WASHINGTON (AP) — Democratic presidential candidate John Delaney is the latest 2020 contender to introduce a climate change plan, and he's proposing a fee on carbon emissions that he says aims to reduce them by 90% by midcentury.

That idea is part of the former Maryland congressman's $4 trillion plan, which is similar to one he offered while in Congress and drew some Republican support.

Climate change is one of the leading concerns of Democratic primary voters. But Delaney isn't among the candidates backing the Green New Deal, which has emerged as a sort of litmus test for the Democratic hopefuls.

The Green New Deal has been introduced in Congress and seeks to shift the U.S. away from fossil fuels such as oil and coal and replace them with renewable energy sources.

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