Does Brazilian Deforestation Drive Drought In The United States?

28 July 2014 | Severe drought conditions in the US state of California have led state officials to impose criminal penalties for water wasters. The drought could also help make the case that California should allow projects aimed at curbing tropical deforestation into the state’s carbon trading system.

California’s State Water Resources Control Board approved an emergency regulation to force water agencies, their customers and state residents to increase water conservation in urban settings by reducing outdoor water uses such as washing down driveways and watering landscapes or face possible fines of up to $500 a day. What brought on this surge in water regulation? The fact that California residents are using more water than last year with urban water use in May up 1% over the monthly average for the previous three years despite two drought emergency declarations by Governor Jerry Brown and his January plea for residents to voluntarily reduce their water use by 20%.

What may seem like a local problem could have its roots in the tropical deforestation that has occurred in Brazil and other countries. Researchers found that total deforestation of the Amazon rainforest could reduce rainfall in the Pacific Northwest by 20% and cause a 50% reduction in the Sierra Nevada snowpack, a crucial source of water for California, according to a major scientific study published in the Journal of Climate last year.

Although it is difficult to quantify whether specific weather patterns such as the current drought are directly tied to deforestation, data trends indicate that deforestation has a direct impact on rainfall in California, according to Rajinder Sahota, Chief of the Climate Change Program Evaluation Branch of the California Air Resources Board (ARB), who spoke at an ARB board hearing on Thursday. But it remains difficult to convince residents of any possible connection, especially when they dealt with mudslides and floods in the state last year, she said.

“People tend to latch on to the most recent events as an indication of what’s going on, Sahota said.

The role of tropical deforestation and the possible connection to California’s drought arose in the context of an update that ARB staff was providing regarding its planned consideration of sector-based offsets, specifically from projects that reduce emissions from deforestation and forest degradation (REDD). ARB’s legal counsel Jason Gray discussed the multiple co-benefits of REDD projects, including protection against decreased precipitation from forest loss, which could be of interest given the current drought situation.

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