Lesson 4: Climate and Vegetation Regions, Climate Change and Egypt's Green Efforts

• Climatic region: an area defined geographically on the Earth sharing general climatic characteristics in temperature, winds and the amount and season of rainfall.
• Mediterranean region: a warm temperate region lying between latitudes 30° and 45° north and south, on the west of the continents; its climate is hot dry in summer, warm rainy in winter; its vegetation is evergreen forest — olive and oak — and steppe grass.
• Hot desert region: a dry region between 18° and 30° north and south, on the west of the continents and in the interior; marked by a large daily and annual temperature range, very hot by day and in summer, very cold by night and in winter, and rare rain.
• Daily and annual temperature range: the daily range is the difference between the highest and lowest temperature recorded within 24 hours; the annual range is the difference between the mean of the hottest month and the mean of the coldest. It is large in desert areas and small in coastal areas.
• Climate change and global warming: long-term transformations in temperature and weather patterns caused by rising emissions of greenhouse gases (carbon dioxide and methane) from industrial activity and the burning of fossil fuel.

• Law of the temperature range:
  Daily range = T_max − T_min (within the day)
  Annual range = mean(hottest month) − mean(coldest month)
  The range is very large in the deserts and very small on the coasts.
• Latitude zonation of the regions: Tropical 0–30° → Warm temperate 30–45° → Cool temperate 45–60° → Polar 60–90° — temperature steps down from the equator toward the poles.

• Mediterranean region — west of the continents: hot dry summer, warm rainy winter; evergreen forests such as olive.
• Warm temperate "Chinese" region — east of the continents: hot rainy summer, warm rainy winter; rain falls all year and increases in summer, and the region is exposed to tropical typhoon storms.
• Key contrast for the exam: both lie in the same latitude band; they differ because one faces the west coast and the other the east coast of the continent.

• Cool temperate (45° – 60°): as in western Europe — moderated by the sea and the westerlies, with rain through the year.
• Cold regions (60° – 90°): the tundra, frozen and treeless, and the mountain region, where altitude rather than latitude produces the cold.
• In the mountain region the lapse rate applies: 1 °C per 150 m, so snow caps high peaks even inside hot lands.

• Egypt lies astronomically between 22° and 31.36° north, and the Tropic of Cancer crosses its south.
• This position puts more than 85% of Egypt's area inside the hot desert and semi-desert region, while the northern coastal strip facing the Mediterranean belongs to the Mediterranean region.

The prevailing regions

• 1. The Mediterranean region — Mariout, the Sinai Peninsula and the north coast, extending from Sallum in the west to Rafah in the east. Temperate in summer and winter thanks to the Mediterranean's influence; it is the rainiest region of Egypt, reaching about 200 mm per year in Alexandria and Marsa Matruh, in winter.
• 2. The semi-desert region — Middle Egypt and the southern Delta: Greater Cairo, Fayoum, Beni Suef, Minya and Asyut. Its climate is continental: the Mediterranean's influence weakens, rain is scarce, summers are hotter and winters colder.
• 3. The hot desert region — Upper Egypt, the southern valley, the Western and Eastern Deserts: Sohag, Qena, Luxor, Aswan and the New Valley. Complete drought and very rare rain, an enormous daily and annual range; daytime summer temperatures pass 45 °C and fall in winter.
• 4. The mountain-highland region — the mountains of South Sinai and the Red Sea hills. Here the relief factor appears, with temperature falling 1 °C per 150 m, and snow falls in winter on Mount Catherine and Mount Moses.

Egypt and the world face an existential environmental challenge in climate change caused by carbon emissions and global warming. The main expected effects on Egypt are:

• Coasts and Delta: melting polar ice raises the level of the Mediterranean, threatening submergence of parts of the sandy beaches of Alexandria and Port Said and the salinization of the fertile farmland of the northern Delta.
• Water resources and the Nile: fluctuation of rainfall over the Ethiopian Plateau and the equatorial sources demands strict anticipatory management of the water stock in Lake Nasser.
• Agricultural production: higher temperatures raise evaporation, reduce the yield of winter crops such as wheat, and increase the demand for irrigation water.

• Egypt successfully hosted the World Climate Conference COP27 in Sharm El-Sheikh.
• It launched the National Climate Change Strategy 2050.
• It expanded green energy projects: green hydrogen, the Benban solar power station in Aswan, and the Zafarana and Gabal El-Zeit wind farms.
• These efforts link Egypt's location and energy choices to the protection of its coastline, its farmland and the rights of future generations.

• Read the map and identify the climatic region of each Egyptian city, with the reason and the climatic effect: Alexandria, Aswan, Saint Catherine.
  • Alexandria → Mediterranean region: it lies directly on the north coast facing the Mediterranean; temperate in summer and winter with heavy winter rain.
  • Aswan → hot desert region: it lies in the far south in the dry tropical belt below the Tropic of Cancer; very hot in summer, extremely dry, with a large daily range.
  • Saint Catherine → highland/mountain region: a towering mountain area of South Sinai, above 1600 m; intensely cold with winter snow because of the great height.
• Quick technique: remember the lapse rate — height lowers temperature 1 °C per 150 m — which creates a cold mountain climate in the heart of hot lands.
• Give a reason: the annual range is small in Port Said and large in Aswan. — Port Said is coastal, and water gains and loses heat slowly; Aswan is inland and arid.
• Compare: the Mediterranean region and the Chinese region. — Same latitude band (30°–45°); the Mediterranean is on the west with rain in winter only, the Chinese on the east with rain all year and typhoons.