environment - Tag Archive

What actually is GM Food?

6 Replies Jonny Hankins

Last week I gave some statistics about GM food production both in the USA and worldwide, and this week I wanted to consider what genetic modification actually is. It appears to me that confusion reigns when addressing issues surrounding GM, so I would like to try and clarify a few issues.

GM exists in plants but also in animals as the salmon link showed last week (not currently approved for consumption), but we tend to associate it mainly with crops, so what does it entail?

In relation to the biggest crops that I mentioned last week, soybean, cotton and corn, there are 2 distinctly different approaches. The first is herbicide tolerance (HT) and the second insect resistance (Bt). In other cases nutritional changes have been made, but the major cash crops are based around the following approaches.

Herbicide-tolerant (HT) crops are developed to survive application of specific herbicides that previously would have destroyed the crop along with the targeted weeds. So you can plant your seeds and spray a herbicide that kills everything apart from your desired crop.

Herbicides target key enzymes in the plant metabolic pathway, which disrupt plant food production and eventually kill it. Genetic modification creates a degree of tolerance to the broad-spectrum herbicides – in particular glyphosate and glufosinate – which will control most other green plants.

Industrial Herbicide Techniques

Industrial Herbicide spreading Techniques

1. Glyphosate-tolerant crops
Glyphosate herbicide kills plants by blocking the EPSPS enzyme, an enzyme involved in the biosynthesis of aromatic amino acids, vitamins and many secondary plant metabolites.  There are several ways by which crops can be modified to be glyphosate-tolerant. One strategy is to incorporate a soil bacterium gene that produces a glyphosate-tolerant form of EPSPS. Another way is to incorporate a different soil bacterium gene that produces a glyphosate degrading enzyme.

2. Glufosinate-tolerant crops
Glufosinate herbicides contain the active ingredient phosphinothricin, which kills plants by blocking the enzyme responsible for nitrogen metabolism and for detoxifying ammonia, a by-product of plant metabolism. Crops modified to tolerate glufosinate contain a bacterial gene that produces an enzyme that detoxifies phosphonothricin and prevents it from doing damage.

The developers argue that use of this type of seeds cuts fuel usage and tilling as there are fewer weeds, (tilling leads to top soil loss as it is blown in the wind). They also argue that GM production has led to less herbicide use, and this seems to currently be the case.

Unfortunately one effect of this mass usage seems to be the development of ‘superweeds’, that are becoming resistant to theses herbicides. Farmers have had to address this problem by using more and different types of herbicide, with the journal Nature recently reporting a Pennsylvania State University research article that claims that pesticide use will increase dramatically in the very near future as a result, questioning the sustainability of the process. Something similar to the present antibiotics resistance problem that we are seeing in the human population. It should also be noted that the use of broad spectrum herbicides has grown as GM usage has grown, as its ease of application using the new seeds has made it more widespread, even though it only needs to be applied once.

Insect-resistant crops containing the gene from the soil bacterium Bt (Bacillus thuringiensis) have been available for corn and cotton since 1996. These bacteria produce a protein that is toxic to specific insects. Instead of the insecticide being sprayed, the plants produce the bacteria so the insects eat the plant and die.

There are risks associated with this approach as well as the advantage that farm workers are not exposed to spraying insecticides.

Invasiveness – Genetic modifications, through traditional breeding or by genetic engineering can potentially change the organism to become invasive. Few introduced organisms become invasive, yet it’s a concern for the users.

Resistance to Bt – The biggest potential risk to using Bt-crops is resistance. Farmers have taken many steps to help prevent resistance but as in the previous case it is a potentially serious problem.

Cross-contamination of genes, genes from GM crops can potentially introduce the new genes to native species.

Now I am no scientist as we all know but I presume that the human must consume the bacteria too, although scientists assure me that the bacteria is not harmful to humans or other mammals.

Much of the recent dramatic growth in GM usage can be attributed to the development of plants that offer both of these systems.

Next week I will take a look at the regulation of GM foods.

Carbon Emissions and Aviation

4 Replies Jonny Hankins

On Sunday I will be lifting off into the wild blue yonder once more for a quick scoot across the Atlantic from Boston to Dublin and on to Milan. This is a rather regular occurrence nowadays. Flying is part of my life and for the kids, who have been on more aircraft than trains.

The environmental impact of all of this folly though is tied up in a rather controversial debate. On the one hand we have those who say that airline carbon and pollution emissions is minimal, others disagree. It seems that between 2 and 5% of possible global warming type emissions come from aviation. Not a lot we might think, when we bear in mind that 10% comes from car use, and about 17% from agricultural food production, but we all eat, we do not all fly.

This year the European Union was to start taxing airlines on their carbon emissions, in line with the way they tax other industry on theirs. This might seem fair to some, not to others, particularly large airlines and countries. Here in the USA a law was passed to state that US airlines could not participate in the scheme, and so could not pay the tax. China, India and others followed, and so the scheme has been postponed.

A Modern Jet Engine

A Modern Jet Engine

So back to my flight on Sunday. Between us, I and my family will produce about 12 metric tons of carbon dioxide in our time in the air. The average European produces about 10 a year, Americans more like 19 0r 20 and the average African about 0.3 tons per year.

Oh to put things in perspective the global average is 1.3 metric tons per year per person, and the 1.1 billion people who live on the continent of Africa produces about 7% of the emissions that the 0.6 billion population of North America produce.

So taken in terms of people and not percentages, flying is extremely polluting. But people are not going to stop flying. The aviation industry is ever expanding, even vegetables fly nowadays.

One way that aircraft engineers are trying to cut down on emissions is to design lighter and more fuel efficient engines. Weight is a big problem in flying, and it is our old friend 3D printing who might come to the rescue.

A company called CFM International, a joint venture between GE Aviation and the French company Snecma, has created the LEAP engine — an acronym for “leading edge aviation propulsion” that the company hopes reflects just how innovative the new aircraft component is. LEAP has many futuristic features, including a 3-D-printed nozzle, the part of the plane responsible for burning fuel.

3D printing allows engineers to produce objects in materials that either would be too expensive or impossible to make using conventional techniques, and they can use lightweight materials or ceramics as is the case with the new CFM engine to substitute heavy metal parts. Check out this article in CNN for details.

Over the last couple of weeks an aeroplane has made a trans America flight using solar power, and this is just part of its round the world trip. A whole new concept in low carbon emission flight, although currently a bit slow.

Another possibility is to use organic jet fuel. Although this may seem strange, as long ago as 2009 Air New Zealand conducted a test flight using an organic jet fuel mix that seemed to demonstrate a 60% cut in carbon emissions.

Here is a link to an article in the New York Times about aviation and carbon developments and some more data about carbon emissions in Africa if I have tickled your interest. And as always, I am all ears.

Mining the Seabed

4 Replies Jonny Hankins

Last year I wrote about the possibility of sending robots to asteroids to mine them for their metals, and although this might sound a little far fetched there are companies that exist to promote and make the idea possible.

In this posting I would like to draw attention to proposals for mineral mining a little closer to home. The International Seabed Authority (part of the UN) released a report last week about how it intends to manage the extraction of metal rich rock from the seabed.

The sea floor contains gold, copper, manganese, cobalt and other metals, and it now seems that the mining companies have the engineering capability to harvest it. The prices are high for these metals too, so they also have some economic push to help them along.

Licenses to prospect have already been granted, so it seems only a matter of time until companies are given permission to start removing pieces of the sea floor.

A hydrothermal vent under the ocean

A Hydrothermal Vent

What they are interested in are pieces of the chimneys of hydrothermal vents which contain many of these metals in high quantities. Some estimates related to the bed of the Eastern Pacific Ocean give an idea of the amount of materials that are down there, seven billion tonnes of manganese, 340 million tonnes of nickel, 290 million tonnes of copper and 78 million tonnes of cobalt.

This is a completely new field for mining companies though, nobody has experience in this kind of work. But the only way to gain experience is through actually doing the job, so the authorities are in a tricky position. How can they give licenses to a company with no track record in the field? Surely that means accepting a trial and error system that will inevitably lead to accidents and pollution. There are plenty of recent examples of deep sea oil drilling going very wrong, and that is after many years of experience.

And these hydrothermal vents host life that only exists in the unusual conditions that they create, what will happen to those highly developed and particular creatures and plants?

So I ask the possibly false question of sustainability. We all use these minerals, they are in everything we touch but we don’t tend to think about where they come from. Mining is a dirty business in any situation, and by definition it cannot be sustainable as far as I can see because we are dealing with finite quantities of materials that will not reproduce themselves.

But should we or indeed can we draw a line? Asteroids, the seabed, the Antarctic, where next?