Just a few years ago oil companies said they felt unwelcome at United Nations climate talks. Not this year.

This year's climate conference is taking place in the United Arab Emirates, a major oil and gas producing country that's looking to increase its oil production. And the oil industry has a big platform at the talks.

The oil cartel OPEC has its own pavilion at this meeting, known as COP28, and giant oil companies are playing a prominent role, to the dismay of climate activists.

So what are oil producers saying in their pledges and statements about climate change? And what does it actually mean?

Most oil companies acknowledge that climate change is real. Yet they also argue strongly for the world's continued use of massive quantities of fossil fuels, which power both the global economy and their profits.

But climate scientists say it's crucial to cut fossil fuel use sharply to avoid some of the worst effects of global warming.

"It's important to consider what these companies are committing to, what policies they support," says Paasha Mahdavi, associate professor of political science at the University of California, Santa Barbara, noting that oil companies' language can make it into policy. "Language is very revealing."

But this language isn't always straightforward. Here are five key, but sometimes confusing, phrases about climate change commonly used by oil companies – and why they matter.

Low carbon and lower carbon

"Carbon," short for carbon dioxide, is at the heart of climate talks. Most carbon dioxide emissions come from burning oil, gas and coal – and they heat the planet.

Many oil companies talk about their support for "low carbon energy" and "lower carbon energy."

"We believe the future of energy is lower carbon," Chevron, an NPR sponsor, frequently emphasizes in ads and speeches.

Mahdavi says the focus should be on the words "low" or "lower". It doesn't mean no carbon emissions, he says.

He says when companies push for more "lower carbon energy," it typically means continuing to produce and use oil and gas – but with somewhat cleaner extraction and processing methods. "You're just doing it with fewer emissions, but the end product still can have a lot of carbon in it," Mahdavi says.

For Chevron and other companies investing in "lower carbon" initiatives, the phrase sometimes refers to cleaner alternatives to fossil fuels, like getting energy from heat inside the earth. More often, it describes cleaning up the production and use of fossil fuels. That includes reducing emissions of methane, a potent greenhouse gas, during fossil fuel extraction.

This past weekend, a group of oil companies (though not Chevron) announced a pledge to reduce their methane emissions – but scientists say that is only accounting for a small fraction of overall emissions from oil and gas.

Or another key technology in the "low carbon" energy bucket is called "carbon capture and storage." That refers to capturing carbon pollution from fossil fuel production and industry, injecting it underground, and storing it before it reaches the atmosphere.

But experts say carbon capture technology isn't fully proven: projects often haven't reduced as much emissions as they said they would and are often over budget. Climate scientists say that carbon capture can't reduce the bulk of emissions, and really reducing carbon requires using less fossil fuels.

Unabated fossil fuels

"Unabated fossil fuels." It's a wonky phrase that will come up a lot at this year's climate talks. That's because much of the conference involves a big push from countries to reduce or get rid of "unabated fossil fuels". This past weekend the U.S. joined other nations in a pledge to phase out "unabated" coal.

That might sound a lot like eliminating fossil fuels.

But, again, notice the word "unabated." It describes emissions from coal, oil or gas that go straight into the atmosphere and heat up the planet.

Oil companies instead focus on "abating" emissions from producing and using fossil fuels, which means stopping at least some of the emissions from entering the atmosphere.

The industry argues carbon capture and storage – that "low-carbon" technology with a poor track record of success – could accomplish this. Experts have major concerns.

ExxonMobil - which is also a sponsor of NPR - has promos on NPR programming that tout carbon capture. (NPR has strict separations between the news division and its sponsorship unit. When asked about these sponsorships, an NPR spokesperson noted that "NPR has no list of sources from which funding will be refused. However, conflicts of interest or similar concerns are considered.")

What the world decides around these words – abated or unabated - has huge implications for oil and gas producers.

If the world's leaders decide to only phase out "unabated" fossil fuels, that would theoretically allow for oil production to continue indefinitely, if combined with new pollution trapping and storage technology.

Net Zero

Many oil companies have spotlighted something called a "net zero" ambition. The whole world, in fact, set a "net zero" target at the climate talks in Paris eight years ago.

What "net zero emissions" means is that the pollution humans produce that is heating the planet would get canceled out by removing the same amount of emissions from the atmosphere.

That can be done by planting trees or building giant machines to pull carbon from the sky. But those can only compensate for a small fraction of the carbon dioxide people emit today.

Reaching true "net zero" requires cutting global emissions enormously, scientists say.

But "net zero" can be a slippery phrase. Some oil companies setting "net zero" targets are referring only to the emissions in their operations – not to the emissions from the oil they sell.

So they might use solar panels and wind turbines to power oil drilling rigs and consider their "net zero" goals met – even as the oil they produce releases vast quantities of carbon pollution when it's burned as gasoline or jet fuel.

Reducing emissions from oil production is an important part of the climate fight, and more companies need to focus on this, climate experts say. But it's not enough to meet the world's net zero goals – which are the objective of the U.N.'s climate talks happening now.

That will require using far less oil in the first place, according to these experts.

Reliable and affordable energy

Fossil fuel companies often mention "reliable and affordable energy" in ads and speeches.

They're not normally referring to cleaner energies like wind and solar, however. In fact, it's usually shorthand for oil and gas, says Bob McNally, President of Rapidan Energy Group, an energy consultancy with clients that include big oil companies. "The reason that we're 80 percent dependent on fossil fuels is because it is reliable, it's affordable, and it's secure," he says.

"Reliable," "affordable," and "secure" often work as digs at renewable energy.

Reliable: A common talking point among fossil fuel supporters is that the sun doesn't always shine, and the wind doesn't always blow. Climate groups say this is being addressed with huge power storage batteries and a better electric grid.

Affordable: That's often an oil industry reference to the high costs of transitioning to a new technology. Climate groups argue the costs of renewables have been falling sharply, and failing to stop climate change will also carry tremendous costs.

And secure: The industry points to the scramble for fossil fuels after Russia invaded Ukraine as proof of how much the world still depends on these energy sources. And they say renewable energy relies on materials and manufacturing from abroad, while the US has lots of oil and gas here. Supporters of renewable energy argue they're actually more "secure" than oil, which is constantly fluctuating in price.

The oil industry also says that fossil fuels are a reliable and cheap way to help developing economies expand electricity access, given that 745 million around the world are without it, according to the International Energy Agency.

Reached for comment about this story, an ExxonMobil spokesperson called NPR's analysis "simplistic," arguing more oil and gas production is necessary to maintain and raise global living standards. The company also referred NPR to a recent speech from its CEO, Darren Woods, where he said, in part: "The societal benefits of oil and gas are unmatched in human history... No country has ever joined the developed world without access to oil and gas."

Similarly, in an online panel before the climate talks, the president of COP28, Sultan al-Jaber – who is also the CEO of the U.A.E.'s state-run oil company – said: "Show me a roadmap for a phase-out of fossil fuels that will allow for sustainable socio-economic development, unless you want to take the world back into caves."

In fact, such roadmaps exist, and many experts say renewable energy can be used to fuel development.

Paris-aligned

Eight years ago, the world set a shared target of holding global warming below 2 degrees Celsius, and ideally below 1.5 degrees Celsius. That's called the Paris Agreement. But the world did not agree on how to get there.

Working out the how is what these climate talks are all about. And as they join the conversations, many oil producers will say they support the Paris Agreement, and talk about "Paris-aligned scenarios."

Chevron, for instance, responded to NPR's request for comment on this story in part by saying: "There are many potential pathways to achieving the goals of the Paris Agreement, the vast majority of which include the continued use of oil and gas for the foreseeable future."

But how much oil? Scientists have found that every pathway for meeting Paris targets includes reducing the use of oil and gas.

This is what's at stake at the U.N.'s climate talks. The world is trying to figure out how exactly to meet the Paris goals – which experts say is difficult, but doable, if the world cuts the use of fossil fuels.

And the oil industry is at the talks to openly argue that the world will not and should not switch away from oil and gas.