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As Clouds Head for the Poles, Time to Prepare for Food and Water Shocks

A changing climate means less rain and lower water supplies in regions where many people live and much of the planet’s food is produced: the mid-latitudes of the Northern and Southern hemispheres, including the U.S. Southwest, southern Europe and parts of the Middle East, southern Africa, Australia and Chile. As WRI-Aqueduct’s future scenarios for water supply show, diminished water supplies will be apparent in these areas by 2020 – less than four years away -- and are expected to grow worse by 2030 and 2040.

Now a new study in the journal Nature provides some of the first evidence that this widely-predicted phenomenon – the movement of clouds and rainfall from the mid-latitudes towards the North and South poles -- is already taking place. Just like the retreat of glaciers and polar sea ice, now clouds and rain are retreating poleward.

This will have huge implications for agricultural production, industrial and energy output, and municipal water provisioning. Many irrigated agricultural areas are already facing water stress. The climate-driven shift of clouds and rain – known as Hadley Cell expansion – will put those areas under even greater stress in the future. Rain-fed agriculture, which many poor people depend upon, will also suffer as a result of reduced rainfall in the mid-latitude regions.

A recent WRI study finds that sub-Saharan Africa will need to more than triple crop production by 2050 in order to feed its growing population. This hard-to-reach target will become more difficult in places like southern Africa and the western Sahel, where water supply is projected to fall.

In addition to worsening water stress and undermining food security, decreasing water supply in the world’s mid-latitudes may also help destabilize nations in these regions, adding to pre-existing political tensions, and helping contribute to armed conflict and migration, as we have seen in places like Syria.

What can we do now to prepare for these future climate change threats? First, we need to better understand the nexus of water risk and food security. WRI-Aqueduct, with support from Danida (the Danish development aid agency) and the Skoll Global Threats Fund, is developing an online tool that will help policymakers identify global water risk and food security hot spots. The risks are not always obvious. A country can be relatively water-secure within its own borders, but still be highly dependent on food imports, some of which come from countries whose agricultural production systems face very high levels of water risk. In poor countries, price spikes can put food out of the reach of many citizens. The new WRI Aqueduct tool aims to shed light on these types of threats.

Vulnerable countries also need to take steps now to make their food production systems more productive and resilient in the face of climate change. By improving land and water management practices, for example, farmers in Africa have been able to restore soil fertility, capture rainfall before it runs off farm fields, and sustainably increase yields on their farms.  A recent WRI study estimates that improving land and water management on just 25 percent of sub-Saharan Africa’s 300 million hectares (more than 740 million acres) of prime cropland would result in an additional 22 million tons of food.

Tools and mechanisms can help vulnerable countries cope with drought and famine. The Famine Early Warning Systems Network (FEWS NET), for example, is a leading provider of early warning and analysis on food insecurity. Also important are insurance and subsidy systems that can help support farmers when crops fail.

The shifting of cloud and rainfall patterns around the globe are just one more visible sign of the effects of climate change. What we need to begin doing in response is to anticipate the location and magnitude of these effects, and build resilience into the lives and livelihoods of those who will be most vulnerable.


We will never be able to feed a constantly GROWING population, population growth must end & it will.
Because we have allowed our population to go so far into overshoot, we are condemned to collapse because our ability to feed ourselves will decline with climate change, decline in fossil resources, soil quality & declining availability of fresh, clean, water.
We should have started decades ago to stop growth using education, emancipation of women, easy to get & use birth control, sex education & abortion.
The sustainable world population without fossil resources is about 1 billion, we have 7.4 billion & still growing, for now.
There are no "shortages", there is excess demand.

Population growth is a concern, but the way we grow and otherwise produce and distribute food/agriculture needs to change. We've been using wasteful inefficient methods. This is a big topic and there are many different ways this can and will be done, but I agree with the United Nation's report encouraging more support for small scale farmers to build strong local food systems.

Disagree vehemently with parts and agree vehemently with other parts..

While the population is still growing it is slowing and yes the peak is estimated at 9.4 billions and by the end of the 21st century it is expected to have reduced back to around 7 billion.

The spread of education and education of women is driving the falling birthrates around the world and yes there are a limited number of nations where birthrates are still increasing but they are expected to switch into falling birthrates. Evidence shows that even one year of education for a female results in fewer actual pregnancy's, live births and survival of those children. Education of women is generating a negative response among some of the religious fundamentalists and forms a key part of their platform of terror against women.

The degradation of the environment is a serious problem and it isn't helped with the use of GMO's that encourage vast monocultural farming practices, these raise the risk of failure and successful disease and pest attacks that will overwhelm our defenses and certainly.

Given that all countries waste close to 50% of the food produced either post processing and manufacturing or post harvest before despatch to consumers reductions in this will ensure more than adequate food for all. But with the recognition that supply and deman are often in different locations and then the lack of money to purchase creates another problem regarding distribution.

With the shift towards renewable energy resources and improved energy efficiencies demand for fossil fuel sourced energy is declining and we now live with the happy prospect of leaving fossil fuel resources in the ground.

The big fly in the ointment is as you point out Climate Change and how and where it impacts will play a significant role in determining outcomes of food and water security.

yeah, but that is only one side of the problem and it is very comfortable for "us" to emphasize that "they" should have less children. but the other side is the issue with extreme inequality in access to resources - while westerners consume tons of senseless products (and therefore burn a lot of fossils and use o lot of water and soil), other people live in poverty (which doesn't need to mean they are unhappy). So first of all we have to do something with extreme consumerism i the west...

Yes, an ever-growing population is the rarely acknowledged root cause of severe climate change. World population has been growing less rapidly in recent years but is still growing far too quickly. Sadly, we've passed the time when clamping the brakes on population growth could have averted the drastic changes we will soon experience. Now, it is essential to act directly against CO2 and methane emissions as quickly as possible (as well as continuing to move toward ZPG and hopefully population reductions).

Hit the nail on the head with that comment!

How do you arrive at the 1 billion figure? As far as I've understood the number is far higher.

You mention sub-Saharan Africa needing to triple crop production, those regions at the Equator and slightly above and below are projected to become almost too hot live in in the coming decades. There will be increased migratory movements away from these areas.

We were warned about this when the first Earth Day was held in 1970 It became core curriculum in college biology and social sciences. Then the oil shocks hit and the economy tanked and environmentalism took a back seat.
Nothing has changed from the predictions of the 70s. We will experience hyper demand, shortages and environmental degredation as it was predicted. We need to revisit and change the direction we are heading. Fast.

The Near East, with North Africa and towards Pakistan and Afghanistan and Pakistan on the other side will be most severely hit. Groundwater depletion is already a very serious issue, and in this area there is no incentive to reduce population growth. I am in Afghanistan, and they don't believe in evolution, and about population, they always say "God will provide." If migration and wars are a problem now, wait a couple decades!!

Very well said. Population HAS to decline; it would be much better if it were planned and voluntary.

How do you figure that 1 billion is the fossil free sustainable population? Is energy subsidy the only limiter?

Wow Julia, that is the most thoroughly condensed really bad news I've seen in a while, Extremely well put. I agree with every word of it. NO need to comment, just read Julia's. It says it all.

"There are no shortages; there is excess demand." Right on the money.

Unfortunately, you are preaching to the choir. It is a desperate state of affairs when the very same population that opts out of liberalism and its principles is deaf to the solution. Without a major conversion experience and zero growth population or a major plague, the projected outcome is only a matter of time.

Without disputing the central claims made, I wish to make two points. One, regarding 'demand'. Much of what is grown, like the acres and acres of corn for biofuels and syrup, serves almost zero nutritional needs. It does satisfy the 'demand' on hospitals for treatment of type 2 diabetes for example. My point: education about diet matters. Second, rather than always go on and on about 'poor Africa', why not focus on the disastrous practices in the Global North - such as all across the Ogallala aquifer where there is an absolutely ridiculous race to the last drop.

Those of us who were born around 1940 will remember the world before people. It was hugely different. And the stress felt at the level of the collective unconscious was much less than it is today.

Population size is not likely to become the problem projected. Our ability to protect the human race from epidemics as we have in the past with antibiotics is precipitously ending. At the same time, new viral epidemics are bearing down on us. In addition, changing nutrition sources and shortages will be causing the populations to have reduced resistance. We won't be experiencing the same kind of linear increases in population as these phenomena accelerate on their own trajectories. We could just as easily wish we had more children than we are having. Increasing the human race may be a new world objective in a few decades.

This Hadley cell expansion is really a decrease in the Polar Hadley Cell as the equatorial and Ferrel cells expand northward. The Polar Hadley cell is powered by air over the Arctic not being heated from below as is the case in the rest of the world and radiating heat to space. This heavy air then sinks and spreads south to rise again around 60 degrees North - the Polar Hadley Cell. When the Arctic ocean is sufficiently open water to absorb sufficient heat, it will heat the air from below and the Arctic will become an area of rising air, especially in the fall as the surrounding land rapidly cools off. As it is, the polar jet stream weakens in the summer and strengthens in the winter. Its strength is a function of the rotational speed of the Polar and the Ferrel Hadley cell. This shows clearly the weakening of the Polar Hadley cell, even now, in the summer. So what can we expect to see. At some point, instead of the gradual creep of the climate zones northward, we should see a sudden lurch and even the disappearance of the Polar Hadley cell and the Northern Jet Stream. We will have essentially a two cell system in the Northern Hemisphere. This will draw large amounts of heat from the south and further exacerbate the melting of sea ice and permafrost and further encourage the establishment of this new climate regime.

To bring a different aspect into focus:
Concerning population growth, it is very much dependent on the mere availability of contraceptives, look e.g. here: If the numbers are correct, the number of unintended pregnancies per year in the developing world alone equals more or less the world population growth rate.

Biodiversity is the essential core underpinning all if this. We must integrate biodiversity protection across all sectoral areas- climate change, food security, health, governance, economis development. We must stop the silo approach to development and integrate biodiversity!

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