Climate Change Impacts and Mitigation

Over the next century all of Africa is very likely to become dryer and warmer than the global annual mean warming. Due to shift in the rain belt there will be changes in the amount of rainfall, resulting in a decrease of rainfall in northern Sahara and Mediterranean Africa. However, the annual mean rainfall in East Africa is predicted to increase. The average temperature increase is 3-4 degrees Celsius, which is around 1.5 times the global mean. Smaller increases of around 3 degrees Celsius are projected to be found in equatorial and coastal areas while a higher increase of around 4 degrees Celsius will be found in the Western Sahara region.



http://www.grida.no/graphicslib/detail/freshwater-stress-and-scarcity-in-africa-by-2025_4036#

Studies show that Africa is one of the most vulnerable continents to climate change and variability. With the decrease in precipitation, by the year 2020, around 75 million and 250 million people are going to be exposed to increase water stress. As you can see from the picture to the left, the northern and eastern African countries will feel either water stress or have a scarcity of water by the year 2025. This also means that agriculture production will suffer; the area ideal for agriculture, and the length of growing seasons will decrease. Overall, this will negatively affect malnutrition in Africa and affect food security. To make things worse, towards the end of the 21^st century there is an expected sea-level rise, which will affect low lying coastal areas.

African farmers have started to develop adaption options to cope with future climate variability; however it may not be sufficient for this upcoming climate change. African countries already tackle arid conditions making agriculture difficult. By 2020, crop yield in some countries will have a decrease of as much as 50% and by 2100 crop yield will have a decrease of around 90%. Currently around 25% of Africa’s population experience high water stress with an increase of between 75-250 million and 350-600 million people by the 2020s and 2050s. Even without climate change, several countries in northern Africa will exceed the limits of their usable water resources before 2025.



http://www.grida.no/publications/vg/africa/page/3116.aspx

There are many threats resulting from climate change in Africa. It was a toss-up between the decrease of agricultural production/food yield and increase stress of water supply, however the threat that interests me the most is the overall decrease of water supply. As you can see from the image to the right, more than half of the countries in Africa will feel the increase of stress of water supply in 2025, This was the most interesting threat to me because dehydration kills people faster than starvation. Decrease of water ultimately has the biggest impact because without water agriculture will rapidly dwindle down. It affects so many other aspects other than dehydration. Plus, a portion of Africa struggles with their current water supply. When this problem increase resulting from climate change, it will be the biggest problem Africa faces.

 

Severe Weather in Egypt

 

Today I am going to share with you some of the ins and outs of cyclones and hurricanes. How does a tornado even occur? Wherever there is a thunderstorm, there is a chance of a tornado. After all, tornadoes are formed by severe thunderstorms. Generally, there are three steps for tornado development. First tornadoes need vertical wind shear. This is when wind increasingly blows faster as height increases. This vertical wind shear helps wind topple over causing a spinning, rotating body of air at the surface called a vortex tube. In the second step, an updraft from a thunderstorm lifts the vortex tube off the ground which is pulled into a thunderstorm. Once the vortex tube is vertical, it is called a mesocyclone. The mesocyclone intensifies as its walls contract, which makes wind speeds increase. A tornado occurs once the mesocyclone reaches the ground.  

In the United States tornadoes travel from west to east, with a counter-clockwise rotation. Since tornadoes travel where ever the wind takes them, it is just natural that tornadoes in the US will move in this direction resulting from the Westerlies. As you may have guessed it, if tornadoes travel from west to east, one will first spot the signs of a tornado in the western skies. According to the Storm Prediction Center, there are 1,300 plus or minus a few hundred tornadoes observed in the US per year (The Online Tornado FAQ, NOAA). Unlike the US, Egypt has an average of zero tornadoes per year (WikiAnswers).
 

http://www.windows2universe.org/earth/Atmosphere/tornado/agri_map.html

The picture to the right shows a global map of tornado occurrences. The red dots are the location of previous tornadoes and the green shaded area are agricultural areas. When I first saw this picture I noticed that the red dots and the green area are mostly in the same place. This is because both, tornadoes and agriculture need moisture. Tornadoes do happen in Egypt, however it is very rare. If there is ever a tornado in Egypt it will result with minor damages and there will NEVER be a tornado in Cairo. If you look at the Global map, Egypt is not close to any of the tornado "hot spots."

Over time, tornado occurrences have appeared to increase. I don't think tornado occurrences have increased, just more of the tornadoes are being observed. This is probably due to rapid technological advancements. It is now easier to observe and measure tornadoes and other weather related phenomenon's. Even today there are tornadoes that come and go with out anyone being able to record the data. This is due to tornadoes touching down on areas that are uninhabited.

 

http://web.mit.edu/12.000/www/m2010/finalwebsite/background/hurricanes/hurricanewhatis.html

As you can see in the picture above, hurricanes are born in the tropics. The tropics is ideal for hurricane formation because it comprises of the three main requirements that hurricanes need to form. The three main requirements for hurricane formation are warm ocean temperatures for evaporation, deep warm ocean layer of at least 200 meters in depth and Coriolis. The ideal ocean temperature needs to be above 80 degrees Fahrenheit, which only happens equator-ward of 20 degrees North or South. Not only does the surface ocean temperature have to be warm but the deep layers as well because when the wind churns up the water it is still has to be warm in order to produce a hurricane. This also only happens equator-ward of 20 degrees North and South. The confusing thing is that the term for hurricane depends on the region it is occurs. In the Atlantic and East Pacific it is called a hurricane while hurricanes in the Indian Ocean near Australia are called Cyclones and off the coast of China and Indonesia they are called Typhoons.



 

http://www.wunderground.com/blog/JeffMasters/remainder-of-july-hurricane-outlook

Generally in the United States, hurricanes travel in a "C" path. The picture above shows the paths of different hurricanes near or over the United States. You can notice that most of the hurricanes are traveling on this "C" path. This is the dominant path that hurricanes travel in the US due to multiple reasons. First of all since we have a warm gulf stream the Hurricane will more likely follow that path up. Secondly, hurricanes need water! So once a hurricane reaches land, there isn't any water to fuel this gigantic storm. On land there is also friction. Terrain cuts off the hurricanes circulation and steals the storms moisture. The storm will eventually travel back over cold water where it will decay. According to the Hurricane Research Division, the average number of hurricanes that hit the US per year is 1.7 (NOAA).
 

Hurricanes do not happen in Egypt. The average number of hurricanes that hit Egypt annually is zero (Wikianswers).