Tag Archives: drought

climate change threatens barley yields

A new study says climate change is likely to threaten barley yields, leading to high beer prices later in the century. I’m hoping this is wrong and we can grow hops and barley in the formerly frozen tundra of Canada and Siberia. Of course the bigger picture is about grain yields overall, and that is not just about average temperature but about extreme heat and drought.

Decreases in global beer supply due to extreme drought and heat

Beer is the most popular alcoholic beverage in the world by volume consumed, and yields of its main ingredient, barley, decline sharply in periods of extreme drought and heat. Although the frequency and severity of drought and heat extremes increase substantially in range of future climate scenarios by five Earth System Models, the vulnerability of beer supply to such extremes has never been assessed. We couple a process-based crop model (decision support system for agrotechnology transfer) and a global economic model (Global Trade Analysis Project model) to evaluate the effects of concurrent drought and heat extremes projected under a range of future climate scenarios. We find that these extreme events may cause substantial decreases in barley yields worldwide. Average yield losses range from 3% to 17% depending on the severity of the conditions. Decreases in the global supply of barley lead to proportionally larger decreases in barley used to make beer and ultimately result in dramatic regional decreases in beer consumption (for example, −32% in Argentina) and increases in beer prices (for example, +193% in Ireland). Although not the most concerning impact of future climate change, climate-related weather extremes may threaten the availability and economic accessibility of beer.

Roman emperors were assassinated during droughts

This academic paper puts it pretty simply:

lower precipitation increases the probability that Roman troops, who relied on local food supplies, starve. This pushes soldiers to mutiny, hence weakening the emperor’s support, and increasing the probability he is assassinated.

The modern lesson might be that if ecological change starts to hurt your society, it might be better (for the ruler) to keep the military well funded and let everyone else suffer.

considering local government policy in water risk

This paper is about incorporating local government and utility policies/actions in measures of water risk, which in the past have tended to focus on physical measurements. This makes sense because there are some very water scarce places that have managed their limited resources well, and there are some moderately water scarce places where political and bureaucratic mismanagement of resources have led to crises. This probably makes some sense because when the lack of water is starkly obvious (if your country is a desert for example), it is impossible to ignore whereas when the problem is only going to crop up under extreme conditions, local politicians and less competent bureaucrats can ignore it the vast majority of time and nobody will raise the alarm. Better data might help make these crises more predictable and preventable, rather than seeming to sneak up out of nowhere.

Mapping Public Water Management by Harmonizing and Sharing Corporate Water Risk Information

by Colin Strong, Paul Reig, Julian Köbel and Cindy Noe – March 2018

In response to water crises across the globe, data on biophysical conditions associated with water risk have increasingly been collected and understood. However, a complete assessment of water risk also requires an understanding of public water management. Currently there is a lack of global comparable data on public water management, leading to incomplete assessments of risk and suboptimal risk mitigation activities. To fill in that gap in data, this Technical Note proposes the creation of a global comparable geodatabase of public water management indicators to spur tangible improvements in water management. The geodatabase will be populated by crowdsourcing data through the risk assessments of multinational companies that are incentivized to share anonymized public water management as an innovative risk reduction practice.

May 2018 in Review

Most frightening stories:

Most hopeful stories:

  • There are some new ideas for detecting the potential for rapid ecological change or collapse of ecosystems.
  • Psychedelics might produce similar benefits to meditation.
  • Microgrids, renewables combined with the latest generation of batteries, are being tested in Puerto Rico.

Most interesting stories, that were not particularly frightening or hopeful, or perhaps were a mixture of both:

gaming the system in Arizona

Arizona water managers are being accused of finding a way to gain the system as climate change takes hold and there may not be enough water to fill both Lake Powell and Lake Mead.

Under a formula set by the state and the U.S. Interior Department, Lake Powell will send 9 million acre-feet to Lake Mead this year to prevent shortage, rather than the 8.23 million acre-feet it would send under normal river conditions. Each acre-foot is about 326,000 gallons and is enough to serve about two households for a year.

Conserving enough to prevent a shortage but not so much as to slow the flow from Lake Powell represents a “sweet spot,” CAP argued, in language that has now alarmed upstream water officials…

CAP’s “manipulation of demands in order to take advantage of the supposed ‘sweet spot’ in Lake Powell water releases undermines (regional conservation), and is unacceptable,” Denver Water CEO James Lochhead wrote.

Phoenix’s water supply

Phoenix wasn’t on the recent list I posted about the cities most likely to experience a serious water crisis, but maybe it should have been. According to The Guardian:

Phoenix gets less than eight inches of rainfall each year; most of the water supply for central and southern Arizona is pumped from Lake Mead, fed by the Colorado river over 300 miles away…

That river is drying up. This winter, snow in the Rocky Mountains, which feeds the Colorado, was 70% lower than average. Last month, the US government calculated that two thirds of Arizona is currently facing severe to extreme drought…

The Phoenix area draws from groundwater, from small rivers to the east, and from the mighty Colorado. The Hoover Dam holds much of the Colorado’s flow in the vast Lake Mead reservoir, but the river itself is sorely depleted. That water has now dropped to within a few feet of levels that California, Nevada and Arizona, which all rely on it, count as official shortages. Lake Powell, the reservoir at the other end of the Grand Canyon, similarly averages half its historic levels.

Let’s review – snowmelt, rainfall, and groundwater all disappearing, and the city continues to grow.

February 2018 in Review

Most frightening stories:

  • A general rule across many types of wildlife is that their range after urbanization decreases to between one-half and one-third of what it was before urbanization.
  • The Cuban sonic attacks are real. At least, the people who experienced them have real brain damage, even if we still don’t know what technology did the damage.
  • Cape Town will probably not be the last major city to run out of water.

Most hopeful stories:

Most interesting stories, that were not particularly frightening or hopeful, or perhaps were a mixture of both:

January 2018 in Review

Most frightening stories:

  • Larry Summers says we have a better than even chance of recession in the next three years. Sounds bad, but I wonder what that stat would look like for any randomly chosen three year period in modern history.
  • The United States is involved in at least seven wars: Afghanistan, Iraq, Syria, Yemen, Libya, Somalia, and Pakistan. Nuclear deterrence may not actually the work.
  • Cape Town, South Africa is in imminent danger of running out of water. Longer term, there are serious concerns about snowpack-dependent water supplies serving large urban populations in Asia and western North America.

Most hopeful stories:

Most interesting stories, that were not particularly frightening or hopeful, or perhaps were a mixture of both: