Saturday, 30 January 2016

MINDMAP



It'sreally important to think about how organize your ideas because a good organisation can make easier to undertand a topic.


I have found some interesting pages that allow me to elaborate a MIND MAP online.
You can export your mind map as .pdf file .png file, print it or save it.


mindmapfree.com/

https://www.mindmup.com/


You are probably wondering what a mind map is so, a mind map is a diagram used to visually organize information. A mind map is often created around a single concept, written in the center of a blank landscape page, to which associated representations of ideas such as images, words and parts of words are added. Major ideas are connected directly to the central concept, and other ideas branch out from those.
 


For me It's a extraordinary way to organize my ideas about the topic I have been studing.


I created this two mind maps about the topics studied this first week of the course. I hope they will be useful for you.









Thursday, 28 January 2016

REFLECTION

At the end of the firs week of this course I test my knoledge of the key principle of climate change and the climate system. It was not difficult to answer the questions and I was certainly got that completely right.






We can reflect on these key questions:

  • What are the key scientific principles that explain climate change including the greenhouse (blanket) effect?
  • What are the key feedback mechanisms that help to explain why our climate is able to “self-regulate”?
  • How can our climate be conceptualised as a system containing a series of components that interact with one another?


Also consider:


  • What are the most important themes you have learned this week?
  • What aspect of this week did you find difficult?
  • What did you find most interesting? And why?
  • Was there something that you learned this week that prompted you to do your own research?



In my opinion, this week was really interesting. The NASA's article was really useful to understand how the Earth is covered with a blanket which is in fact made up of greenhouse gases, of which water vapour is one of the most important. What attracted my attention was the idea of the interaction of the different feefback (positive and negative) mechanisms whereby the climate system is able to self-regulate.

Finally, I just want to say that I love to learn new things and this is a new challenge for me because english is not my mother tongue so, some of the different issues were a bit difficult for me to understand at first, but It encourages me to do my best.



Looking forward to next week
.

THE CLIMATE SYSTEM, FEEDBACKS, CYCLES AND SELF-REGULATION

Our climate is a system that it is controlled by positive and negative feedbacks as well as natural cycles.

As a system, we can distinguish 5 key components ( the atmosphere, hydrosphere, biosphere, cryosphere and lithosphere ). These components intetract between them through a series of cycles that link every component to another.

 
There are a lot of natural cycles, but a good example is the water cycle.In the picture below you can observe how it works.



To determine the climate state of the Earth is needed to undesrtand the feedbacks that operate in the climate system. There are 3 key feedbacks, water vapour feedback, ice albedo feedback and the radiation feedback.

The water vapor feedback is a positive feedback (in a mathematical way) and has three components: temperature, evaporation and water vapour. If we incresase the temperature, the evaporation increases.


The ice albedo feedback has a significant influence on the climate. The ice reflects so much solar radiation back to the atmosphere because it has a high albedo. On the other hand, the ocean tends to absorb more that it reflects because it has a low albedo, for this reason the ocean is heating. This means that the warming of the ocean will melt the sea ice.



The last feedback is the radiation feedback, it is a good example of negative feedback. It works by cooling an object when the temperature is rising. All objects give off radiation, but the warmer a body is the more radiation it gives off.

To sump up, climate can be conceived as a system that involves different components. The mixture of positive and negative feedbacks cooperates to a self-regulation of the climate system.

Wednesday, 27 January 2016

BLANKET EARTH


I enjoyed this article from NASA, it explains breafly what are the causes of the current global warming.

NASA’s article A blanket around the Earth


Greenhouse gases act as a thermal blanket for the Earth. Most of them are surrounding us, for example methane is a gas produced by human activities like agriculture, carbon dioxide is associated to industrial activities and burning fossil fuels, nitrous oxide is a gas produced by soil cultivations practices, CFC's are used in industrial applications but the most abundant greenhouse gas is water vapour that has a great impact in the Earth's atmosphere warm but it also acts like a feedback mechanism to the climate which will be explained later.



 


The globalisation is a fact and not only do greenhouse gases cause a harmful effect  but also the human activities contribute to warm the planet. The industrial activities have raised atmospheric dioxide level during the last 250 years.


Finally, It's reasonable to assume that the sun's energy can cause the climate change but several evidences show that since 1750 the amount of energy coming from the sun remained constant and if the activity of the sun causes the warming, then we would expect to see warmer temperatures in all layers of the atmosphere and that is not happening.
 

Tuesday, 26 January 2016

DIFFERENCE BETWEEN WEATHER AND CLIMATE

According to the NASA web;
The difference between weather and climate is a measure of time. Weather is what conditions of the atmosphere are over a short period of time, and climate is how the atmosphere "behaves" over relatively long periods of time.
In most places, weather can change from minute-to-minute, hour-to-hour, day-to-day, and season-to-season. Climate, however, is the average of weather over time and space. An easy way to remember the difference is that climate is what you expect, like a very hot summer, and weather is what you get, like a hot day with pop-up thunderstorms.









In Ourense where I live the climate is Oceanic type which is generally characterized by mild temperatures all year round, with maximun in summer and minimun in winter, and also rainfall throughout the year, with a maximun in winter and a minimun in summer.





KEY PRINCIPLES OF CLIMATE CHANGE



Key principles of climate change


This is the title of the introduction to the course. It makes me think about the keys, Which are they?
The first video introduces me to the greenhouse effect.
It's fundamental to understanding what keeps our planet warm and why our climate changes over time.The greenhouse, like the rest of the planet, receives incoming radiation from the sun, which passes easily through the glass, just as it does through the atmosphere. Some of that incoming sunlight is absorbed by the surfaces inside the greenhouse. And like all objects, the plants and the soil in the greenhouse re-emit heat radiation at long wavelengths that are invisible to us.
These gases work like a blanket around the planet.   


What are the main greenhouse gases?

Because of all the press coverage it has received in recent years, you may think that carbon dioxide (CO2) is "the big one". Though CO2's role is important, water vapor is actually the dominant greenhouse gas in Earth's atmosphere. Water vapor generates more greenhouse effect on our planet than does any other single gas. After water vapour, in rough order of importance the most important greenhouse gases are carbon dioxide (CO2), methane (CH4) and ozone (O3). There are a number of other gases that contribute to the greenhouse effect to a lesser extent; we'll mention these here in passing for reference, but not consider them further henceforth. These "lesser greenhouse gases" include nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and chlorofluorocarbons (CFCs).

Further information in this link:  The Greenhouse Effect & Greenhouse Gases


What is the albedo?

It's also important the albedo concept (t is the ratio of reflected radiation from the surface to incident radiation upon it. Its dimensionless nature lets it be expressed as a percentage and is measured on a scale from zero for no reflection of a perfectly black surface to 1 for perfect reflection of a white surface.) This is a new concept for me but, it's really useful to understand why people is concern about the melting of ice caps, because it has a extrongly effect on the Earth's temperature.

After watching the video I have tried to reply to this questions:
  • has your understanding of the greenhouse effect changed?
  • should we adopt ‘the blanket effect’ as an analogy instead of ‘the greenhouse effect’?
In my opinion the video explained clearly the basic principles of the greenhouse effect and helped clarify my understanding. Also, I guess we have heard more about CO2 instead of water vapour because there are things we can do in order to reduce emissions.

 

CLIMATE CHANGE: CHALLENGES AND SOLUTIONS

A new course today: 




It's a free online course and organized by the University of Exeter.

In Climate Change: Challenges and Solutions we’ll be exploring:

Week 1

  • The key principles of climate change
  • The climate system, feedbacks, cycles and self-regulation
Week 2

  • Ancient past climate change
  • Recent past climate change
Week 3

  • Signs of climate change
  • How is the global carbon cycle changing?
Week 4

  • Making future projections and modelling future scenarios
  • The geoengineering dilemma
Week 5

  • Impacts on land systems - the cryosphere
  • Impacts on ocean systems - acidification
Week 6

  • Human health and the built environment
  • Climate change and food security
Week 7

  • Mitigation and adaptation
  • Not in my back yard!
Week 8

  • Welcome to the Anthropocene
  • Taking action - reducing our environmental impact