Extreme Weather Events, Social Tipping Points, and a Step-Change in Climate Change Mitigation

David P. Turner / August 12, 2023

Figure 1.  Annual additions of coal-fired electricity generation in recent years. Image Credit.

The rash of extreme weather events and associated impacts on humans around the world in recent years (especially 2023) is setting the stage for radical societal changes at the local and global scale with respect to climate change mitigation efforts.  One recognizable step-change in that direction would be a planet-wide cessation in the issuing of permits to build new coal-fired power plants.

Extreme weather events (droughts, heat waves, fires, and floods) are very much in the news recently everywhere on the planet.  Within the scientific community, these events are understood as part of normal weather variability, but also as attributable in part to on-going anthropogenic climate warming.  This year (2023) is proving to be especially prone to extreme weather events because of an extra boost of warming associated with an El Nino event

Globally, climate scientists suggest that 85% of people have suffered from extreme weather events that are partially attributed to climate change.

Social science research has shown that people respond markedly to their personal experience with weather events.  In the U.S., polls (2022) find that 71% of Americans say their community has experienced an extreme weather event in the last 12 months and 80% of those respondents believe climate change contributed at least in some measure to the cause.  In China and India, recent polls suggest strong awareness about the climate change issue and support for governmental mitigation policies. 

Admittedly, awareness of the issue is much lower elsewhere.  Some countries in Sub-Saharan Africa have relatively high proportions of inhabitants that have “never heard of” climate change. 

Nevertheless, billions of people around the world are making the connection between their personal experience of an extreme weather event and climate change.  Perhaps a new level of political support for mitigation efforts will emerge?

The concept of tipping points is common in the climate change literature, i.e. that distinct large-scale processes such as the melting of the Greenland ice sheet eventually reach a point where strong positive (amplifying) feedbacks are engaged and the process becomes irreversible (on a human timescale).  The concept has also begun to be applied to changes in social systems.  Given widespread changes in personal views about climate change, and perhaps appropriate societal interventions, particular societies and ultimately the global society may tip into a strong climate change mitigation stance.

A clear step-change in the global climate change mitigation effort would be a planet-wide cessation of permits for building new coal-fired electricity generating plants.  Coal emissions contribute about 40% to global fossil fuel emissions.

Tremendous momentum has already built up in that direction based on anti-coal environmentalism and the improving cost differential between coal power and other energy sources (primarily natural gas and renewables).  The U.S. and E.U. do not formally prohibit new coal plants but few have been built in recent years.

The World Bank, the International Monetary Fund, and China’s Belt and Road Initiative are no longer supporting construction of new coal-burning facilities and many countries have made commitments in their Nationally Determined Contribution statements that will require reduction in the burning of coal.

Remarkably, India has recently announced consideration of a policy to prohibit planning of new coal-fired plants for at least the next 5 years.

China is still permitting and building about 2 coal-fired power plants per week.  It is no doubt a big ask for China to adopt a no-new-coal-plants policy.  However, the country is suffering significantly from extreme weather events, from the negative effects of air pollution from coal combustion, and from the interaction of the those two factors.  And China leads the world in production of renewable energy. 

The autocratic style government in China is not conducive to bottom-up social tipping dynamics, but how the Zero-Covid policy was dropped is an interesting case study in social change.  Rumblings within the bureaucracy and multi-city protests appear to have influenced Xi Jinping to make the radical policy shift.  Given its massive contribution to the global total of new coal plants coming on line (Figure 1), if China stopped issuing building permits, the battle would be nearly won.

Two caveats to ending coal-fired power plant construction should be considered.  First is that the global demand for electricity will likely increase in the future because of 1) growth in the global population and increased per capita energy use in the developing world, 2) increasing demand from the conversion to electricity powered vehicles, and 3) wide application of AI technology.  To generate that energy from non-coal sources will be challenging but feasible.  The second consideration is the possibility of Carbon Capture and Storage, i.e. continuing to burn coal but capturing the associated CO2 emissions and sequestering them belowground.  This technological fix sounds good in theory but thus far decades of research and pilot studies do not support that it can be economically implemented at scale.

Across all of humanity, cultural differences tend to build silos around each society – especially differences in language, religion, and degree of technological development.  That isolation has diminished over the course of human development to this point, and with the advent of the Anthropocene we can begin to see humanity as a unified whole and as capable of working collaboratively  on global environmental change issues.

When the world does achieve consensus on ending the construction of new coal power plants, it will be a step-change in the global climate change mitigation effort.  It will also signal a step towards the emergence of a collective humanity, an indication that “we” can agree on, and implement, a path to a sustainable future on Earth.

Peak Carbon Dioxide Emissions and Peak Carbon Dioxide Concentration

David P. Turner / January 11, 2024 (update)

Figure 1.  Projections of CO2 emissions and concentration.  Image Credit NOAA

In 2020, a remarkable speculation circulated in the cybersphere to the effect that global emissions of carbon dioxide (CO2) from fossil fuel combustion may have peaked in 2019.  Considering that recent formal projections generally indicated increasing emissions through 2030 or longer, this assertion was striking.  It matters because CO2 emissions determine the growth in the atmospheric CO2 concentration, which in turn influences the magnitude of global warming.

The atmospheric CO2 concentration is currently around 420 ppm (up from a preindustrial value of around 280 ppm) and is rising at a rate of 2-3 ppm per year.  The consensus among climate scientists is that rapid greenhouse-gas-driven climate change will be harmful to the human enterprise on Earth.  It would be good news indeed if CO2 emissions were on the way down.

Estimates for annual global CO2 emissions are produced by assembling data on consumption of coal, oil, and natural gas, as well as data on production of cement and effects of land use.  The sum of fossil fuel and cement emissions is termed Fossil Fuel & Industry emissions (FF&I).  Land use, land use change, and forestry (LULUCF) is mostly the net effect of carbon emissions from deforestation and carbon sequestration from afforestation/reforestation.  Total anthropogenic emissions are the net of FF&I and LULUCF.  Two independent estimates of CO2 sources and sinks (GCP and IEA) differ slightly.

The suggestion that peak fossil fuel emissions occurred in 2019 held true in 2020 and again in 2021 and 2022, but 2023 saw a 1.1% increase over 2019

Intriguingly, a decline in LULUCF compensated for the increase in fossil emissions such that total anthropogenic emissions remained the same in 2023 as 2022 (11.1 GtC yr-1).  That result may hold in 2024 as well if President Lula of Brazil continues to succeed in reducing deforestation, and global fossil fuel emissions grow only modestly (if at all).

Several specific observations points towards lower emissions in the near-term future.

1.  Global coal emissions declined from 2012 to 2019 but have risen above 2012 in recent years, primarily due to increases in India and China.  However, coal emissions declined 18.3% in the USA and  18.8% in the EU in 2023.  Aging coal powered electricity plants in the U.S. are being replaced with plants powered by natural gas (more efficient that coal) or renewable energy.  Some coal plants have been prematurely retired.  A gradual phase out in global coal consumption is being driven by the price advantage of renewable energy, impacts of coal emissions on human health, and the reluctance of insurance companies to cover new coal power plant construction.  China has agreed to stop financing the construction of coal power plants in developing nations and India has pledged to stop approving new domestic coal plants.

2.  Peak oil use may have occurred in 2019.  Global demand in 2020 fell 7.6% because of Covid-19. It partially recovered in 2021 and 2022 and 2023 but remains below the level in 2019.  Structural changes such as reduced commuting and business-related flying mean that some of the demand reductions associated with Covid-19 have persisted.  Vehicles powered by electricity and hydrogen rather than gasoline are on the ascendancy, sparked in part by governmental mandates to phase in zero emissions vehicles.

3.  Even a near-term peak in natural gas consumption is being discussed.  The GCP budget for 2022 showed a 0.2% decline in gas emissions and for 2023 a 0.5% increase.  Again, the price advantage of renewable sources will increasingly weigh against fossil-fuel-based power plants.  The growing importance of energy security at the national level also argues against dependence on imported fossil fuels.  Ramped up production of renewable natural gas could substitute for fossil natural gas in some applications.

It is likely that the approaching peak in total fossil fuel use will be driven by diminishment of demand rather than lack of supply.

Currently about half of FF&Iemissions remain in the atmosphere, with the remainder sequestered on the land (e.g. in vegetation and soil) and in the ocean.  The land sink is increasing in response to 1) high CO2 enhancement of photosynthesis and plant water use efficiency, and 2) policy driven impacts on land management (e.g. more reforestation and afforestation).

Once fossil fuel emissions begin decreasing and fall by half − and assuming the net effect of increasing CO2 and climate warming is still substantial carbon uptake by the land and ocean − the atmospheric CO2 concentration will peak and begin to decrease.  The year of peak CO2 concentration could be as early as 2040 (see carbon cycle projection tool below).

On the other hand, there is plenty that might go wrong with this optimistic scenario.  As climate change intensifies, the net effect on land and ocean sequestration could be a decline in carbon uptake.  On land, carbon sources such as permafrost melting and forest fires will be stimulated by climate warming.  In the ocean, warming will intensify stratification, thereby reducing carbon removal to the ocean interior.  The steady increase in the ocean carbon sink since around 2000 has stalled in recent years, for poorly understood reasons.  If fossil fuel emissions are not significantly abated in the coming decades, the CO2 concentration could still be rising in 2100 (Figure 1).

Recommended:  Interactive CO2 Emissions and Concentration Projection Tool.