In seeking to understand climate risks, modeling of worst-case “business as usual” paths put the world on a path to 5C (five degrees celsius) / 9F (nine degrees fahrenheit), or more, warming within the lifetimes of people on earth today. Well, their lifetimes if they survived the enormity of climate catastrophes and disruptions that warming would create. Primarily due to the renewables (and efficiency and …) revolution, those worst-case scenarios have become increasingly unrealistic and even unhelpful. The high-end scenarios are more in range of 3C (<5F) and, more realistic extrapolations of technology progress lead to <2.5C (without additional, significant policy initiatives). Good — even if inadequate — news that warming won’t be nearly as bad as quality analysis. And, good news that it has been human actions that have made these changes. (E.g., after creating the problem we, humanity, actually have agency to address the problems we’ve created.)
However, despite that good news, the reality is that humanity has changed the climate through (primarily) fossil-fuel burning and, no matter the efforts to reduce and reverse the carbon pollution, humanity is already facing climate catastrophes that will worsen in the years and decades to come. And, at the same time modeling is showing less drastic temperature increases in the century to come, improved scientific knowledge and understanding (due, in part, to real-world events) makes clear that the impacts of lower temperature increases will be more significant and dangerous than what was modeled just a few years ago.
The Washington Post‘s Scott Dance’s A new climate reality: Less warming, but worse impacts on the planet provides an excellent half-page discussion of this.
Accelerating solar and wind energy adoption means global warming probably will not reach the extremes once feared, climate scientists say.
[Editorial note: “Scientists say …” is a horrible journalistic editorial practice. While, perhaps, true this really isn’t truthful. “Say” is a rather soft word that, often, in common parlance is used to question implicitly and/or undermine statements. (“He said, she said …”) Like writing “scientists believe” rather than “scientists conclude”, writing “scientists say” moves this away from conclusions based on research and analysis into a softer conceptual world.)
At the same time, recent heat, storms and ecological disasters prove, they say, that climate change impacts could be more severe than predicted even with less warming.
The Optimistic-Pessimist that I am: Optimism driven by clean tech fostering less severe temperature increases tempered by pessimism about the impacts of any temperature increases.
Researchers are increasingly worried about the degree to which even less-than-extreme increases in global temperatures will intensify heat and storms, irreversibly destabilize natural systems and overwhelm even highly developed societies. Extremes considered virtually impossible not long ago are already occurring.
Scientists pointed to recent signs of societies’ fragility: drought contributing to the Arab Spring uprisings; California narrowly avoiding widespread blackouts amid record-high temperatures; heat waves killing tens of thousands of people each year, including in Europe, the planet’s most developed continent.
It’s an indication that — even with successful efforts to reduce emissions and limit global warming — these dramatic swings could devastate many stable societies sooner, and more often, than previously expected.
Dance continues with some good discussions of, for example, the risks of weather extremes’ impacts even in a less (horrifically) extremely heated world climate.
While, in many ways, a good article there is a significant and glaring gap that is all too often glossed over in discussions about climate change. No matter what humanity does related to emissions, even a magical net zero tomorrow and achieving a net-negative global society by the day after tomorrow, we face inexorable — and accelerating — sea-level rise for the coming decades (and, sadly, likely centuries). And, counter to human action and increased knowledge and improved modeling reducing the forecasted future temperature increases, improved understanding is increasing the likely (and, for planning purposes as nearly as important, potential high-end) sea-level rise that humanity will face within the coming decades and century (within the timeframe of things already and being built today).
As John Englander of the Rising Seas Institute has laid out clearly in High Tide on Main Street and, more recently, Moving To Higher Ground: Rising Sea Level and the Path Forward, the IPCC projection of three feet of sea-level rise by 2100, as a worst case, was/is simply unrealistic and derives, in no small part, in explicit leaving out of key sea-level risks from the forecasting due to modeling difficulty. (The “Antarctica Asterix”: potential sea-level rise from Antarctic ice sheet melting is simply left out due to uncertainty about how to model this.) Rather than three feet by 2100, that three feet is quite possible (maybe even probably) by perhaps 2060 and 7-10 feet likely by 2100 with a viable worst 2100 case perhaps more in the range of 20 feet than 3.
The rising seas, as John eloquently discusses, will have significant impacts on geography, human geography, and human civilizations. There is a useful adage about climate change: humanity faces three choices: address (mitigate by reducing emissions), adapt (invest to deal with the changes), and suffer (the consequences). Investing in the first is cheaper, more effective and the need for the second which is critically for reducing the extent and nature of the third. Reality is that all three will occur, the question has been the balance between the three (and decades of delayed and inadequate efforts to address climate change have driven increased need for adaptation and worsened today’s and tomorrow’s suffering). When it comes to the Rising Seas, the reality is that while mitigation of emissions is critical for where sea level rise will peak a century or centuries into the future, the key issue is our choices and actions between adaptation and suffering in the decades (and centuries to come).
Regrettably, around the world, there continues to be massive investments in threatened area that either seems utterly oblivious to the inevitability of sea-level rise or, nearly as bad, incorporates unrealistically optimistic (or, perhaps, not nearly pessimistic enough) projections of future sea-level rise.
Every day that passes with infrastructure investments in at-risk areas without adequate addressing sea-level risks worsens the suffering to come. While there are numerous reasons this occurs, one key one is the near absence from public understanding and discussions that [to paraphrase auto advertising] ‘tomorrow’s sea level isn’t our father’s sea level’. The seas are rising … no matter what we do. Until, and unless, we understand this and incorporate it into society’s planning and investments, tomorrow’s suffering will be (far) worse than it needs to be.