But one of the biggest reasons for Phoenix's high pollution levels is actually cattle ranches found south of the city, in Pinal County and vicinity.. "Those cattle ranches are contributing a lot of fine particle pollution to the small communities near them that are part of the Phoenix metro area, but also to the tribe adjacent to it, " says Nolen.

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And a lot of those gardeners use pollution-spewing leaf blowers all year long.

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Putting the bakery goods and coffee grounds through a biorefining process would also have the added benefit of keeping a lot of waste out of the waste stream while also reducing pollution from incineration.

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They carry a lot of unwanted baggage (trash, pollution, sewage) and too much too fast can devastate a community, like Edmonston, with terrible flooding.

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Meanwhile, Japan's recall of Meiji baby formula because of pollution by a radioactive substance has also raised a lot of concern.

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And that's at the same time that we're going to be hitting them with a lot of other challenges besides climate change - pollution and land use change, deforestation and fragmenting of the landscape.

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But when it comes to reducing pollution-causing emissions, electric vehicles have a lot of competition from cars powered by natural gas.

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Water is a more serious problem, both because a lot of it is needed to frack wells and because local groundwater is seen to be at risk of pollution.

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