Two new studies using data from NASA Gravity Recovery and Climate Experiment (GRACE) satellites show that human consumption is rapidly draining some of the world’s largest groundwater basins, yet there is little to no accurate data about how much water remains in them. This means that the world’s largest underground aquifers, on which hundreds of millions of people rely for fresh water, are being depleted at an accelerated rate – a rate of depletion which has pushed these aquifers beyond their sustainability tipping points: During the 10-year study period, more water was removed than replaced.

Lack of potable water is a huge problem in many developing countries. According to UNICEF, 783 million people worldwide are without improved drinking water, and the World Health Organization estimates that lack of proper drinking water causes 1.6 million deaths each year from diarrheal and parasitic diseases. Part of the problem is that many of these countries must import expensive chemicals to clarify the water, limiting the amount they can afford to produce. What would happen if a common tree had the potential to turn cloudy, contaminated water into clean, safe drinking water for millions in need? Researchers are hoping to find out using the seeds of the Moringa oleifera tree.

Global security analysts have warned for some time now that water scarcity due to climate change will be used as a tool of war in regions with poor governance. The on-going wars in Iraq and Syria provide the first examples of the strategic and tactical use of water as a tool of war, as militant groups operating in both countries – and, in Syria, to government of Bashar al-Assad — have been using the denial of water as a tool against areas and populations they regard as hostile. Last month ISIS militants captured a dam on the Euphrates River to the north of the Iraqi city of Ramadi, and last week they began closing most of its gates, cutting water supplies to pro-government towns and villages downstream.

The California drought is expected to be worse for the state’s agricultural economy this year because of reduced water availability, according to a new study. Farmers will have 2.7 million acre-feet less surface water than they would in a normal water year — about a 33 percent loss of water supply, on average. Reduced availability of water will cause farmers to fallow roughly 560,000 acres, or 6 to 7 percent of California’s average annual irrigated cropland. The drought is estimated to cause direct costs of $1.8 billion — about 4 percent of California’s $45 billion agricultural economy. When the spillover effect of agriculture on the state’s other economic sectors is calculated, the total cost of this year’s drought on California’s economy is $2.7 billion and the loss of about 18,600 full- and part-time jobs.

A recent article highlights the widening gap of inequality between the wealthy and the poor of California, specifically in relation to the State’s current drought. The authors discuss what has caused these inequalities to expand — the outdated and unsupervised water regulations still currently used, combined with decentralized local control means using and sourcing water comes down to the simple matter of what people can and cannot afford.

Although record low precipitation has been the main driver of one of the worst droughts in California history, abnormally high temperatures have also played an important role in, according to a recent study by the U.S. Geological Survey and university partners. Experiments with a hydrologic model for the period October 2013-September 2014 showed that if the air temperatures had been cooler, similar to the 1916-2012 average, there would have been an 86 percent chance that the winter snowpack would have been greater, the spring-summer runoff higher, and the spring-summer soil moisture deficits smaller.

Californians for Population Stabilization (CAPS), an anti-immigration environmentalist group, has made a splash with provocative advertisements which feature a young child asking, “If Californians are having fewer children, why isn’t there enough water?” The ad is part of a broader media campaign by the organization which blames immigrant populations for the historic drought in the state. CAPS is calling for stricter enforcement of immigration laws on environmental grounds: it argues that the state’s natural resources cannot sustain the high levels immigration-driven population growth of recent decades. Drought experts and climatologists dismiss CAPS’s claims about the connection between immigration and drought as laughable.

California is undergoing a record-setting drought that began in 2012, the worst in at least 1,200 years. California and other southwestern states have suffered through multi-year droughts in the past, but how does climate change figure into what’s happening now? Can scientists separate the effect of rising greenhouse gas levels on the current drought from other factors? Detecting and attributing observed or projected impacts to man-caused climate change is not an easy task. But there is some supporting evidence from improving numerical climate models and the record of several diverse meteorological and hydrological events already happening, including heat waves, flooding, or droughts. Scientists can run climate model experiments that include only natural variability and then include manmade factors, such as greenhouse gases. These tools serve to highlight and distinguish the dominant mechanisms responsible for particular air circulation characteristics. These climate model simulations show that the extreme and persistent circulation patterns that have caused droughts on the West Coast this century are due to anthropogenic external forces, not natural causes. Studies suggest that climate change might give rise to a new climate regime, one in which the years of low precipitation will be accompanied by warm conditions, creating the aforementioned “warm drought.”

California is in the fourth year of an historic drought. It’s now so bad that state water authorities canceled the last monthly measurement of the snowpack in the Sierra Nevada. There wasn’t enough snow to even bother trying. The situation compelled Governor Jerry Brown to impose emergency water-conservation measures that will require a 25 percent cut in urban water use over the next year. The water footprint of the state’s higher education system is substantial: there are ten University of California campuses, twenty-three California State University campuses, and 112 California community colleges. Yet the university system is putting in place a number of measures to conserve water. Municipalities, too, will need to implement similar measures to meet the mandates and adapt to this prolonged drought.