To achieve net-zero greenhouse gas emissions in the United States by 2050, implementing green subsidies is essential, complemented by a potential carbon tax, both of which may face opposition under President Donald Trump.

Introducing a price or tax on carbon emissions stands out as the most effective strategy to curb carbon output. However, the U.S. government has continually struggled to enact cap-and-trade laws that would limit emissions and require companies surpassing these limits to buy allowances.

Subsidies are straightforward to deploy and could lower the cost of adopting low-emission technologies, including electric vehicles, thus alleviating the financial impact of carbon pricing.

Wei Peng at Princeton University analyzed the implications of subsidies and carbon taxes to find the most effective policy sequence for emissions reduction in the U.S.

The results indicate that subsidies could lead to a 32% reduction in energy system emissions by 2030; however, this impact may decrease over time as fossil fuels like natural gas remain economically viable.

Conversely, implementing a carbon tax in 2035 could result in the phase-out of most fossil fuels, reducing overall emissions by more than 80% by 2050.

“Subsidies will help cultivate green industries, but we will still require regulatory enforcement to meet decarbonization objectives,” states Penn. “The key question is how to navigate that transition.”

Following President Joe Biden’s 2050 net-zero aim, recent legislation has introduced tax incentives for investments in green infrastructure, ranging from electric vehicle charging stations to carbon sequestration technologies. In contrast, President Trump dismissed these subsidies as “the new green scam” and rescinded many of them.

This unpredictable policy landscape is “the worst-case scenario,” according to Peng. “This inconsistency will either slow down decarbonization or inflate costs.”

If subsidies are reinstated post-Trump’s presidency in 2029, along with introducing a carbon tax by 2045, researchers conclude that the carbon tax would need to be 67% higher than current rates to achieve net-zero emissions. This is primarily due to the necessity of employing costly technology to extract vast amounts of carbon dioxide from the atmosphere.

Yet, researchers suggest that “accelerated innovation” through unforeseen technological breakthroughs could lessen the need for stringent regulations.

The findings advocate strongly for a carbon pricing model, yet extending this analysis globally would yield richer insights into effective carrot-and-stick combinations, notes Gregory Nemet at the University of Wisconsin-Madison. Countries like China and those in the European Union have adopted extensive subsidies and carbon pricing initiatives, leading to advancements such as affordable solar panels, which empower other nations to cut emissions.

“Progress is ongoing in these regions, along with robust policy frameworks,” remarks Nemet. “This fosters accelerated innovation, and the U.S. stands to benefit significantly from this evolution.”