World Climate and Climate Change — NCERT Solutions

Answer:

In short, the empirical system classifies climate by what is observed, while the genetic system classifies climate by why it occurs — i.e., the atmospheric processes and controls responsible for producing that climate.

Answer:

The following types of climates have a very low (small) range of temperature:

1. Equatorial Climate ('Af') – Located near the equator, it receives uniform solar radiation throughout the year, resulting in uniformly high temperatures with very little seasonal variation. The diurnal and annual range of temperature is very low.

2. Marine/Oceanic Climate ('Cfb') – Coastal areas influenced by the sea experience the moderating effect of the ocean, which keeps temperatures equable (cool summers and mild winters), resulting in a very low annual range of temperature.

In general, low-latitude coastal and equatorial regions have the lowest temperature ranges.

Answer:

Sunspots are dark patches on the surface of the Sun associated with intense magnetic activity and increased solar energy output.

If sunspots increase, the following climatic conditions are likely to prevail:

• Increased solar radiation reaches the Earth, leading to a rise in temperature globally.
• This may cause increased evaporation, leading to more rainfall and storminess in certain regions.
• Studies suggest a correlation between high sunspot activity and warmer and wetter conditions on Earth.
• Conversely, periods of very few sunspots (like the Maunder Minimum) have been associated with cooler climates (e.g., the Little Ice Age).

Thus, an increase in sunspots is generally associated with warmer global temperatures and increased precipitation.

Given: Koeppen's climate types 'A' (Tropical Humid) and 'B' (Dry Climates).

Comparison between 'A' type and 'B' type climates:

Conclusion: The fundamental difference is that 'A' type climates are characterised by adequate moisture and high temperatures, supporting lush vegetation, while 'B' type climates are defined by moisture deficiency (evaporation > precipitation), supporting only sparse, drought-resistant vegetation.

Given: Koeppen's 'C' type (Warm Temperate/Mesothermal) and 'A' type (Tropical Humid) climates.

Vegetation in 'A' Type Climate (Tropical Humid):

1. Af (Tropical Rainforest): Dense, multi-layered tropical evergreen rainforests with a huge variety of species — tall trees forming a continuous canopy, epiphytes, lianas, and rich biodiversity. Example: Amazon rainforest, Congo Basin.

2. Am (Tropical Monsoon): Tropical deciduous and semi-evergreen forests; trees shed leaves during the dry season. Example: Indian monsoon forests.

3. Aw (Tropical Savanna): Tropical grasslands (savanna) with scattered trees like acacia and baobab. Example: African savanna.

Vegetation in 'C' Type Climate (Warm Temperate/Mesothermal):

1. Cfa/Cwa (Humid Subtropical): Broadleaf evergreen and mixed forests; also supports grasslands (prairies/pampas) in continental interiors.

2. Cfb (Marine West Coast): Temperate deciduous forests — oak, beech, maple, elm; dense and lush due to adequate year-round rainfall.

3. Cs (Mediterranean): Scrub forests and shrublands (Chaparral/Maquis); drought-resistant, hard-leaved (sclerophyllous) plants like olive, cork oak, lavender. Vegetation is adapted to dry summers and wet winters.

Conclusion: 'A' type climates support the world's most diverse and dense forests, while 'C' type climates support a range from temperate deciduous forests to Mediterranean scrublands, depending on the sub-type.

Greenhouse Gases — Meaning:

The Earth's atmosphere contains certain gases that allow incoming short-wave solar radiation to pass through but absorb and re-emit the outgoing long-wave (infrared) radiation from the Earth's surface. This process traps heat in the lower atmosphere, keeping the Earth warm — similar to the glass panels of a greenhouse. The gases responsible for this effect are called Greenhouse Gases (GHGs).

• Without the natural greenhouse effect, the average temperature of the Earth would be about –18°C instead of the current +15°C.
• However, human activities (burning fossil fuels, deforestation, industrialisation, agriculture) have increased the concentration of these gases, enhancing the greenhouse effect and causing global warming and climate change.

List of Major Greenhouse Gases:

Conclusion: Greenhouse gases are essential for life on Earth in their natural concentrations, but their rapid increase due to human activities is the primary driver of contemporary global warming and associated climate change.