With new evidence that global warming is affecting plant life, and a recent report to the U.N. from the Environmental Protection Agency indicating that human activity is causing the Earth to heat up, the United States is faced with even more evidence that fossil fuel consumption is affecting the global climate. The logic for staying out of the Kyoto treaty, which would require cuts in carbon-dioxide emissions, grows more flimsy every day.

The Kyoto accord was ratified Tuesday among fresh criticism for the United States, which is among the only industrialized nations in the world refusing to participate. This reluctance began under Bill Clinton and has continued under George W. Bush.

Even though the EPA, part of Bush’s own administration, is now shouting that carbon-dioxide emissions from humans are causing global warming, the president is still dismissing the evidence and insisting that voluntary compliance with new standards is the way to go.

It’s time to take the blinders off. Global warming is happening and scientists agree that the long-term effect will be harmful on the planet’s ecology, as well as to human interests. The United States must join the rest of the world in taking responsibility for its future and agreeing to new restrictions on emissions from fossil fuels.