World Bank on Coursera: "Turn Down the Heat"

Click here to read the first post in my series on expanding my education through MOOCs.

The latest in my MOOC-athon was a course developed by the World Bank's climate change group: "Turn Down the Heat: Why a 4 Degree Celsius Warmer World Must Be Avoided."

Despite its unwieldy title, I was impressed by this course. It filled in the technical gaps in my climate change-related knowledge -- for example, why exactly are sea levels rising? how can climate change cause both drought and floods in the same region? -- and provided statistics that I can cite in future assignments.

For the final project, students were instructed to "create a digital resource that conveys an action or program that a community, country or region can implement to respond to climate change." Since I just returned from a trip to San Francisco, I decided to dig a little deeper into the causes of California's drought, and highlight a few promising (and not-so-promising) policy measures. Per the project's instructions, I'll structure my analysis as an educational tool targeting a general audience:

Causes of California's Drought

California is now three years into its worst drought in history. The drought has triggered wildfires, air pollution, and billions in agricultural losses, and Governor Jerry Brown has declared the state a "natural disaster area." But what caused the drought?

Since December 2012, a zone of high atmospheric pressure off the West Coast -- four miles high and 2,000 miles long -- has prevented rain and winter storms from reaching California. While high pressure zones commonly appear during the winter months, the strength and persistence  of this particular zone (dubbed the "Ridiculously Resilient Ridge") is unprecedented in modern history.

Although diverted rainfall has contributed to the drought, snow is the more significant factor, as snowpack provides 75 to 80 percent of the state's usable water. During the winter and early spring, snow sticks to California's Sierra Nevada mountain range, and then slowly melts into reservoirs and groundwater aquifers. In comparison, rain quickly runs off land and into the ocean. In 2015, California's snowpack was only 6 percent of normal levels.

Stanford scientists agree that the extreme atmospheric conditions responsible for diverting rain and snow from California are more likely to occur in an environment of elevated greenhouse gas emissions. That is to say, California's drought is almost certainly linked to human-caused climate change.

Policy and Infrastructure Solutions

Dams Some fiscal conservatives have suggested infrastructural solutions to the drought: aqueducts and dams to collect river runoff before it reaches the ocean. Supporters say increased water storage would provide relief during periods of drought. This approach would require the elimination of environmental regulations that require water to be used for the health of ecosystems, rather than for human activities.

However, dams are not the best solution for California's drought. According to Friends of the River, a California-based advocacy organization, the five proposed dam projects would cost $9 billion while only providing 1 percent of the state's annual needs. Furthermore, dams do not increase the amount of water available -- they simply store water during times of plenty for use during times of drought. Yet in an environment of climate change, it is impossible to know when (or if) California's rivers will resume flowing.

Desalination Plants Desalination (or "desalinization") is the process of removing salt from water, rendering it potable. Nearly 98 percent of the world's water is salt water, compared to 2.5 percent for fresh water. Through a process of reverse osmosis,  desalination plants can make this plentiful salt water suitable for human consumption.

It is a costly and energy-intensive solution, however. In Santa Barbara, it costs about $300 to produce an acre foot of water, compared to an estimated $1,700 per acre foot for desalination plants. Desalination plants are also harmful to the environment, absorbing microscopic marine life and minerals while releasing more salt into the ocean. For these reasons, only .2% of the water consumed worldwide is desalinated salt water.

Agriculture Avocados are the subject of many human interest drought articles these days. The green superfood is a major product for California, with one billion pounds sold annually. However, it takes 72 gallons of water to grow a pound of avocados, compared to nine gallons for a pound of tomatoes. That math doesn't add up for a state in the middle of a historic drought.

As an avocado lover, I hate to say it -- but it's time for agriculture to bear the brunt of the drought's costs. Agriculture consumes 80 percent of the state's water, while contributing only 2 percent to GDP. Reducing water consumption by mere percentages in the agriculture sector would make a bigger impact than dams, desalination plants, and human conservation efforts combined.

Farmers need to find more efficient methods of growing their crops -- and dramatically reduce the production of crops like rice, almonds and avocados. We need to reform "use-it-or-lose-it" water rights laws that provide legal rights to all water on a landowner's property, while relinquishing the rights if the water is not used. The agriculture sector cannot be exempt from executive orders to reduce water use. Finally, a water tax is a risky political move, but it would provide an enormous incentive for businesses to find innovative solutions for reducing water consumption.

Of course, this is a simplified analysis of a highly-complicated problem. But it was a great learning experience for me, and I'm grateful to the "Turn Down the Heat" course for that!