Representatives from nearly 200 countries agreed at the COP28 climate summit on Wednesday to begin reducing global consumption of fossil fuels to avert the worst of climate change, a first of its kind deal signaling the eventual end of the oil age.
The deal struck in Dubai after two weeks of hard-fought negotiations was meant to send a powerful signal to investors and policymakers that the world is united in its desire to break with fossil fuels, something scientists say is the last best hope to stave off climate catastrophe.
COP28 President Sultan Al Jaber called the deal "historic" but added that its true success would be in its implementation.
"We are what we do, not what we say," he told the crowded plenary at the summit. "We must take the steps necessary to turn this agreement into tangible actions."
Several countries cheered the deal for accomplishing something elusive in decades of climate talks.
"It is the first time that the world unites around such a clear text on the need to transition away from fossil fuels," said Norway Minister of Foreign Affairs Espen Barth Eide. "It has been the elephant in the room. At last we address it head on."
More than 100 countries had lobbied hard for strong language in the COP28 agreement to "phase out" oil, gas and coal use, but came up against powerful opposition from the Saudi Arabia-led oil producer group OPEC, which argued that the world can slash emissions without shunning specific fuels.
That battle pushed the summit a full day into overtime on Wednesday.
Members of the Organization of the Petroleum Exporting Countries together control nearly 80% of the world's proven oil reserves along with about a third of global daily oil production, and their governments rely heavily on those revenues.
Small climate-vulnerable island states, meanwhile, were among the most vocal supporters of phasing out fossil fuels and had the backing of huge oil and gas producers such as the United States, Canada and Norway, along with the EU bloc and scores of other governments.
Low-lying islands fear extinction from rising sea levels and worsening storms, with the Marshall Islands denouncing an earlier draft as a "death warrant." That draft merely suggested nations "could" reduce the consumption and production of fossil fuels, among other options.
The bloc of small island states called the revised text "an improvement" but it reiterated concerns, saying that the deal was "incremental and not transformational."
However, Danish Minister for Climate and Energy Dan Jorgensen marveled at the circumstances of the deal: "We're standing here in an oil country, surrounded by oil countries, and we made the decision saying let's move away from oil and gas."
The deal specifically calls for "transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner ... so as to achieve net zero by 2050 in keeping with the science."
It also calls for a tripling of renewable energy capacity globally by 2030, speeding up efforts to reduce coal use, and accelerating technologies such as carbon capture and storage that can clean up hard-to-decarbonize industries.
Now that the deal is struck, countries are responsible for delivering on the agreements through national policies and investments.
In the United States, the world’s top producer of oil and gas and the largest historical emitter of greenhouse gases, for example, climate-conscious administrations have struggled to pass laws aligned with their climate vows through a politically divided Congress.
U.S. President Joe Biden scored a major victory on that front last year with passage of the Inflation Reduction Act, which contained hundreds of billions of dollars in subsidies for electric vehicles, wind, solar and other clean energy technologies.
Following the agreement, U.S. climate envoy John Kerry told the closing session of the summit that both the United States and China intended to update their long-term climate strategies, hailing the deal as one that "sends very strong messages to the world."
"Today, I would join with Xie Zhenhua and the Chinese delegation in announcing that the United States and China ... based on the many initiatives set out in the global stocktake decisions, we will again update our long term strategies and we invite other parties to join us in doing so," he said.
Mounting public support for renewables and electric vehicles from Brussels to Beijing in recent years, along with improving technology, sliding costs, and rising private investment have also driven rapid growth in their deployments.
Even so, oil, gas, and coal still account for about 80% of the world's energy, and projections vary widely about when global demand will finally hit its peak.
OPEC Secretary-General Haitham Al Ghais had said in a letter dated Dec. 6 to OPEC members and allies at COP28 that the world should target emissions rather than fossil fuels themselves, rallying them to oppose any deal targeting oil.
Oil producers have argued that fossil fuels can be cleansed of their climate impact by using technology that can capture and store carbon dioxide emissions. Carbon capture, however, is expensive and has yet to be proven at scale.
Rachel Cleetus, policy director at the Union of Concerned Scientists, said the deal "sends a strong signal that world leaders recognize that a sharp turn away from fossil fuels toward clean energy in this critical decade and beyond, aligned with the science, is essential to meet our climate goals."
But Jean Su, of the Center for Biological Diversity, while seeing progress, said there were still "cavernous loopholes" for fossil fuels.
The agreement tackles only fossil use in energy, not in industrial areas such as production of plastics and fertilizer.
She also voiced alarm at the recognition of the role of "transitional fuels," which she saw as a code word for producers of natural gas and other fossil fuels such as the United States on the grounds of energy security.
While not using the term "phase-out" on fossil fuels, it endorses work toward a phase-down of "unabated coal power" — meaning that coal with carbon capture technology to reduce emissions, panned by many environmentalists as unproven, could continue.
The biggest-ever COP meeting hosted more than 88,000 people, including a record number of lobbyists from the fossil fuel industry.
The 2015 Paris summit endorsed checking warming at 1.5 Celsius — a goal repeated in the latest draft, but which critics say is virtually impossible without serious efforts to curb oil, gas and coal.