The Regional Greenhouse Gas Initiative, the country’s first regional system for capping carbon emissions and creating a market in carbon allowances, proposed a fundamental change on Thursday to increase electrical utilities’ incentive to cut emissions from fossil-fuel plants by raising the cost of compliance.

The regional group proposed a 45 percent reduction next year in the total carbon dioxide emissions allowed. The cut is not as draconian as that number suggests, however, because the new total of 91 million tons reflects the current emissions level after five years of a slumping economy and increases in renewable energy and energy-efficiency measures.

The reduction from 165 million tons is expected to raise the price of compliance, and further reductions of 2.5 percent annually were likely to increase the value of the allowances that utilities must submit for every ton of carbon dioxide, or its equivalent, that they emit.

If the proposal goes into effect, the analysis done by the group, which is a collaboration of nine states to cut carbon emissions, indicates that by 2020, allowances that are now trading at $1.93 could trade as high as $10. That would be roughly at the level where allowances for California’s new economywide cap-and-trade system were auctioned last fall.