Wednesday, April 4, 2012

Climate Matters. D is for Desertification

Post for the letter D in the A-Z Blogging Challenge 2012. Link in the sidebar.

Desertification is when once fertile lands degrade and become extremely dry and unproductive. It is known to be caused by human acitivies like overgrazing as well as by climate change. It is a huge problem worldwide with many negative consequences.
Vegetation can stabilise sand dunes.
Deserts expand and contract independent of human activities, they can stabilise as vegetation takes root and expand as grasses, shrubs and trees are removed. Desertification has affected civilisations for eons and led to displacement of peoples as lands become uninhabitable and unable to support human needs.

Dryland ecosystems are extremely fragile. As populations increase and more people need to be fed, communities in dryland areas place increasing demands on the land by overgrazing and overcultivation – more people need to be fed from less arrable land. The soil can become increasingly salty, leading to poorer crop yeilds – malnutrition is often the outcome. Stressed soil is less able to absorb water, which in turn leads to an increase in erosion, which makes the land even less useful for often already marginalised communities.

In many countries where meat consumption has traditionally been low, there has been a push to increase their meat consumption either by importing cattle or increasing the size of their own herds.
Cattle trample fragile grasslands and the lack of vegetation leads to erosion and further loss of topsoil when there is rain. Cattle also muddy and foul precious drinking water as fencing in many developing nations is often inadequate.

When grasses are inadequate to feed the cattle, grain intended for human consumption is fed to the cattle which represent the families wealth. Land which wasn’t particularly productive at the best of times is degraded even further leading to subsistence lifestyles or displacement – peoples move to cities hoping to find work which is increasingly scarce.

Cattle and other ruminants also emit a huge amount of methane (ie they fart) which contributes substantially to the greenhouse gases entering the atmosphere. It’s estimated that cattle emit similar levels of greenhouse gasses as does industry.

Even in wealthy countries like Australia, there are problems with salinity and erosion due to overgrazing and inappropriate farming methods in the past. The problems in developing countries are even greater due to lack of political interest in marginalised groups and the scale of the problem.

Last year I wrote about Danger, Depression and Doctors for D in my theme of workplace bullying. Here.


mybabyjohn/Delores said...

A very interesting series.

Betty Alark said...

Hi, Sue!

Hope you are enjoyng the challenge, I am!

I like your "D" topic! I've always had an interest on the subject matter. So I learned something today!
Thank you!

Cathy said...

Stopping by from the A-Z challenge. I enjoyed reading your posts. I agree that we're experiencing global climate change. In our area, it's getting colder. In fact, it was snowing heavily when I got up this morning. It's still snowing now at noon, and we have 2-3" on the ground. That is terribly unusual for us on April 4. They predict our average temperature will be 1-degree lower than normal overall in 2012.

sue said...

Delores, interesting is what I'd hoped to make this topic, so thankyou!

Betty, I've got my running shoes on to do a quick catch up! Great that you learned something, thanks :)

Cathy, there's so much complexity with the whole topic: hotter here, colder there, just plain out of kilter elsewhere. Very challenging times we're experiencing.

Hilary Melton-Butcher said...

Hi Sue .. it's the jet streams and stellar winds that affect our planet too .. in fact I watched an extremely interesting programme - on how the British and Britain happened to be in the right place at the right time in the 1700s ... the earth had created the right environment - coal, Britain had an economic power base, which was growing very quickly, they also had entrepreneurial people who invented steam, looms etc etc .. which all fuelled the Empire as such.

Whereas the Chinese couldn't get out of their loess rich soils, because the countryside is full of rapids, high mountain ranges - and thus their rulers - Terracotta Army time ... couldn't invade anywhere;

Then the Aus .. their rich soils blew off the land too with a climate whereby it's too dry to farm as we (modern day peoples) would like to do.

I made notes .. !! Fascinating how the wind has over time made a very big difference to life on earth .. as glaciation or melt might do in future times ..

However going back to hunter-gatherer times we would be healthier and the land could provide for all - if greed, power and control didn't take over ..

We're going to have desertification down here shortly - very little rain!! Short-term problem .. and people will be up in arms without thinking .. the whys and wherefores ..

Cheers - Hilary

sue said...

Hilary, another interesting book called (I think) "Dust". Fascinating stuff, blowing around the world throughout time, changing location, but always there.

Not much would need to happen to make Britain an extremely challenging climate to survive - winds and ocean currents play such an important role. The interlinking of it all is so complex. Layers and layers to get your head around.