One would think the latest reports documenting the lack of action regarding climate change, the continued and accelerating changes to the oceans and cryosphere, the deteriorating condition of the Great Barrier Reef, and the astonishing decline in avian populations along with the ongoing extinction of numerous other plant and animal species, should serve to focus global attention on planetary change in the Anthropocene.  Unfortunately, it would appear that business as usual will be the most likely outcome of all these reports, despite much wringing of hands, gloomy predictions and opining of pundits, experts and the like. 

A hallmark of the Anthropocene is the observably (much!) higher rate of change in many Earth system processes as compared to “background” rates determined from historical records. This acceleration has been well documented, but very poorly communicated to the general public and largely ignored by decision makers.  Rising concentrations of carbon dioxide, increasing sea and land temperatures, accelerated melt rates of sea ice, permafrost and ice sheets, along with rising sea level, inform us that a critical fork in the road lies ahead.  Ignore these signposts and there will be no opportunity to even make a choice as to which road we take—the decision will have been already made.

With this analogy in mind, I turn to three papers, one written in 1976, one in 2013, and another released this September.  In 2013, James Hansen and 17 other scientists published “Assessing ‘Dangerous Climate Change’:  Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature.”( Dangerous climate change) Their paper documented the continued rise in atmospheric carbon dioxide from fossil fuel combustion, along with the various attendant impacts to Earth system processes, the environment and human health and well-being arising from this accumulation.  The authors suggested that the inertia of the climate system causes it to respond “slowly to this man-made forcing,” complicating policy responses, as well as obscuring the potentiality for irreversible climate change due to slow feedbacks.  Although the rapidity and scale of such changes; e.g., irreversible melting of Antarctic and/or Greenland ice sheets remains unclear, continued combustion of fossil fuels threatens to lock us into this future. 

They argued that the implications of future climate change already “in the pipeline” are thus intergenerational, presenting young people of today with a future they will have had no hand in shaping.  The authors suggested that “(a) scenario is conceivable in which growing evidence of climate change and recognition of implications for young people lead to massive public support for action” based on the expectation of “fairness and justice in a matter as essential as the condition of the planet they will inhabit.” This sounds remarkably like the argument underlying today’s campaign by young people for climate justice. The conclusions of the 2013 paper are stark:  the opportunity to avoid climate disruptions and maintain global temperatures below 2^oC will require “extraordinarily rapid emission reductions” and choosing an alternative energy pathway, a “fork in the road” from a carbon-rich energy path to one that is carbon-free.   

The choice of a “hard energy path” as opposed to a “soft energy path” was outlined more than forty years ago, in Amory Lovin’s seminal October 1976 Foreign Affairs article “Energy Strategy:  The Road Not Taken?” (Soft Energy Paths) in which he outlined the numerous benefits of shifting from a “hard path” of fossil fuels and nuclear power to a “soft path” of efficiency and renewable energy, focused on matching the quality of energy to its end use.  Lovins’ deeply controversial and influential article showed a way forward to an energy future that today bears a remarkable similarity to his original description.  However, despite rapid efficiency improvements, technological breakthroughs and movement along a soft energy path envisioned by Lovins, a key aspect of the soft energy path, deployment of renewables, lags approximately 25 years behind the 1976 projections.  Deployment of renewables must therefore accelerate even more rapidly if we are to move towards an energy future that will avoid the irreversible climate change outlined by Hansen et al.

These choices are now before us, laid out in a September 2019 White Paper from the World Economic Forum, “The Speed of the Energy Transition—Gradual or Rapid Change?”  (The speed of the energy transition) The paper poses the question “Will the global energy transition from fossil fuels to sustainable energy be gradual or rapid?”  The authors suggest the choice of paths will be made this decade, that the two paths are mutually exclusive, and that the choice of business as usual “regrettably … means that the goals of the Paris Agreement will become increasingly unachievable.” 

There are three “signposts” along the path to a Rapid global energy transition by 2030 according to the White Paper: 

(1)  solar electricity at $20-$30 per megawatt hour

(2)  carbon taxes implemented on around half of emissions at $20 per tonne

(3)  three peaks to take place in the 2020’s

            a.  peak demand for new internal combustion engine cars

            b.  peak demand for fossil fuels in electricity

            c.  peak demand for all fossil fuels

If we pass these, the Rapid transition is on track; failure to pass these leads to a future whose socioeconomic  and Earth system dimensions will be dictated by processes humanity has set into irreversible motion.  The chart from Hansen, et al hints at the potential long lags in the climate system’s response to fossil fuel emission cuts: it could take centuries before atmospheric carbon dioxide levels return to “safe” levels of 350 ppm.  

The chart below from BerkelyEarth shows the path to 1.5^oC is only a decade or so distant, if current trends continue.  The chart shows a ten-year moving average of the Earth’s surface temperature, plotted relative to the average temperature from 1850-1900.  At the current rate of increase, 1.5^oC above the 1850-1900 average will be reached by 2035. 

According to Hansen et al., warming will reach 1.5^oC and “stay above 1.0^oC until 2400 if emissions continue to increase until 2030.”

Perhaps Greta Thunberg said it best in her September 23 address to the United Nations:

“For more than 30 years, the science has been crystal clear. How dare you continue to look away and come here saying that you’re doing enough, when the politics and solutions needed are still nowhere in sight…The popular idea of cutting our emissions in half in 10 years only gives us a 50% chance of staying below 1.5 degrees [Celsius], and the risk of setting off irreversible chain reactions beyond human control…Fifty percent may be acceptable to you. But those numbers do not include tipping points, most feedback loops, additional warming hidden by toxic air pollution or the aspects of equity and climate justice…You are failing us. But the young people are starting to understand your betrayal. The eyes of all future generations are upon you. And if you choose to fail us, I say: We will never forgive you. 

We will not let you get away with this. Right here, right now is where we draw the line. The world is waking up. And change is coming, whether you like it or not.” (Thunberg Transcript)

Image: Jon Tyson on Unsplash