The extreme weather. The melting glaciers. The weirdly warm oceans. They’re all the product of global warming, which is being driven by the release of the three most important heat-trapping gases: carbon dioxide, methane and nitrous oxide.

And according to a new study from the National Oceanic and Atmospheric Administration, emissions of those three greenhouse gases continued to surge last year to historic highs.

Global average carbon dioxide concentrations jumped last year, “extending the highest sustained rate of CO2 increases” in NOAA’s 65 years of record-keeping. Methane and nitrous oxide levels also rose sharply last year. All this despite a wave of global policy measures and economic incentives designed to wean the world off fossil fuels.

These weren’t just one-off anomalies. In each case, the rising emissions continued a long-term trend. By analyzing more than 15,000 air samples from around the world, NOAA found that the upticks in emissions last year “were in line with the steep increases observed during the past decade.”

The result has been a series of profound changes to the planet in a remarkably short amount of time. “The amount of CO2 in the atmosphere today is comparable to where it was around 4.3 million years ago during the mid-Pliocene epoch,” the NOAA report found. That was when the “sea level was about 75 feet higher than today” and “large forests occupied areas of the Arctic that are now tundra.”

Carbon dioxide

Last year, humans spewed some 36.6 billion tons of CO2 into the atmosphere, the most ever. That number may well be higher this year.

The concentration of carbon dioxide in the atmosphere is now more than 50 percent higher than it was before the industrial revolution.

It’s no secret where all this carbon dioxide is coming from. The burning of oil, coal and gas is the main source of CO2 emissions, and the use and production of fossil fuels continues to rise around the world, with the United States producing more oil and gas than ever before.

And even as the build out of renewable energy is speeding up, the appetite for fossil fuels remains strong, in part because overall energy demand is soaring.

Fossil fuels aren’t the only source of carbon dioxide. The extraordinary forest fires that have charred Canada, Europe and Chile over the past year are also adding CO2 into the atmosphere. Yet even there, the vicious cycle of human-caused climate change is easy to see: Many of those fires were made worse because of the warming that has already occurred.

Methane

For a while, it looked like methane emissions were slowing down. After a rapid rise in atmospheric methane concentration during the 1980s, levels stabilized in the late 1990s and early 2000s. Then in 2007, they started rising again, and fast.

Researchers acknowledge they don’t fully understand what accounted for the relative stability of methane output and then its renewed growth. But what is clear is that methane emissions are booming today.

Last year saw the fifth-highest ever jump in methane concentration since record keeping began, and methane levels are now more than 160 percent higher than they were before the industrial revolution, according to NOAA. Methane is a particularly potent greenhouse gas; while it breaks down faster than carbon dioxide, it is more powerful at trapping heat in the atmosphere.

The vast majority of the increased methane emissions can be traced back to humanity’s insatiable appetite. Agriculture is the biggest source of methane emissions, according to the International Energy Agency, followed closely by the burning of fossil fuels.

Nitrous oxide

While carbon dioxide and methane are the two gases most commonly associated with climate change, nitrous oxide is another potent heat-trapping gas, and is also on the rise.

N2O emissions are also linked to food. In this case, they are largely the result of nitrogen fertilizer and manure used in agriculture. Another source is aviation. Nitrous oxide levels in the atmosphere are now 25 percent higher than before the industrial revolution.

Where all that gas goes

In just a few hundred years, humans have radically altered the composition of Earth’s atmosphere, quite literally setting the planet back millions of years. Slowing down global warming, and potentially even reversing it, will require an equally herculean effort to stop emitting the three gases most responsible for climate change.

Reducing carbon dioxide emissions will require radical overhauls to our energy and transportation systems. Drawing down methane and nitrous oxide emissions will mean fundamentally overhauling how food is produced.

The changes won’t be easy. But until we figure out how to limit the release of carbon dioxide, methane and nitrous oxide, our world will keep warming.

A landmark ruling in Europe could mean more climate litigation

Europe’s top human rights court said on Tuesday that the Swiss government had violated its citizens’ human rights by not doing enough to stop climate change, a landmark ruling that experts said could bolster activists hoping to use human rights law to hold governments to account.

“I expect we’re going to see a rash of lawsuits in other European countries, because most of them have done the same thing,” said Michael Gerrard, director of the Sabin Center for Climate Change Law at Columbia University. “They have failed to meet their climate goals, and failed to set climate targets that are adequate.”

It was the latest sign that the global wave of lawsuits seeking to hold companies and governments responsible for damage caused by climate change is gaining momentum.

In the United States, states, cities and counties are suing fossil fuel companies over the damages caused by climate change, and young people are suing states and the federal government over what they say was a failure to protect them from the effects of global warming.

Legal experts are watching closely to see whether the Supreme Court will take up a lawsuit that Hawaii has brought against big oil companies. Should the country’s top court intervene, it could be helpful for fossil fuel corporations, which believe they have a better chance at winning in federal court than in many state courts.

The European ruling is unlikely to affect how U.S. courts rule, according to Gerrard. “The U.S. courts traditionally pay little regard to international tribunals,” he said.

But Gerrard added that many similar concepts are involved in the European case and those making their way through the court system in the United States.

“The idea that climate change impairs fundamental rights resonates throughout the cases,” he said. “The language is different, but the underlying concepts, and the idea that the governments have a duty to act, are the same.”

Similar legal efforts are unfolding around the world. India’s Supreme Court handed down a ruling last month concluding that people’s right to be shielded from the effects of climate change falls under the articles of the country’s constitution that protect the right to equality and to life. And the Inter-American Court is also preparing to issue an advisory opinion on whether countries are legally required to protect citizens from climate change. — David Gelles and Manuela Andreoni