Reducing US greenhouse emissions 50 per cent by 2030: is it likely?

Although many Americans accept scientist warnings that allowing global temperatures to rise more than 1.5 degrees Celsius above preindustrial levels (currently 1.1 degree Celsius) runs the risk of greater environmental calamities (including rising sea levels), just how likely is the US to uphold President Biden’s 2021 commitment to cut 50 per cent of greenhouse-gas emissions by 2030 compared to 2005 levels?

As it stands, the US only reduced greenhouse gas emissions by 2 per cent from 1990 to 2019, with renewable energy sources (wind, hydroelectric, solar, biomass, and geothermal energy) providing 21 per cent of all US electricity in 2020 with a record 834 billion kilowatt hours (kWh) ahead of nuclear (790 billion kWh) and coal (774 billion kWh) and only behind natural gas (1,617 billion kWh).  

So can the US greatly reduce greenhouse gas emissions, and play a major global leadership given it contributed 11 per cent of the world’s greenhouse gas emissions in 2019, second only to China with 27 per cent?

First, there will be an enormous fiscal cost for the US to reduce greenhouse gas emissions substantially, although a 2021 study published in Environmental Research Letters found that the cost of doing nothing could be immense if just 10 per cent of economic damages from climate change were to persist and reduce economic growth.

While the study found that resulting adverse economic impacts from global warming would be heavily borne by countries in Africa, South Asia, and Latin America given their already hot climates and a lack of resources available for adaptation efforts, a separate World Meteorological Organization report found that the US has faced half of the costs of more frequent extreme weather in recent decades with extreme Atlantic hurricanes since 1992 (prior to the 2021 Hurricane Ida)  costing nearly $1.2 trillion when adjusted for inflation.

The Chinese ministry estimates that its aim to achieve carbon neutrality before 2060 will cost China $US14.725 trillion (US dollars throughout article) over the next 30 years ($490 billion per year), despite China producing over 70 per cent of all solar photovoltaic panels, half of the world’s electric vehicles and a third of its wind power, and controlling many of the raw materials crucial for clean-tech supply chains, such as cobalt, rare earth minerals and polysilicon.

With the European Green Deal also committing $1.17 trillion in the next ten years to promote low-carbon economic growth, it remains to be seen how much the US will spend on addressing greenhouse gas emissions over time.

This is despite Congress eventually supporting President Biden’s Bipartisan Infrastructure Deal during November 2021, after considerable negotiation, to include a number of measures that will help reduce US greenhouse gas emissions.

The deal included $66 billion for sustainable transportation options that would also replace thousands of transit vehicles with clean, zero emission vehicles;

$7.5 billion to build the first-ever national network of Electric Vehicle chargers throughout the US to include highway corridors to facilitate long-distance travel;

and $65 billion to upgrade power infrastructure which will also facilitate the expansion of renewable energy.

Second, reducing greenhouse gas emissions may be complicated by those arguing for higher US population growth which could obstruct gross greenhouse gas reduction aims even if per capita US CO2 emissions continues having already declined from 23.2 metric tonnes in 1973 to 13.68 metric tons in 2020 with most of the decrease since 2000.

With an ageing population of 331.5 million people by 2020, after increasing just 7.4 per cent since  2010 at the “the lowest rate since the 1930s”, it was noted that one in five US residents will be of retirement age by 2023 and that the average age of newly arriving immigrants is 31 (over seven years younger than the median American).

Third, it is difficult to encourage a national response to reduce US greenhouse gas emissions given considerable energy policy preferences amongst the 50 states.

For example, between 2005 and 2017, Maryland had the largest decrease of CO2 emissions (38 per cent) and Idaho had the largest increase (at 17 per cent).

With New Hampshire, Washington, D.C., and Maine closely behind Maryland, the Northeast region as a whole reduced CO2 emissions by around 24 per cent while most Western states — including Washington and California — had a moderate rise or decrease during the same period.  

Other major state policy initiatives intended to reduce greenhouse gas emissions include California during 2018 committing to a fleet of five million zero-emission vehicles in use by 2030;

Hawaii in 2015 becoming he first state to pass legislation mandating that all the state’s electricity come from renewable sources before mid-century;

Texas having the highest wind power generation of all 50 states, although Iowa, Kansas, and South Dakota have the largest wind power supply in terms of percentage of total energy use (36.6 percent, 29.6 percent, and 30.3 percent); and

Vermont in 2005 establishing a law that requires a “50 percent reduction in emissions from the 1990 level of 8.1 million tons by 2028 and a 75 percent reduction by 2050 with the latter target increased during 2015 to 80-95 per cent below 1990 levels.  

However, commitments are difficult to achieve. The 2021 Vermont Greenhouse Gas Emissions Inventory and Forecast, while observing that the state had reduced carbon emissions by 13.1 per cent since 2005, also noted that carbon emissions were still slightly higher than 1990 levels.

Fourth, in the same way the Environmental Protection Agency was created in 1970 with the US economy continuing to grow while the absolute level of pollution began to shrink through new technologies like catalytic converters on autos and sewage treatment plants, the American population has to be convinced of the need to pay for cleaner, greener air, water, lands and buildings.

Hence, volatile economic times may complicate public support for measures to address greenhouse gas emissions, despite ongoing major differences between Democratic and Republican voters over the extent that human activity has contributed to climate change.  

For example, while an April-May 2020 Pew Research poll found that 65 per cent thought the federal government was doing too little to reduce the effects of climate change, and 79 per cent urged greater development of renewable energy, an October 2021 Yahoo News/YouGov poll found that just 50 per cent viewed climate change as an "existential threat" with only 48 per cent favouring cutting greenhouse gas emissions in half by 2030 with 27 per cent opposed to the idea.

Perhaps changing US public attitudes reflects rising international energy prices for gas, coal and oil in 2021 as economic recovery from the covid-19 disaster around the world is thwarted by constrained supply.

With US natural gas prices alone increasing over the past year (as of October 2021), thus leading to a greater use of coal to generate electricity, the US Energy Information Administration’s Winter 2021 forecast predicted that homes heated with natural gas, fuel oil, and propane will see average price increases of 30-54 per cent respectively, although a modest 6 per cent increase for homes using electricity. 

However, while critics of renewables argue that wind and solar are at the mercy of Mother Nature, others note that the price of electricity is determined by whichever fossil fuel-based power plant has the highest cost and what is happening to the price of natural gas, oil or coal, and that energy prices would be even higher without renewables.

Prior to the covid-19 disaster of 2020, the price of renewables had fallen considerably against other energy sources since 2010.    

Between 2010 and 2019, the price of one megawatt hour (MWh) for solar electricity fell from $378 to $68/MWh with similar price reductions for offshore and onshore wind, while the global price of power from new coal fell from $111 to just $109.

Another source, examining data from 2010 to 2018, indicates that renewables had become the lowest cost option with subsidised wind prices being in the range of $28–$54 per megawatt hour (MWh) and unsubsidized utility-scale solar $32–$42/MWh, thus comparing favourably with nuclear at $118–$192/MWh, coal at $66–$152/MWh and a gas combined cycle at $44–$68/MWh.

Factoring in subsidies, wind prices plunge to $11–$45/MWh and utility-scale solar prices stay relatively stable at $31–$40/MWh.

When considering new generation capacity, looking at the marginal costs to run existing coal or nuclear—$26–$41/MWh and $27–$31/MWh respectively, it is argued that building new renewable energy remains competitive with running existing generation.

Although the US Energy Information Administration expected electricity generated by coal-fired plants to rise by 22 per cent in 2021, the first rise since 2014 after no new coal plants had opened in the US since 2013, it predicted a 5 per cent drop in coal-fired power generation in 2022 to below 2019 levels as natural gas prices eased.

According to the National Renewable Energy Laboratory’s 2019 Annual Technology Baseline, wind technologies will decline at least another 64 per cent by 2050 in its optimistic scenario and at least 44 per cent in its mid-level scenario with solar having similar scenarios of 74 and 47 per cent.

However, the lower cost of greater renewable energy sources must also give adequate attention to the cost of disposing used parts such as used solar panels.

At present, it has been estimated that it costs around $20-30 to recycle one solar panel whereas sending that same panel to a landfill would cost a mere $1-2 with the latter option complicated by panels having hazardous waste because they contain small amounts of heavy metals (including cadmium and lead).

While solar panel recycling legislation may result, hopefully sooner rather than later, there will be a considerable cost from dealing with end-of-life renewables infrastructure that encompasses uninstallation and transportation, with experts also expecting that more than 720,000 tons worth of “gargantuan wind turbine blades will end up in U.S. landfills over the next 20 years while only five percent of electric-vehicle batteries are currently recycled”.

Nevertheless, based on the above evidence and assuming that policies will be implemented to adequately address the disposal of discarded renewable energy materials, I do believe that the US will reduce greenhouse emissions in line with growing world awareness that such measures are needed to temper the adverse impacts of global warming, although it may prove difficult to achieve the Biden Administration’s target of 50 per cent of greenhouse-gas emissions by 2030 compared to 2005 levels.