Landmark climate legislation passed in the United States in 2022 could nearly halve the U.S. economy’s overall emissions compared to 2005 levels by 2035, according to a new analysis. But on its own, it still won’t be sufficient to meet the country’s pledges under the Paris Agreement.
The Inflation Reduction Act (IRA) is possibly the most significant piece of U.S. climate legislation yet. Its provisions include tax credits for clean energy, energy storage, and carbon capture; measures to promote energy efficiency, reduce methane emissions, develop domestic supply chains, and ensure environmental justice; and many others.
In fact, the IRA is so big and complex that its effects on the energy system and economy can’t simply be totted up but instead must be analyzed using powerful computer models. In the new study, the most extensive effort yet to get a handle on the legislation’s impact, researchers used nine different models to estimate the likely impacts of the IRA’s most important provisions.
The models varied in their scope (six encompassed the entire U.S. energy system while the remaining three only included the electricity sector) and level of detail. Some of the models were used to inform discussion prior to the IRA’s passage, and others were added new for this analysis. The researchers analyzed the similarities and differences between the predictions of the different models, and compared them to a hypothetical scenario in which the IRA had not been passed.
By 2035, overall emissions of the U.S. economy are likely to be 43 to 48% lower than they were in 2005, the researchers report in the journal Science. Without the IRA, emissions would be 27-35% below 2005 levels, they calculated. This is one of several findings that indicate the IRA is likely to accelerate existing trends in the economy. In short, the green transition is already happening, but the IRA speeds it along. [Continue reading…]