thresholds increases with further warming (high confidence).” The critical piece of thinking that must be repeated is that once a collapse begins, it does not self-restore unless the cause of the collapse is removed. This is standard tenth grade science. When a system’s boundary conditions move beyond that system’s evolution, the system collapses so new species and mechanisms can re-evolve that are tolerant of the new conditions.
The Amazon Has Flipped to Emissions of Greenhouse Gases
Currently we see the Amazon has flipped from carbon sink to carbon source, emitting and not storing greenhouse gases. This has happened because Earth is now warmer than the conditions where the Amazon evolved and it is collapsing so it can re-evolve with new species and mechanisms tolerant of the new conditions. The same thing is happening in tropical forests globally, in high altitude and high latitude forests, and with permafrost collapse.
Each of these systems is now emitting greenhouse gases in feedback loops that do not self-restore unless the warming that caused the collapses to activate is removed. The focus of climate pollution mitigation today, after over 30 years of trying to reduce emissions and failing, must be to remove climate pollution from our sky before ongoing collapses actually do become irreversible. Attempting to continue with emissions reductions cannot hurt, but the bottom line is that we must rapidly draw down atmospheric greenhouse gases to reduce warming before the point of no return arrives.
See the full IPCC Synthesis Report and Executive Summary Here > > > |
