Climate change

The US government has proposed a plan for the drought stricken Colorado River that could cut up to 40% of current supplies to Arizona, California and Nevada, as the waterway’s reservoirs continue to plunge to critically low levels.

A top Arizona water official shared details of the Trump administration’s plan at a state meeting on Wednesday.

Under the 10-year plan, which will be finalized in June, the annual amount of water delivered to Arizona, California and Nevada could be slashed by up to 3m acre-feet, according to Tom Buschatzke, director of the Arizona department of water resources. The reductions would be evaluated every two years.

Three million acre-feet of water is enough to supply 6 million to 9 million households for one year, more than the number of homes in Arizona and Nevada.

Buschatzke said the federal plan would be either implemented under existing Colorado River law or through agreements among the states. He said federal officials had indicated that water cuts across the three lower-basin states would be based on the “priority of the law of the river”. That law, the 1922 Colorado River Compact, gives California the highest priority for water use.

Buschatzke described the proposed federal cuts as “sobering”.

“That’s us, that’s Arizona, and potentially CAP going to zero,” said Buschatzke, referring to water flows on the Central Arizona Project, a canal that transports Colorado River water to central and southern Arizona.

The Colorado river supplies water to some 40 million people in the American west. The plan comes months after the seven states that depend on the river’s dwindling supply missed a February federal deadline to agree upon how water cuts would be divided. The river has lost about 27.8m acre-feet of groundwater in the last 20 years, largely owing to overuse. A record snow drought this year further exacerbated the issue.

The river’s upper basin states, Colorado, Utah, Wyoming and New Mexico, have been resistant to water reductions. The states maintain that those downstream, California, Arizona and Nevada bear responsibility for the water’s shortages and thus should carry the burden of cuts.

Independent, UK -   Global warming is causing rivers to slowly lose oxygen, threatening fish and other lives in the waterways, a new study shows.

Researchers in China used satellites and artificial intelligence to track and analyze oxygen levels in more than 21,000 rivers across the globe since 1985. They found oxygen levels have dropped an average of 2.1% since 1985, according to a study published Friday in Science Advances. That doesn't seem like much but it adds up and if it continues or accelerates, rivers in the Eastern United States, India and across the tropics could lose enough oxygen by the end of the century to suffocate some fish and create dead zones, the study said.

Basic chemistry and physics dictate that warmer water holds less oxygen, scientists said. Warmer water, which happens with human-caused climate change, releases more oxygen into the atmosphere.

The Guardian -   The climate crisis should be declared a global public health emergency by the World Health Organization, or millions more people will die unnecessarily, leading international experts have said. The independent pan-European commission on climate and health, which was convened by the WHO, concluded the climate crisis was such a worldwide threat to health that the WHO should declare it “a public health emergency of international concern” (Pheic).

The international spread of vector-borne disease, such as dengue and chikungunya, as well as the health impacts of extreme weather events, global heating, food insecurity and air pollution make a Pheic necessary, said the commission’s report, which will be presented to European ministers on Sunday before the WHO’s world health assembly starts on Monday.

Pheics are the highest level of health alert. Previous declarations include infectious diseases such as Covid and Mpox. While declaring one would not on its own reverse climate change, it would trigger the kind of coordinated international response that the scale of the health crisis demands but has not yet materialised.

The 11-strong independent commission, which includes former health and climate ministers, said: “Far from being a fading priority or fake news, climate change poses an immediate and long-term threat to health, economic, food, water, environmental, personal, community and national security.”