Tag Archives: climate change

Six More Rationales for Supporting a Renewable Energy Revolution

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David P. Turner / May 12, 2022

The threat of global climate change points to the dire need for a renewable energy revolution in which energy from combustion of fossil fuels (coal, oil, natural gas) is rapidly displaced by energy from renewable sources (wind, solar, geothermal, hydro).  Research by engineers and economists attests to the feasibility of building a global energy infrastructure that runs on renewable energy.  However, forward looking policies must be designed and strong political will must be generated.

In a heavily politicized environment such as Washington D.C., policies are much more likely to get implemented when they are supported for more than one reason.  The underlying mechanism is that with powerful forces aligned for and against any given policy proposal, several constituencies  ̶  each supporting a desired policy for a different reason  ̶  must coalesce to overcome opposition.

Clearly, the strongest rationale for a global renewable energy revolution is to reduce greenhouse gas emissions and mitigate climate change.  But here are six additional rationales that should motivate leaders and legislators to support renewable energy policies.

1. Geopolitical strategy.  The Russian invasion of Ukraine has thrown a spotlight on the vulnerability of nations to energy blackmail.  Domestic production of renewable energy reduces dependency on imported fossil fuels and gives a nation greater flexibility in foreign policy.  Many countries in the European Union are now ramping up renewable energy production in the face of threatened cut-off of fossil fuels from Russia. 

2.  The cost of renewable energy is decreasing.  Renewable energy is already cheaper than fossil fuel energy in some cases, and technological advances in generation, storage, and distribution will continue to drive down costs.  Each time a component of the global fossil fuel infrastructure ages to the point of needing replacement, a decision must be made to continue burning fossil fuel or switch to renewables.  From a purely economic perspective, the better decision may be to go with renewable energy.

3.  The cost of fossil fuels is increasing.  Currently, much of the environmental and social costs of fossil fuels are externalized, but as those costs begin to be covered by more stringent regulation and carbon taxes, the overall costs of fossil fuels will be pushed up.

4.  Public health.  Combustion of fossil fuels results in emissions of nitrogen compounds and hydrocarbons that participate in the formation of harmful ground-level ozone and particulates (Figure 1).  A long history of research and monitoring by environmental agencies supports the conclusion that ground-level ozone is detrimental to human and crop health.  The non-climate related economic benefits of reducing fossil fuel combustion (e.g. reduced sickness and death from air pollution) exceed the climate-related benefits in the early decades of greenhouse gas mitigation scenarios.

smog at sunset
Figure 1. Impacts of air pollution on human health and vegetation drive support for a global renewable energy revolution. Image Credit: jplenio from Pixabay

5.  Nitrogen deposition.  The nitrogen compounds associated with fossil fuel combustion eventually fall out of the atmosphere in precipitation or as dry deposition. This excess nitrogen is deposited to terrestrial, aquatic, and marine ecosystems and drives eutrophication and soil acidification.

6.  Job creation.  Building and maintaining an expansive renewable energy infrastructure will create on the order of seven times more jobs than will be lost from the fossil fuel and nuclear industries as they recede.  The issue of job creation will become increasingly important in the coming decades as computer-driven artificial intelligence displaces human beings.

The multiple rationales noted here for policies that support a renewable energy expansion will hopefully, in aggregate, move the needle away from further investments in the fossil fuel infrastructure.  Policies that stimulate renewable energy technology include subsidies on electric vehicles and residential solar power installation, whereas carbon taxes and regulation of drilling rights on public land can serve to limit fossil fuel development.

Of immediate concern is that a desire to reduce consumption of Russian fossil fuels will be used as a justification for increasing fossil fuel production in the U.S. and elsewhere.  Considering the long turnover time of fossil fuel infrastructure (e.g. 50 years for a coal burning power plant) and the ample opportunities for expanding renewable energy, great caution should be taken with investments that prolong the era of fossil fuels.

The Technosphere is Melting the Cryosphere

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Iceberg in Lilliehöökfjord, Svalbard.  Image credit: Hannes Grobe, CC BY-SA 4.0

David P. Turner / February 1, 2021

Earth system scientists think of planet Earth as composed of multiple interacting spheres.  The cryosphere is a term given to the totality of frozen water on Earth – including snow, ice, glaciers, polar ice caps, sea ice, and permafrost.

The cryosphere has a significant effect on the global climate because snow and ice largely reflect solar radiation, hence cooling the planet.

Unfortunately, the cryosphere is melting.  That loss of snow and ice is providing a significant positive (amplifying) feedback to anthropogenically induced global warming.

Over the course of Earth’s geological history, the cryosphere has existed as everything from nearly 100% coverage of the planetary surface around 700 Mya (million years ago) i.e. snowball Earth (Figure 1) to virtually disappearing during the Hothouse Earth period (about 50 Mya).

Figure 1. Snowball Earth.  The planet was nearly covered in snow and ice around 700 million years ago.  Image Credit: NASA.

The multiple glacial-interglacial cycles over the last several million years were initiated by changes in sun/earth geometry (the Milankovitch cycles), but strengthened by changes in snow/ice reflectance along with changes in greenhouse gas concentrations.

Figure 2.  Ice cover (black) shifted markedly between the glacial and interglacial periods over the last 3 million years.  Image credit:  Hannes Grobe CC Attribution 3.0

The culprit in the current melting of the cryosphere is something new to the Earth system – the technosphere.  This recently evolved sphere consists of the totality of the human enterprise on Earth, including its myriad physical objects and material flows.

By way of fossil fuel combustion, the technosphere is driving up the concentrations of greenhouse gases in the atmosphere and correspondingly, warming the global climate.  That new heat is causing reduced snow cover, receding glaciers, melting of ice caps, and loss of sea ice.  By various anthropogenically driven mechanisms, the cryosphere is also said to be “darkening” and hence melting quicker because more solar radiation is absorbed.

Projections by Earth system models of cryosphere condition over the next decades, centuries, and millennia suggest it will significantly wane if not disappear.

Besides the positive feedback to climate change by way of reflectance effects (and release of greenhouse gases from permafrost melting), the diminishment of the cryosphere will have profound impacts on the technosphere.

  1.  The circulation of water through the hydrosphere on land is regulated in many cases by accumulation of snow and ice on mountains.  That water is subsequently released throughout the year, thus providing stable stream flows for downstream irrigated agriculture and urban use. 
  2. The melting of glaciers and the polar ice caps will drive up sea level.  If all such ice is melted (over the course of hundreds to thousands of years), sea level is projected to rise 68 m.  The magnitude of sea level rise projected over the next 100 years for intermediate emissions scenarios is on the order of one meter.
  3. It remains controversial, but reduction of snow and ice cover may alter the behavior of the jet stream and could induce more extreme weather events in mid- to high latitudes of the northern hemisphere.

Efforts to reduce greenhouse gas emissions will certainly slow the erosion of the cryosphere and should be made.  The precautionary principle suggests we avoid passing tipping points associated with melting of the Greenland ice cap and the Antarctic ice cap.  However, the momentum of environmental change is strongly in that direction.

Once these ice caps are gone, there is a hysteresis effect such that the ice does not return with a simple reversion to the current climate (e.g. by an engineered drawdown of the CO2 concentration).

The planet is headed towards a warmer, largely ice free, condition.  The biosphere has been there before.  The technosphere has not.  Humanity will be challenged to develop adequate adaptive strategies.

Recommended Video: What is the Cryosphere │How it Affects Climate Change

Peak Carbon Dioxide Emissions and Peak Carbon Dioxide Concentration

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David P. Turner / December 2, 2020

Updated November 23, 2022 based on the 2022  Global Carbon Budget Report and the 2022 International Energy Agency World Energy Outlook Report.

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, which also releases CO2 (the sum is termed Fossil Fuel & Industry emissions).  Two independent emissions estimates (GCP and IEA) differ slightly. Deforestation is another significant anthropogenic source of CO2, but it is not considered in this blog post except to say that reducing deforestation will further reduce total CO2 emissions.

The suggestion that peak fossil fuel emissions occurred in 2019 held true in 2020 and 2021, but 2022 saw about a  1% increase over 2019.  However, there is significant uncertainty about these emissions estimates, especially of late considering how volatile the global energy market has become in 2022 because of the war in Ukraine.  It will thus be interesting to see the Global Carbon Project update of its 2022 emissions estimates (available in April 2023).  The input data set then will reflect observations over the complete year.

Despite the possible increase in emissions, the new IEA report calls 2022 a global turning point in the transition to a renewable energy future, an assertion based on the step-change in available financing (led by the Inflation Reduction Act in the U.S.).  The IEA also suggests that the 2020s will be the turning point decade in CO2 emissions, i.e. decadal emissions in the 2030s will be lower.

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

1.  The rate of increase in global emissions has been low in recent years (before the 2021 recovery from the Covid-19 pandemic), averaging less than 1% per year for 2010-2019.

2.  Global coal emissions in 2022 are about the same as in 2012.  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.

3.  Peak oil use may have occurred in 2019.  Global demand in 2020 fell 7.6% because of Covid-19, recovered by 4.4% in 2021, and increased an additional 2.2% in 2022.  Structural changes such as reduced commuting and business-related flying mean that some of the demand reductions associated with Covid-19 will be persistent.  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.

4.  Even a near-term peak in natural gas consumption is being discussed.  The GCP budget for 2022 shows a 0.2% decline in gas emissions.  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.

Surprisingly, it appears likely that a near-term decline in total fossil fuel use will be driven more by lack of demand than lack of supply.

Emissions from cement manufacturing fell slightly (1.6%) in 2022.  A recent study suggests that the CO2 uptake from slow weathering of aging cement around the world is providing a large offset (more than half) to current cement manufacturing emissions.  Innovative uses of wood and geopolymers can potentially replace cement in many construction applications.

The Biden administration has returned the U.S. (largest cumulative CO2 emissions on the planet) to the international fold with respect to climate change mitigation.  President Xi Jinping of China (largest CO2 emitter on the planet) has also displayed leadership on the climate change issue.  A revitalized collaboration between the U.S. and China on climate change mitigation could push the needle on global emissions reduction.

A critical missing piece in the global struggle to reduce CO2 emissions is the soaring use of coal in India (up 14.8% in 2021 and 5% in 2022).  Offers of climate finance from the more developed world could go a long way towards funding the needed renewable energy revolution there.

Currently about half of fossil fuel CO2 emissions remain in the atmosphere, with the remainder sequestered on the land (e.g. in vegetation and soil) and in the ocean.  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).

There is of course plenty that might go wrong.  The net effect on the land and ocean sequestration just referred to 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.

On the other hand, land sequestration is increasing now and could continue to do so in response to CO2 enhancement of photosynthesis and plant water use efficiency.  Policy driven increases in the land carbon sink (e.g. more reforestation and afforestation) are also possible.

Whatever specific years do turn out to be peak CO2 emissions and peak CO2 concentration, they will be remembered as historic hallmarks in humanity’s effort to address an existential threat of its own making.

Recommended:  Interactive CO2 Emissions and Concentration Projection Tool.

Earth Day 2020

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Earth Day 2020 and Global Solidarity

David P. Turner / April 19, 2020

Earth Day in 2020 is the 50th Anniversary for this annual gathering of our global tribe.  Historically, it has been an opportunity to note declines in environmental quality and to envision a sustainable relationship of humanity to the rest of the Earth system.

This year, in addition to the usual concerns about issues like climate change and ocean acidification, Earth Day is accompanied by concern about the specter of the COVID-19 pandemic.  A glance at the geographic distribution of this virus is the latest reminder that interactions with the biosphere, in this case the microbial component, can link all humans in powerful ways. 

Environmental issues that were on the front burner when Senator Gaylord Nelson initiated Earth Day in 1970 were mostly local − polluted rivers, polluted air, and degraded land cover.  These issues were addressed to a significant degree in the U.S. by passage of the Clean Water Act (1972), the Clean Air Act (1970), and the Endangered Species Act (1973).  These were national level successes inspired by environmental activism.

Awareness of global environmental change in 1970 was only dimly informed by geophysical observations such as the slow rise in the atmospheric CO2 concentration.  But by the 1980s, climate scientists began a drumbeat of testimony to governments and the media that the environmental pollution issue extended to the global scale and might eventually threaten all of humanity. 

The United Nations has functioned as a forum for international deliberations about global environmental change issues, and the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987 hinted at the possibilities for global solidarity with respect to the environment.

To help matters, economic globalization in the 1990s began uniting the world in new ways.  Huge flows in goods and services across borders fueled a truly global economy.  The level of communication required to support the global economy was based on the rapidly evolving Internet.  It provided the foundation for a global transportation/telecommunications infrastructure that now envelops the planet.

A political backlash to economic and cultural globalization has recently brought to power leaders like Donald Trump (U.S.) and Jair Bolsonaro (Brazil).  Their inclination is much more towards nationalism than towards global solidarity on environmental issues.

However, humanity is indeed united – in fear of climate change and coronavirus pandemics if nothing else.

Each year, 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.  This year, billions of us are locked down in one form or another to slow the spread of a virus that likely emerged from trafficking in wild animals.  In a mythopoetic sense, it is as if Earth was responding to the depredations imposed upon it by our species.

Philosopher Isabelle Stengers refers to the “intrusion” of Gaia (the Earth system) upon human history.  The message from Gaia is that she is no longer just a background for the infinite expansion of the human enterprise (the technosphere). 

Humanity can reply to Gaia with ad hoc measures like building sea walls for protection from sea level rise.  Or we can get organized and develop a framework for global environmental governance.

There are many impediments to becoming a global “we” that will work collectively on global environmental change issues.  Nevertheless, the incentives for doing so are arriving hard and fast.  The diminishment of the wild animal trade in China in response to COVID-19, and the unintended reduction of greenhouse gas emissions globally associated with efforts to slow the spread of COVID-19, signal that radical change is possible. 

Fitting testaments to an emerging global solidarity about environmental issues would be eradication of commercial exploitation of wild land animals everywhere in the world, and stronger national commitments to reduce greenhouse gas emissions relative to current obligations under the Paris Climate Agreement. 

Both initiatives of course face strong cultural and political headwinds.  But Earth Day, as one of the largest recurring secular celebrations in the world, is an opportunity to think anew.

Recommended audio/video:
One World (Not Three), The Police
https://www.youtube.com/watch?v=N0U-IaURsGM