Ensuring that natural gas does not fill the energy void left by coal will be an even trickier proposition. While the leading Democratic candidates agree that fighting climate change should be a priority for the country, none has called for limits on the expansion of natural gas.
Natural gas has been referred to as a “bridge fuel.” The idea is that it should be used to reduce dependence on dirtier energy like coal and heating oil on an interim basis while the costs of renewables like wind and solar fall.
Mr. Pope said the campaign was prepared for a “major communication challenge” to persuade people that the bridge has been crossed.
Karen Harbert, president of the American Gas Association, an industry group, called Mr. Bloomberg’s plan a “beyond energy” campaign. She noted that, overall, United States emissions have come down drastically over the past decade thanks in part to natural gas, and said that, without it, renewable energy would stagnate.
Natural gas is no longer a transitional fuel, Ms. Harbert said, but “foundational in our energy landscape.”
According to the United States Energy Information Administration, a government agency that tracks energy data, natural gas currently meets 28 percent of United States energy demand, while about 11 percent comes from renewable sources.
Kevin Book, managing director at ClearView Energy Partners, a research firm, called Mr. Bloomberg’s campaign “a tall order.” He estimated that replacing the country’s remaining coal capacity with wind and solar power could cost as much as $800 billion in hardware and require an additional $150 billion to increase energy storage capacity.
“It’s not going to be easy to do what he’s talking about doing,” Mr. Book said.
Mr. Bloomberg has already donated more than $150 million to the Sierra Club and other environmental organizations as part of his previous environmental campaign, known as Beyond Coal. He announced in March that he would not run for president in 2020.
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