Climate and environment updates: Colorado River at a tipping point due to drought

A major water supplier in the West is once again in the spotlight for its unpredictable future.

The Colorado River, the water source for 40 million people across the west, is in a worse state than previously believed, according to a recent study published in Earth's Future.

Drought and dry conditions, compounded by climate change, put the Colorado River in greater jeopardy, the study's authors said.

"It doesn’t take a lot of climate change to put the system into a very vulnerable future," said Dr. Patrick Reed, a civil and environmental engineer at Cornell University and co-author of the study.

Colorado's West Slope River Basins "are essential water sources for the Colorado River and play a vital role in supporting the state of Colorado's local economy and natural environment," according to the study. The West Slope River Basins contribute nearly 70% of the streamflow deliveries to Lake Powell, the nation's second-largest reservoir.

But drought has significantly depleted Lake Powell’s water supply, leading to the first-ever water shortage in the Upper Colorado River Basin in 2021 and more dependence on the West Slope Basin supply.

"The Colorado River is extremely stressed and overallocated," Reed said.

The Colorado River supplies water to seven states and Northern Mexico. Agreements about how the water is divided are up for renegotiation in 2026.

-ABC News' Charlotte Slovin

U.S. fuel economy reached a record high in 2023 at the same time that greenhouse emissions reached a record low, according to the U.S. Environmental Protection Agency's annual Automotive Trends Report released Monday.

The report also states that model year 2023 electric vehicles and plug-in hybrid vehicles have reduced carbon dioxide emissions by 11%.

"This report provides a critical data-driven affirmation that strong, technology-neutral standards can underpin environmental progress while saving drivers money at the pump," EPA Administrator Michael Regan said in a statement.

New vehicle CO2 emissions are now at a record low of 319 grams per mile, which reduces the impact on climate change. Battery and plug-in hybrid vehicles, combined with fuel cell vehicles, are expected to reach 14.8% of overall vehicle production in 2024, a trend that is expected to grow across the industry, according to the report.

Passenger cars and light trucks accounted for 17% of total U.S. greenhouse gas emissions in 2022, underscoring the need for further reductions across the industry, experts said.

-- ABC News Climate Unit's Dan Manzo

In a surprising turn of events, world leaders at the United Nations climate conference in Azerbaijan announced they have reached agreement on a new deal that calls for wealthy countries to contribute $300 billion annually to help developing nations deal with the effects of climate change.

After fears no deal would be reached as talks broke down, the announcement came around 3 a.m. local time and was met with a standing ovation and a wave of relief.

The deal in question was the "climate cash" agreement, under which developed nations will contribute an annual target of $300 billion to help climate-vulnerable, developing countries deal with the consequences of climate change.

President Joe Biden on Saturday praised the agreement, while touting his administration’s work on climate change, saying "nobody" can undo America’s "clean energy revolution," in an apparent swipe at President-elect Donald Trump.

"Today at COP29, thanks in part to the tireless efforts of a robust US delegation, the world reached agreement on another historic outcome," Biden said in a statement, going on to say the "ambitious" deal "will help mobilize the level of finance – from all sources – that developing countries need to accelerate the transition to clean, sustainable economies, while opening up new markets for American-made electric vehicles, batteries, and other products."

Biden, who is leaving office in less than two months, said states and cities will continue to tackle climate change -- notably not mentioning the federal government, while adding that no one can overturn progress on the issue, repeating something he said last week while visiting the Amazon.

In a statement, U.N. Secretary-General Antonio Guterres said he had "hoped for a more ambitious outcome" on both financing and climate change mitigation efforts from the conference.

"But this agreement provides a base on which to build," he said in the statement. "It must be honoured in full and on time. Commitments must quickly become cash. All countries must come together to ensure the top-end of this new goal is met."

Mukhtar Babayev, Azerbaijan's minister of ecology and natural resources who served as the COP29 president, said in a statement the $300 billion goal "represents the best possible deal we could reach."

The U.N. climate conference, known as COP29, was anticipated to be the "finance COP" -- the site of negotiations to determine how much fighting the climate crisis would cost and who would pay for it.

In 2015, under the Paris Agreement, participating countries agreed to set climate financing goals in 2024 that would account for the needs of developing countries.

-ABC News' Victoria Beaule, Fritz Farrow and Jack Moore

The U.N. climate conference in Azerbaijan was supposed to be the "finance COP." World leaders would determine how much fighting the climate crisis would cost and who would pay for it.

However, as COP29 winds down, many developing countries and nongovernmental organizations are dissatisfied with the current language in the proposed climate finance agreement.

In 2015, under the Paris Agreement, participating countries agreed to set a New Collective Quantified Goal, or NCQG, on climate finance in 2024 that would account for the needs of developing countries. Basically, how much money would each nation spend to support developing countries that are being disproportionately impacted by climate?

While several versions of the new NCQG have been proposed, a final agreement is still out of reach. The latest text calls for a $1.3 trillion climate finance investment annually until 2035 but only requires a $250 billion investment from developed countries.

"With a paltry climate finance offer of $250 billion annually, and a deadline to deliver as late as 2035, richer nations, including EU countries, and the United States are dangerously close to betraying the Paris Agreement," Dr. Rachel Cleetus, policy director for the Climate and Energy Program, Union of Concerned Scientists, said. "This is nowhere near the robust and desperately needed funding lower income nations deserve to combat climate change."

The latest NCQG language lays out a variety of funding sources that can play a part in reaching global climate finance goals, including multilateral development banks, or MDBs, that can distribute funds through grants and concessional loans for developing countries and adaptation projects.

However, the text does not make clear whether funds from MDBs are part of reaching the $250 billion goal or supplement that goal. It also includes provisions allowing for voluntary contributions from developing countries.

"The central demand coming into COP29 was for a strong, science-aligned climate finance commitment, which this appalling text utterly fails to provide," Cleetus said. "Wealthier nations seem content to shamefully renege on their responsibility and cave in to fossil fuel interests while unjustly foisting the costs of deadly climate extremes on countries that have contributed the least to the climate crisis."

World Resources Institute Global Climate, Economics and Finance Program Director Melanie Robinson agrees, releasing a statement Friday saying, "Developed countries should aim higher than the $250 billion they've put on the table."

"We should leave Baku with a goal that at least gets to $300 billion a year by 2035," Robinson said.

Tasneem Essop, executive director of Climate Action Network International, called the latest draft text "an insult to the people in the Global south."

"This latest draft text on the New Collective Quantified Goal is not just a joke -- it's an insult to the people in the Global South living on the front line of the climate crisis," Essop said. "In the meantime, millions of people's lives are at risk. We are angry, but we will keep fighting until the end."

-ABC News Climate Unit's Kelly Livingston and ABC News' Charlotte Slovin