In his seventh State of the Union address on Tuesday, President Barack Obama made what may be his strongest case yet for combating global climate change.

“No challenge — no challenge — poses a greater threat to future generations than climate change,” Mr. Obama said. “2014 was the planet’s warmest year on record. Now, one year doesn’t make a trend, but this does — 14 of the 15 warmest years on record have all fallen in the first 15 years of this century.”

He cited a recent report by the National Oceanic and Atmospheric Administration that ranked 2014 the warmest year on record, and he called out climate change deniers.

I’ve heard some folks try to dodge the evidence by saying they’re not scientists; that we don’t have enough information to act. Well, I’m not a scientist, either. But you know what – I know a lot of really good scientists at NASA, and NOAA, and at our major universities. The best scientists in the world are all telling us that our activities are changing the climate, and if we do not act forcefully, we’ll continue to see rising oceans, longer, hotter heat waves, dangerous droughts and floods, and massive disruptions that can trigger greater migration, conflict, and hunger around the globe. The Pentagon says that climate change poses immediate risks to our national security. We should act like it.

The president’s speech follows on a recent study published in the Bulletin of the American Meteorological Society, which found that the 2013 extreme heat waves in Asia, Europe and Australia were caused by man-made climate change. Last week, a study published in Nature found that damage from climate change slows GDP growth in poor and wealthy countries.

Addressing climate change doubters was important, said Michael Gerrard, director of the Sabin Center for Climate Change Law at Columbia University. While in office, Mr. Obama has had no luck getting Congress to pass climate change legislation. A poll by Politifact recently found of the 278 Republicans currently in Congress, only eight believed that climate change was happening and that humans were the cause. Mr. Obama has instead relied on the regulatory power of the Environmental Protection Agency to make changes.

“I was pleased by how strong his statements were,” Gerrard said. “It was a stronger statement on using his powers to block negative moves by Congress.”

Using the EPA to make changes has been productive, although that avenue wasn’t the president’s preferred choice, said Robert Stavins, an environmental economist at Harvard University.

Last week the Obama administration announced new regulations that would reduce the amount of methane produced by natural gas drilling 45 percent by 2025.

This followed regulations announced by the EPA in June 2014 that would cut greenhouse gas emissions from U.S. power plants 30 percent by 2030.

Regulations that went into effect May 21, 2010 required car manufacturers to improve their fuel efficiency standards and reduce fuel consumption. (Gerrard called that “far and away” the president’s most effective policy for reducing climate change.)

Joni Ernst, the freshman senator who gave the GOP response to the State of the Union, has said she opposes the Clean Water Act and wants to abolish the EPA.

“Let’s shut down the EPA,” Ernst said in a primary debate in April 2014, according to a report by the Tampa Bay Times. “The state knows best how to protect resources.”

Congress has introduced bills that would limit the power of the EPA. Last night the president made it clear that those bills will not get past him without a veto, Gerrard said.

President Obama also touched on advances the country has made in energy production, including the growth of green jobs in the United States. Solar power added 31,000 jobs in 2014, according to the Solar Foundation. From Tuesday’s speech:

We believed we could reduce our dependence on foreign oil and protect our planet. And today, America is number one in oil and gas. America is number one in wind power. Every three weeks, we bring online as much solar power as we did in all of 2008. And thanks to lower gas prices and higher fuel standards, the typical family this year should save $750 at the pump.

Mr. Obama’s speech made a small mention of the Keystone XL pipeline, which would move oil from tar sands in Canada to refineries in the U.S. Congress has passed the bill to the Senate, and the president has vowed that he would veto the pipeline.

“President Obama will soon have a decision to make: will he sign the bill, or block good American jobs?” Ernst said on Tuesday.

Climate leaders will meet in Paris in December for the UN Climate Change conference, in hopes of reaching an international, legally-binding climate agreement.