Capitol Hill Blue Forums Political Issues Climate Change and Environmental Issues Billions face food shortages, study warns

Billions face food shortages, study warns
• Climate change may ruin farming in tropics by 2100
• Record temperatures to become normal in Europe

Ian Sample, science correspondent
The Guardian, Friday 9 January 2009

Half of the world's population could face severe food shortages by the end of the century as rising temperatures take their toll on farmers' crops, scientists have warned.

Harvests of staple food crops such as rice and maize could fall by between 20% and 40% as a result of higher temperatures during the growing season in the tropics and subtropics. Warmer temperatures in the region are also expected to increase the risk of drought, cutting crop losses further, according to a new study.

The worst of the food shortages are expected to hit the poor, densely inhabited regions of the equatorial belt, where demand for food is already soaring because of a rapid growth in population.

A study in the US journal Science found there was a 90% chance that by the end of the century, the coolest temperatures in the tropics during the crop growing season would exceed the hottest temperatures recorded between 1900 and 2006.

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In many countries, a combination of poor farming practices and deforestation, exacerbated by climate change, may steadily degrade soil fertility, leaving vast areas unsuitable for crops or grazing. In 2007, scientists warned that poor soil fertility meant a global food crisis was likely in the next half-century.
The Guardian UK

I'm thinking poor farming practices and lack of water will make life hell for a lot of people in the years to come.

I live in the desert. Arizona grows loads of vegetable crops commercially. It gets hot here and the sun will burn everything up unless it gets water.

Home gardens in the desert do well and can easily feed more than a family of four if you have the right soil mix, the right amount of water, and if you plant the right crop at the right time.

You can't grow stink on a monkey in Florida. Soil? We don't have soil, we have sand. You know those horrible tasteless tomatoes you get in the off season and at fast food places? We grow those.
A successful garden here has to constantly be pumped full of organics and fertilizer. The results are still less than satisfying.

Agreed that soil/water is at the heart, but I would add in the effect of population growth.

Can't help recalling "Soylent Green", and Swift's "Modest Proposal".

Were I to build the perfect society, I might design it with a population cap.

... or perhaps, more than we understand... the earth is self limiting?

BTW, Written in 1966, the Soylent Green novel, is set in the year 2022... Prescient?

We have lived during, possibly, the most remarkable time in human history. Never before have so many had so much and to the ultimate detriment of the species.

Eight of the many reasons such studies are fatally flawed:

First point. Increased CO2 leads to higher crop yields. Even the pessimists quote increases from 8-25% from CO2 fertilization by itself. I've seen studies with values ranging from 15-45%. Higher CO2 = higher plant growth.

Second point. These results are based on models such as CERES-Maize, using predicted temperature/rainfall changes. But if you look at the results, you'll see something odd. Across the entire world, every single nation shows declining production from climate change. Every single one. Climate change predicts some areas will warm, some will cool. Some will get slightly more rain, some less. But such models assume that every spot in the planet is already at optimum grain growing conditions. If more rain is predicted, they use a negative function for flood, rot, etc damage. If less rain is predicted, they reduce the yield also -- but don't add in increases due to less rain losses. The assumption is laughable on its face. Even if these changes DID mean less production globally, there would still be many, many areas for which a little more(less) rain or a little higher(lower) temperature would be BETTER for agriculture. In short, the assumption that every square inch of the planet is already "optimum" for growing food is tripe.

Third point. Most studies don't attempt to dispute that, in at least some nations (the US, Canada, Argentina, Australia, etc) that total grain production will, when CO2 fertilization is considered, be **higher**. Their negative effects are only when losses in Africa and other third-world nations are added in. And, as I've demonstrated, those values are highly unrealistic.

Fourth point. The entire premise of this modelling is based on another model, a GCM. Is that reliable? We already have substantial evidence to demonstrate that climat sensitivity is being grossly ovestated. Climate models have continually downscaled their sensitivity over time. Hansen/GISS in the 1980s was claiming sensitivities of 6C+. Today, the IPCC says 3C..and other research says less than half that.

Fifth point. The models predict future conditions, but assume year-2000 mitigation technologies (even lower, for third-world nations). In 2080, will farmers be better equipped to deal with, say, a 10% loss in rainfall than they are today? Even the simple expedient of a few large-scale desalinator plants can essentially eliminate aridity effects in most nations.

Sixth point. Model fails entirely to consider increases in crop yields due to biotechnology, or even simple plant husbandry (breeding for better yields). We've seen astronomical gains from this in just the last 100 years alone. There's no reason to believe they'll stop overnight.

Seventh point. The simple transfer of First-world farming methods to the Third World would increase global food production by several times what these predicted losses are. Currently, the First world produces 2-3 tons food/acre/year. Most of the Third World about half that...simply because they don't use our high-yield strains and farming methods.

Eigth point. The amount of cultivated land in most First-World nations runs between 5 and 30%. In the US, its only 20%...and has been declining for many years. We need less and less land each year to feed more and more people...despite 150 years of climate change. But even ignoring all the other objections, the simple expedient of farming a slightly larger percentage would more than compensate for all the hypothesized losses.

How many more points do you need?

In the 1800s, predictions were rife that the world would be starving by 1900. In 1960, a flurry of scientists and government bodies claimed with total assurance that food production would soon decline and, by the year 2000, billions would be starving to death.

Today, we see the same fearmongering. Deja vu all over again. Memories are short.

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Given that California is the single largest producer of many food items, these changes could be catastrophic to food production.


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