The climate threat|Global challenges

Alaska's rivers change color: "Sour as lemon juice"

Rivers in Alaska have changed color to orange. In a study, climate change is singled out as the likely cause, reports the Washington Post.

- More than 75 water bodies have undergone a chemical change, says Brett Poulin, researcher in ecotoxicology and one of the study's authors.

The phenomenon may have occurred when permafrost melted due to rising temperatures. In connection with that, sulphide minerals, including iron, may have been released into the water. When they react with oxygen, rust occurs, which can explain the color change.

Poulin says some water tested is "acidic like lemon juice."

There are two major concerns, that the metals will be toxic to organisms and that local communities that depend on the water will suffer.

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Climate change is making Africa's cholera crisis even worse

Parts of Africa have been hit by extreme weather in recent years, and in its wake the cholera crisis is worsening. That's what AP writes.

Malawi, Zambia, Zimbabwe, Kenya, Ethiopia and Somalia are some of the affected countries.

- The outbreaks are getting much bigger because the extreme climate events are becoming much more common, says Tulio de Oliveira, a researcher in South Africa who has studied the spread of disease.

The situation is further aggravated by a global shortage of cholera vaccine.