Earth Day 2023 and Global Solidarity

David P. Turner / April 16, 2023

Earth Day 2023 (April 22) is the 53rd anniversary for this annual gathering of the global tribe.  Historically, it has been an opportunity to protest the decline in environmental quality and to envision a sustainable relationship of humanity to the rest of the Earth system.

So, let’s review three environmental trends of particular concern in 2023 and three pointers to the possibility of a sustainable Earth system.

Three concerns.

1.  2023 is shaping up to be an El Niño year.  Ocean circulation in the equatorial Pacific Ocean will slow, which means less heat removal to the ocean interior by downwelling water in the western pacific and less delivery of cool upwelling water in the eastern Pacific.  Global mean temperature will tick up a bit beyond the usual expectation.  There is speculation that 2023 will be the warmest year on record.

2.  Sea ice extent will continue to decline at both poles, which is part of the snow/ice albedo positive feedback to global warming.

3.  Greenhouse gas concentrations will continue to rise.  The annual increase in methane concentration is especially worrisome because the increase has been relatively large in recent years, a consequence of rising emissions from both the global energy sector and biosphere sources.

Three trends to be hopeful about.

1.  The International Energy Agency recently reported that 2023 will mark a step-change upward in the public and private financing available to support the global renewable energy revolution.  The official theme of Earth Day 2023 is “Invest in Our Planet”.

2.  The proportion of land and ocean area in some sort of biodiversity protection status continues to rise.  A 2022 UN biodiversity conference set a goal of 30% by 2030.

3.  Stratospheric ozone continues to regenerate in response to the global regulatory process associated with the Montreal Protocol.

There are endless issues within countries and between countries for humans to argue and fight about.  But recent anthropogenically-driven changes in the global environment are something we all have in common, and something that must be addressed collectively.

In the near term, the growing incidence of extreme weather events associated with anthropogenic climate change negatively impinges on the quality of life of a vast number of people around the planet.  On a decadal time frame, sea level rise will come to displace hundreds of millions of people.  At the scale of a century or more, on-going climate change may set off a cascade of positive feedback mechanisms that will drive the Earth system to a new state inimical to an advanced, high technology, global civilization (the Icarus Scenario).

There are many impediments to becoming a global “we” that will work collectively on global environmental change issues.  But Earth Day, as the largest recurring secular celebration in the world, is an occasion to think anew and commit to opportune joint initiatives.

The Icarus Scenario

Jacob Peter Gowy’s The Flight of Icarus (1635–1637), courtesy of Prado Museum

David P. Turner / February 26, 2020

The future invades the present much more so in recent times than was the case in previous generations.  That’s because the global human enterprise (the technosphere) has initiated an era of global climate change – with potentially catastrophic impacts on future generations.  Thus, humans must now worry more about the future than might otherwise be the case.  While we still have time, humanity must alter course – we must redesign the technosphere.

Earth system scientists have a responsibility to discern coming changes to the Earth system as clearly as possible, and to evaluate potential mitigation strategies.  The time horizon of these scenarios for global change are commonly on the order of a century, or perhaps several centuries.  But examining scenarios that play out over hundreds to thousands of years is also necessary.

In the course of writing a book about global environmental change, I developed a rather dystopian long-timeframe Earth system scenario.  I call it the Icarus Scenario.  This story of Earth’s future is based on emerging Earth system science knowledge about past episodes of drastic global change over the course of geologic history.  On multiple occasions, tectonic movements have initiated periods of massive greenhouse gas emissions (sound familiar?) that led to strong global warming, followed by major alterations in ocean circulation and chemistry, as well as profound changes in the biosphere (including mass extinction events in some cases). 

Humanity might now be initiating the next iteration of that sequence, and the Icarus myth seems an appropriate referent.  Icarus was the figure from Greek mythology who, with his father, constructed wings of feathers and wax.  His father warned him not to fly too close to the sun for fear of melting the wax, but Icarus got carried away with the joy of flight.  He indeed flew too close to the sun, his wings disintegrated, and he crashed to his death on the ground.

A contemporary version of this myth might be manifest as the on-going build-out of the technosphere (with associated greenhouse gas emissions), warnings by scientists about the possibility of overheating the planet, continued fossil-fuel-based technosphere growth driven by an exuberant market economy, and global warming sufficient to push the Earth system through a series of tipping points that catastrophically warm the planet.  Recent geophysical observations suggest the risk of initiating that sequence is increasing.

We can’t of course know the future.  But there are several compelling reasons why we as a global collective should grapple with the Icarus Scenario.

It is likely that the wealthiest people in the world will be able to largely insulate themselves from impacts of climate change over the next generation or so.  Consequently, supporting societal investment in mitigation climate change (e.g. the Green New Deal) may not be a high priority.  However, if their legacy will amount to nothing in a somewhat longer perspective, they might pitch in more vigorously (thanks Jeff Bezos!).

The Icarus Scenario also strengthens the rationale for investing in climate change mitigation as soon as possible to reduce the possibility of passing a threshold and being unable to reverse the trajectory of the Earth system towards catastrophic warming.  The precautionary principle is more readily invoked as the magnitude of a threat increases, and the Icarus Scenario is the ultimate threat.

Being an inveterate optimist, I also formulated in my book a long-term Earth system scenario in which the technosphere builds a sustainable relationship with the rest of the Earth system.  My Noösphere Scenario (pronounced like noah-sphere) assumes cultural evolution towards a high technology global civilization that self-regulates to avoid overheating the planet and consuming the biosphere.  The root word nous refers to mind – Earth becomes a planet organized by collective thought.

Recommended Audio: Epilogue from Everest motion picture (Dario Marianelli)