Week 6 - Impacts on human systems

Last week was pretty hard to understand as a lot of the glacier information was hard to work out and ocean acidification was new to me, so there was a lot going on to fill up my brain. Impacts on the human environment and systems is more connected to what we see everyday and links in with studies I did at university back in 2000...

Impacts on human systems

In the UK, the building industry is responsible for over 50% of carbon emissions, and in some economically-developed countries, the figure is even higher. There are 3 concepts:

Urban heat islands

This was first discovered by the large expanse of buildings in our urban areas are very efficient at absorbing and reflecting heat. The larger and taller the buildings, the more heat they are capable of trapping at street level bouncing backwards and forwards between buildings. Buildings block wind, which inhibits cooling by convection and increased drainage of urban areas, sewers carry away water, preventing evaporation.

Heat islands are not a newly-discovered phenomenon. Indeed, using simple mercury thermometers, weather watchers have noticed for some two centuries that cities tend to be warmer than surrounding rural areas. The island is affected but the size of the city, population, number of building etc.

Heat waves

A heat wave is a period of hot weather prolonged over several days. In 2003 almost 70, 000 people died in Europe due to the hot weather either from hyperthermia, dehydration and heat stroke. A large proportion of people also died at the top floor of high rise building which can be linked to the concept of thermal comfort.

Thermal comfort

Your body is producing approximately 100 watts of heat even just sitting down and this amount increases as you become more active.  As you get hotter you adjust your environment such as remove layers of clothes, open a window, fan cold air on you or perspire. The rate of heat loss depends on the environmental conditions, temperature, humidity, and air movement.

Climate change and food security

The global population stands at 7 billion. We predict by 2050, we will reach 9.2 billion people on this planet. 86% of these people will be living in less economically developed countries so the challenge is how we will feed everyone! The four staple foods are rice, maize, wheat and potatoes. These provide essential carbohydrates in our diet with rice being the most important because it provides the main daily calorie intake for 50% of the world's population. Because of the growing population we need to ensure that food production doubles by 2050 and we need to ensure there is a secure system for this to happen.

There are a number of factors which are affecting food production/crops, which are largely due to climate change. These include drought, changing rainfall patterns, flooding, fires and crop diseases.

Crop disease

Since the 1960s, we've undergone what is termed the Green Revolution. 

1. The Green Revolution refers to a series of research, and development, and technology transfer initiatives, occurring between the 1940s and the late 1960s, that increased agricultural production worldwide, particularly in the developing world, beginning most markedly in the late 1960s.

The Green Revolution haas meant the increased use of fertilisers, herbicides, pesticides, and fungicides, as well as greater farm mechanisation and intensification. It has also meant the introduction of high yielding varieties of our crops in vast hectarages of monocultures. If pathogens are introduced to these monoculture environments they can wipe out an entire crop in one go. Examples of this happening are:

Ash dieback fungus
Irish potato famine

Fungi is becoming a big problem pathogen and there are strains of fungi which are affecting our staple food supply (rice/wheat/maize). And the cost of loss of crop caused by these fungi to the global economy is $60 billion US per annum. There is a gradual shift of pathogens affecting crops towards the higher latitudes. Since 1960 the mean shift has been in the region of three kilometres per year. Fungi are moving over 7 kilometres per year polewards in a warming world.

Reflection:

What are the most important themes you have learned this week?

Food security - i'd never hear of this before and seems like it's a pretty big thing which we really need to look out on a global scale. It's shocking how much we are producing and wasting whilst people in other countries are starving

What aspect of this week did you find difficult?

Nothing too bad this week, I suppose i didn't initially get some of the stuff mentioned on the video for food security but once i read the transcript and read other articles it made more sense

What did you find most interesting? And why?

The heat wave stuff and how the urban environment is affected.

Was there something that you learned this week that prompted you to do your own research?

Food security - looked at some news articles to strengthen my understanding and out things in perspective

Are there any web sites or other online resource that you found particularly useful in furthering your knowledge and understanding?

http://www.nasa.gov/topics/earth/features/heat-island-sprawl.html
http://earthobservatory.nasa.gov/IOTD/view.php?id=36227
http://www.theguardian.com/environment/2012/sep/19/climate-change-affect-food-production
http://www.foodsecurity.ac.uk/index.html