Greenhouse gas emissions from electricity generation fell 2% last year, the biggest annual drop since at least 1990, driven by reduced coal use in the European Union and the United States, according to a report released Monday by climate think tank Ember.

“But the report’s authors said a shift away from fossil fuels was not yet ‘the new normal’ and warned governments must ‘dramatically accelerate’ the transition to sustainable energy sources if the world is to avoid the worst impacts of global warming,” The Independent reports.

“The global decline of coal and power sector emissions is good news for the climate, but governments have to dramatically accelerate the electricity transition so that global coal generation collapses throughout the 2020s,” said lead author Dave Jones. “To switch from coal into gas is just swapping one fossil fuel for another.”

He added that “the cheapest and quickest way to end coal generation is through a rapid rollout of wind and solar.”

Reuters says coal-fired electricity generation must fall 11% per year to keep average global warming within 1.5°C. By contrast, the study determined that “coal-fired power generation fell by 3% globally, also the largest fall since 1990,” the news agency writes. “The drop in Europe was 24%, driven by a switch to renewables, while U.S. coal-fired generation was down 16% because of more competitive gas.” But China saw its emission increase and “became responsible for half of global coal-fired power generation.”

The report showed wind and solar increasing by 270 terawatt-hours, or 15%, an annual growth rate that will have to continue to meet the carbon reduction goals in the 2015 Paris Agreement.