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

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.